WO2014011910A2

WO2014011910A2 - Golf club making and golf club prescribing system

Info

Publication number: WO2014011910A2
Application number: PCT/US2013/050119
Authority: WO
Inventors: Terry B. KOEHLER
Original assignee: Eidolon Brands, Llc
Priority date: 2012-07-11
Filing date: 2013-07-11
Publication date: 2014-01-16
Also published as: US20140018182A1; WO2014011910A3

Abstract

A set of correlated golf clubs (10) may generally include a plurality of golf clubs (10). Each golf club (10) in the plurality of golf clubs may have a distinct mass distribution (74) that creates a distinctive visual appearance to a golfer. Each successively lower lofted (30) golf club (10) has a redistribution of mass towards a sole (26), a topline (22), a toe (50), and a heel (52) to optimize ball flight characteristics for each individual successively lower lofted golf club (10).

Description

GOLF CLUB MAKING AND GOLF CLUB PRESCRIBING SYSTEM

Background

Golf is a game in which a player, or golfer, swings a golf club to strike, or hit, a golf ball towards a target, such as a golf hole on a golf course. During a round of golf, the golfer attempts to sink the golf ball with as few strokes as possible into each hole on the golf course, which typically has 9 or 18 holes.

The golf club may include a shaft with a grip on a first end of the shaft and a clubhead on an opposing second end of the shaft. The clubhead is the part of the golf club that strikes the golf ball. The golf club can take a variety of forms, traditionally categorized such as putter-type, wood-type, iron-type, wedge-type, and more recently, hybrid-type. The different types of golf clubs are intended to provide the golfer with an assortment of options to hit shots for a variety of distances and from a variety of playing conditions. The golf club type may be determined by the clubhead, the shaft, and the grip. Summary

Various embodiments disclosed herein are generally directed to a set of correlated golf clubs and methods for selecting and making the same.

In accordance with some embodiments, a set of correlated golf clubs may generally include a plurality of golf clubs. Each golf club in the plurality of golf clubs may have a distinct mass distribution that creates a distinctive visual appearance to a golfer. Each successively lower lofted golf club has a

redistribution of mass towards a sole, a topline, a toe, and a heel to optimize ball flight characteristics for each individual successively lower lofted golf club.

In accordance with some embodiments, a correlated set of golf clubs may include a plurality of golf clubs. Each golf club includes a sole opposite a topline, a toe opposite a heel, and a striking face opposite a back surface. The back surface has an upper back portion located that is closer to the topline than to the sole, and a lower back portion that is located closer to the sole than to the topline. A first thickness located between a substantial entirety of the upper back portion and the striking face may be uniform. A second thickness located between a substantial entirety of the lower back portion and the striking face is non-uniform. The first thickness is less than the second thickness. Each golf club has a loft and a mass. The plurality of golf clubs may include at least 3 golf clubs. The mass is distributed continuously and progressively more towards the sole, the topline, the toe and the heel for each golf club at the loft consecutively and successively lower in a range of lofts for the at least 3 golf clubs compliant under the Rules of Golf.

In accordance with other embodiments, a computer-implemented method may generally include a number of steps. Identification for at least one golf club of a golfer may be acquired in a first memory from a network accessible device. Specifications for the at least one golf club may be selected from a first database of available golf clubs in a second memory responsive to the identification of the at least one golf club. At least one suggestion for a set of golf clubs may be rendered from a second database of available golf clubs in a third memory responsive to the specifications for the at least one golf club. The at least one suggestion may be transferred for display in a graphical user interface output slot of the network accessible device.

In accordance with another embodiment, a method of manufacturing the clubhead may include a number of steps. A tool from a plurality of tools for manufacture of a clubhead is selected. The tool is engineered for manufacture of the clubhead with an engineered loft of approximately 3° different than an engineered loft of another tool in the plurality of tools. The clubhead is manufactured using the selected tool. A manufactured loft of the clubhead is measured. The manufactured loft is adjusted to a target loft. The target loft may be within approximately 1° of the engineered loft for the selected tool

These and other features and advantages which may characterize various embodiments can be understood in view of the following detailed discussion and the accompanying drawings.

Brief Description of the Drawings

FIG. 1 shows a side view of a golf club in accordance with various embodiments.

FIG. 2 illustrates a back view of a clubhead of FIG. 1 in accordance with some embodiments. FIG. 3 shows a bottom view of a clubhead of FIG. 1 in accordance with some embodiments.

FIG. 4 illustrates a chart of possible makeups for a set of golf clubs in accordance with various embodiments.

FIG. 5 provides a flow chart for a routine illustrative of steps that may be carried out in accordance with various embodiments.

FIG. 6 provides a functional block representation of a network based system in accordance with various embodiments.

FIG. 7 shows an example input screen for the network based system in accordance with various embodiments.

FIG. 8 shows an example screen for the network based system in accordance with various embodiments.

FIG. 9 shows an example database for a set of golf clubs.

FIG. 10 provides some dynamic swing parameters.

FIG. 1 1 provides a flow chart for a routine illustrative of a golf club fitting method that may be carried out in accordance with various embodiments.

FIG. 12 provides a flow chart for a routine illustrative of a golf club prescription method that will be carried out in accordance with various embodiments.

FIG. 13 provides a flow chart for a routine illustrative of manufacturing a golf club in accordance with various embodiments.

FIG. 14 shows a golf club with a depression in accordance with various embodiments.

FIG. 15 displays a series of golf clubs in cross-section in accordance with various embodiments.

FIG. 16 demonstrates a series of golf clubs focused on the back surface in accordance with various embodiments.

FIG. 17 shows a golf club with an insert in accordance with various embodiments.

Detailed Description

The present disclosure generally relates to a golf club fitting system and method. Golf can be played with a regulation set of golf clubs. In addition, the regulation set of golf clubs can be or has historically been further divided into various subtypes. For example, the regulation current traditional set of golf clubs may include a putter, a driver, a set or selection or group of wood-type clubs, a set or selection or group of iron-type clubs, a set or selection or group of hybrid-type clubs, a set or selection or group of wedge-type clubs, etc. These sets or selections or group of various types of golf clubs may create abrupt transitions between the various club types, as for example between the iron-type clubs and the wedge-type clubs.

After discussing the various type golf clubs, the golf club fitting system and method for fitting or prescribing a first matched set of golf clubs, or a first selection of golf clubs, to blend seamlessly with a second set or selection of golf clubs in the set of regulation golf clubs will be explained beginning with FIG. 6. While the golf club fitting system and method is discussed in terms of a set of high loft scoring clubs and a set or selection of iron-type clubs, it will be understood that these sets and/or selections of clubs are only intended to provide a concrete example. The types of clubs described are not limiting.

The putter-type club, also known as "putter", is a specialty club that is designed to roll the golf ball across the grass, such as a putting green where the golf hole is located. The clubhead of the putter-type club can be made of iron or other suitable material. The putter has a loft not exceeding 10° (ten degrees) per the Rules of Golf, which are defined by The Royal & Ancient Golf Club and the United States Golf Association. The shaft length of the putter-type club can be the shortest to the longest of all the club types, depending on the golfer preference and the Rules of Golf.

Wood-type clubs are called "woods", because the wood traditionally had a clubhead made of wood, such as a block of permission, although the clubhead of the wood-type club was often made of other woods, laminated, etc. Over the past 20 years or so, the clubhead of the wood-type club has been made of various metals, though the clubs typically are still referred to as "woods" in respect of the game's traditions. Wood-type clubs usually have a large clubhead relative to the clubhead of the other club types. The range of loft found in woods can be less than 10° to more than 20°. The wood-type club is usually meant for hitting the golf ball a long distance, such as, but not limited to, from a tee box or fairway, and the wood-type club usually has a longer shaft than any of the other golf clubs.

Iron-type clubs historically had a clubhead made of iron, however in modern golf manufacture, iron-type clubs may have a clubhead made of various types of steel, such as carbon steel or stainless steel, although other metals and materials may be used to make the clubhead. These clubs are still typically referred to as "irons" in respect of the game's traditions. The clubhead of the iron-type club traditionally was forged, but modem iron-type clubheads are also commonly cast or formed by other suitable manufacturing technique. The iron-type clubs usually have progressively shorter shafts than the wood-type or hybrid-type golf clubs as the loft of the irons increases.

The iron-type club is traditionally made, marketed and sold in sets of 6-9 clubs, with loft differences between clubs of 3-5°, lofts in the range of about 18- 50°, and shaft lengths that decrease incrementally between clubs as the loft of each club increases. The irons will almost always share the same visual appearance and similar distribution of mass throughout the set, though some sets have been introduced to market with two or three different designs across the range of lofts in the set. The general arrangement of incremental changes in lofts and shaft lengths is intended to allow the golfer to have an assortment of iron clubs from which to choose to hit the golf ball a variety of reasonably predictable distances, such as, but not limited to, from the tee box on a par 3 or the golfer's approach shot to a green.

Wedge-type clubs, also known as "wedges", can be characterized as a specialty club with a clubhead typically made of a steel alloy, such as carbon steel or stainless steel, although other metals may be used to make the clubhead. The wedge clubheads are typically either cast or forged in manufacture. Wedge-type clubs generally have loft from 46° to in excess of 60°. The wedge-type club usually has a shorter shaft than the highest loft iron-type club, and the wedge-type shafts typically are progressively shorter in length for wedge-type clubs of increasing loft angles.

The specialty nature of the wedge-type club may be identified by a generally low center of mass and higher loft than the iron-type clubs. In most commercial presentations of wedges, the weighting (or weight distribution) and visual design of the wedge-type club is essentially unchanged between wedge clubheads with different lofts.

The wedge-type club generally features a wider sole area than the iron-type club and a feature called "bounce" where the bottom of the club angles downward and away from the leading edge of the clubhead. The leading edge is where the face of the clubhead meets the sole of the clubhead. The bounce is designed to make the wedge-type club effective from a variety of lies of the golf ball, such as the golf ball lying on sand in sand traps, also known as bunkers, and deep rough. The market may offer the golfer a variety of specialized bounce angles to choose from within any given loft designation of the wedge-type club. The iron-type club may have bounce also, although the bounce on the irons may not be as large or as specialized as the bounce found on wedges.

The hybrid-type club, also known simply as "hybrid", may be considered a cross between the wood-type club and the iron -type club. The clubhead of the hybrid-type club may be made of metal and be hollow like the modern metal wood-type club, but the clubhead of the hybrid-type club is usually smaller than the wood-type club. In some instances, the hybrid-type club may be made of wood or other material. It is often easier for the golfer to hit the golf ball well with the hybrid-type club than a long iron (lower loft and lower number) of the iron-type club, so the golfer may substitute one or more hybrid-type club for one or more iron-type club in a set of golf clubs. The loft of the hybrid-type club typically ranges from 15- 17 degrees up to as high as 30 degrees. The hybrid shaft is typically longer than the longest iron shafts and shorter than the shortest wood shafts. Some manufacturers produce sets of golf clubs in which some or all of the iron-type clubs of the traditional set of golf clubs are replaced with hybrid-type clubs.

The shaft of the golf club may be a tapered tube made of metal, which is usually steel, or carbon fiber composite, which is termed graphite. Other materials may be found in golf shafts. The shaft of the golf club may be roughly 0.6 inch in diameter near the first end of the shaft to which the grip is attached and often a lesser diameter at the second end of the shaft to which the clubhead is attached. The shaft is typically 34 to 48 inches in length, but may be more or less, depending on preference and the Rules of Golf. Shafts are quantified in different ways, such as by the flex or weight of the shaft. The shaft flex is the amount that the shaft will bend when placed under a load. Under the same load, the stiffer shaft will not flex as much as the less stiff shaft. Most shaft makers offer a variety of flexes and other shaft characteristics, although there is currently no industry standardization. In order from most flexible to most stiff shaft flex, common shaft flexes are L (for lady), A (for amateur or senior), R (for regular), S (for stiff), and X (for extra stiff). In another scheme of shaft flexes, the most flexible to most stiff shaft flex is A (for senior, women, junior), Regular, Firm, and Firm+. Wedges may have their own special shaft flex known as wedge flex, which can be quite stiff in comparison to the shaft flex used for iron-type clubs. Of course, other schemes for identifying shafts of various flexes are possible. Torque measurements can also be used to quantitate shafts.

The grip of the club is attached to the opposite end of the shaft from the clubhead, and is the part of the club the golfer holds on to while swinging the golf club. The grip can be made of leather strips wrapped around the shaft. Modern grips may be a one-piece "sleeve" made of rubber, synthetic or composite material that is slid over the shaft and secured to the shaft with an adhesive.

For much of the 20th century, a set of golf clubs was fairly well defined. The golfer may use up to 14 golf clubs in a regulation round of golf under the Rules of Golf. The set of golf clubs would typically include a putter, 1 -3 wood- type clubs, 8-9 iron type clubs, and 1-3 wedges. The irons previously had names like "mashie", "niblick", etc., but for many decades the individual irons have been designated by numbers. Again, the low number iron has the lowest loft and the high number iron has the higher loft. A typical set of irons were designated "1", "2", "3", "4", "5", "6", "7", "8", and "9". The typical set of irons were further subdivided into long irons (" 1", "2", "3"), middle irons ("4", "5", "6"), and short irons ("7", "8", "9"), although there might be some variation in the subdivisions. By the mid 20^th century, an iron designated "P" or "Pitching Wedge" was added to the short end of the set of irons, and had the highest loft feature in the set of irons.

By the 1970s, it became increasingly more common for the driver, or lowest-lofted wood type club to be purchased separately from the other wood-type clubs, and for the wedges to also be purchased separately, selected by loft.

Simultaneously, drivers and wedges commonly began to be manufactured with the identifying mark of the actual loft of the drivers and wedges, for example, "9.5", ' 12", "56", "60", of the club itself. In the early 1990s, a new category of club was introduced and called the "hybrid", which was universally accepted by golfers to provide improved playability for golfers of all skill levels for the lower lofted clubs generally included in the set of irons. In today's golfers' bags, it is common to find a wide assortment of brands and models of clubs from the driver to putter, and the notion of "matched sets" of golf clubs has become difficult to attain for the golfer.

It should be noted that there are no universal industry standards over the loft and shaft length of iron-type clubs of a given designation. Additionally, over the past few decades, golf club design and manufacturing technology have led to a progressive strengthening of lofts of the iron-type golf clubs. In illustration of this trend, the iron-type club numbered "9" typically was built with a loft of 45-47 degrees in the 1950s. As weighting technology advanced and the power of golfers' swings increased, higher ball flights on full golf swings resulted from iron-type clubs of a given loft, so golf club designers began to progressively strengthen, i.e., decreased, the lofts of irons. By 2010-1 1, it was not untypical to find "9-irons" of 40-43 degrees of loft, and a few "9-irons" can be found even lower loft than that. Following this trend, golfers have become more likely to carry 2, 3 or even 4 wedge-type clubs to compensate for the reduction of high loft clubs in the set of irons.

A modern set of golf clubs might include the driver, the putter, 1-3 woods, 1-5 hybrids, 4-9 irons, and 2-5 wedges. It is not unheard of for a player to have irons starting at "4", "5", or even higher numbered. The "P" club or "pitching wedge" is generally considered part of, and sold with, the modern set of irons, with said pitching wedge having a loft of 4-5 degrees more than the designated "9-iron", typically in the range of 43-47 degrees, with some manufacturer models having even less loft than that. The set of modern iron-type clubs may include a gap wedge or approach wedge, also, with 4-5 degrees more loft than the pitching wedge.

While this design evolution in the iron-type club has caused the golf ball to fly progressively further than before with a club of a given designated number, the evolution has left the golfer with fewer club selection options when in prime scoring range of the green and hole, and inconsistent distance differentials between clubs. It is desirable for distance gaps between clubs to be the same or follow some even progression to help the golfer navigate their way around the course with precision in their approach shots, those shots played with the intent of putting the ball on or near the green.. The prime scoring range, or scoring zone, might be considered the distance from the hole that the golfer can strike the golf ball with one of the higher-lofted irons or wedges, using a full or partial swing so that the golfer can expect to have a realistic chance of either making the shot or leaving the ball close enough to the hole to give the golfer a reasonable chance of needing only one more shot to finish the hole. These shots are typically played with the higher- loft clubs in the set, whether they be of the iron-type or wedge-type. To optimize performance of the golfer in the scoring zone, these golf clubs can be created with characteristics to optimize ball flight, ball trajectory, ball spin, feel and forgiveness of mishits on full or partial swings that strikes the golf ball.

For many golfers, the iron-type clubs with loft of 41° or greater and the wedges are used in the scoring range. The thin face and perimeter weighting that has become increasingly more common to iron-type club modern designs in this range of lofts, such as cavity back clubs, may not produce as reliable golf ball flight trajectory, distance control, spin, and feel for the golfer as may be found with iron-type clubs featuring a thicker face and more centralized weighting

Most golfers also choose to use several wedge-type clubs for their short range shots. In the modern art, wedge-type clubs are typically identified by an indicia on the sole of the club which designates the designed-in loft of that particular wedge-type club, i.e. "48", "54", etc. For the most part, the industry only offers wedge-type clubs in even numbered lofts, though it is not uncommon for these clubs to be altered after production to make their actual loft measurement an odd-number either stronger or weaker than the indicia would indicate. Wedge-type clubs are typically not purchased in sets, and often have no thoughtful correlation to the golfer's iron-type clubs with regard to the exact lofts, lengths, shaft characteristics, etc. There exists much less design differentiation between wedge- type clubs from the various manufacturers than is seen in the iron-type club category. Almost all wedge-type clubs feature a concentration of mass along the back of the bottom portion of the clubhead, with very thin upper portion behind the upper half to 2/3 of the clubface striking surface. It should be noted that this placement of mass tends to create a very high ball flight when the ball is struck at higher swing speeds.

Oddly, during this evolution of iron-type designs and manufacturing, few innovations have been introduced to the wedge-type club category, other than the offering of lower loft options, various bounce configurations and specific groove geometry. For instance, a "sand wedge" (specialty wedge optimized for hitting a golf ball from sandy lies) still often has a loft of about 55-56°, so strengthening the set of irons may create a gap in loft between the clubs in the set of irons and the sand wedge. This gap in loft may be filled with a "gap wedge", also known as an "approach wedge" and by other names. An observation of wedge-type clubs dating back to those of the 1980s and 1990s and even as far back as the 1940s and 1950s reveals very little change in the design cosmetics, weighting or other design parameters of wedge-type clubs from most golf club manufacturers up to the current year

As many as 30-60% of the golfer's strokes taken in between those hit from the tee box area on longer par-4 and par-5 holes, and those strokes hit with a putter on the green area are likely to be played with the high loft clubs of 41 degrees of loft or more. That is, as many as 30-60% of the golfer's strokes in a typical round of golf are taken in the scoring range. Since this scoring range is where precision is most required to achieve optimum scoring performance (i.e., lowest score), a set of scoring clubs that are precisely designed, manufactured and crafted to give the golfer the most precise distance control and directional accuracy that can be achieved may be useful.

A thicker cross-section of the clubhead behind the point of impact of the clubhead with the golf ball may deliver more consistent distance control and lower ball flight trajectories, which are qualities that are desirable in the scoring range of the hole. However, most golfers are hindered in trying to achieve this precision by having higher-numbered iron-type golf clubs and wedge-type golf clubs that have dramatically lower center of mass and thin faces, as may be found in cavity back clubs and wedge-type clubs, behind the impact point. Furthermore, as the loft of the iron- or wedge-type club increases, golfers of all skill levels may have difficulty hitting golf shots with full swings having the desired lower trajectories and more precise distance control that result. Ball flight characteristics, such as trajectory, from golf balls struck with higher lofted golf clubs may require that optimum weight distribution in the clubhead change slightly and incrementally as the loft of the club increases in the set of golf clubs.

Finally, in almost every golfer's set of clubs, the dramatic design and manufacturing differences between their iron-type clubs and their wedge-type clubs often causes an awkward and inefficient transition in feel and performance, ball flight and distance control which is not conducive to optimum performance for the golfer when in prime scoring range of the hole.

We have disclosed herein a new category of golf clubs known as "scoring clubs" that are optimized for the golfer's performance in the scoring range. In the scoring range, the golfer may need to use the same golf club, at different times during the round, to precisely strike the golf ball a shorter distance with a slower swing speed or a longer distance with a faster swing speed. In scoring clubs, swing speed, loft, and weight distribution of the clubhead influence the ball flight or trajectory of the golf ball struck by the scoring club. The initial trajectory of the golf ball struck by the golf club is important for distance control. At slower swing speeds, the loft of the golf club is more important in determining the ball flight. As the swing speed of the golf club increases, the weight distribution in the clubhead has a greater influence on the ball flight. By progressively moving the center of gravity of the clubhead from the sole towards the topline of the clubhead, the scoring clubs may be able to provide an optimum ball flight at slow swing speeds and faster swing speeds. This movement in the center of gravity of the clubhead from the sole towards the topline of the clubhead of the scoring club may be in comparison to the center of gravity of iron-type golf club and the center of gravity of the wedge-type golf club.

These and other features and benefits can be understood beginning with a review of FIG. 1 which depicts a golf club 10 constructed in accordance with various embodiments. The golf club 10 includes a shaft 12, a grip 14, and a clubhead 16. The grip 14 is attached to a first end of the shaft 12 by a fastener such as bonding agent, adhesive, epoxy resin, cement, glue, etc. The clubhead 16 is attached to an opposing second end of the shaft 12 by a fastener such as a bonding agent, adhesive, epoxy resin, cement, glue, screw, bolt, nail, rivet, etc. The clubhead 16 may include a hosel 18, a striking surface 20, a topline 22, a back surface 24, and a sole 26. The hosel 18 is used for attachment of the clubhead 16 to the shaft 12. The striking surface, also known as the face, 20 is configured for use by the golfer in striking the golf ball (not shown). The striking surface 20 may have grooves (not shown), for example, grooves approved in rules of the Royal & Ancient and the United States Golf Association. The striking surface 20 may be substantially flat, which is consistent with the rules of Royal & Ancient and the United States Golf Association. The striking surface 20 is slanted back from a center line 28 of the shaft 12. An angle 30 between the striking surface 20 and the center line 28 is known as the loft of the golf club 10. Each golf club in a set of correlated golf clubs will typically have a different loft, such as a difference in loft of 3-5 degrees between each consecutive golf club. A correlated set typically share a consistent look, such as consistent markings, color combinations, or type of polishing or texture of the clubhead and shaft, etc., however in a correlated set of scoring clubs, the characteristics of the clubs may be different from club to club to optimize scoring performance of the golfer.

The topline 22 is disposed between the striking surface 20 and the back surface 24.

The sole 26 is a surface of the clubhead 16 opposite the topline 22, and the sole 26 is disposed between the back surface 24 and the striking surface 20. The sole 26 is a portion of the golf club that is configured to engage the ground 32 during a swing of the golf club 10 by the golfer to strike the golf ball. The sole 26 may take a variety of shapes and configurations.

In certain embodiments, the configuration may be derived from U.S. Pat. No. 5,301 ,944 issued to Terry B. Koehler, which is herein incorporated by reference. The sole 26 shown has a first positive bounce angle (also known herein as primary bounce) 34 and a second positive bounce angle (also known herein as lead bounce) 36. The first portion 38 of the sole 26 may be substantially flat or substantially curvilinear, or some combination of both. Similarly, the second portion 40 of the sole 26 may be substantially flat of substantially curvilinear, or some combination of both.

A thickness 48 of the clubhead 16 between the striking surface 20 and the back surface 24 may sometimes be known as face thickness. The thickness 48 may be adjusted between the sole 26 and topline 22 to optimize the center of gravity of the clubhead 16 above the ground 32 and between the striking surface 20 and the back surface 24 to optimize the center of gravity of the clubhead 16 towards the face 20 or the back surface 24. Typically, the muscle back type club is thicker than the cavity back type club where the clubhead 16 is intended to impact golf ball.

The golf club 10 is shown as a right-handed version, but a left-handed version is contemplated.

FIG. 2 shows a back view of the clubhead 16. The clubhead 16 provides a toe 50 at a first end of the clubhead and a heel 52 at an opposing second end of the clubhead. The back surface 24 may provide one or more back portion(s), such as a first back portion 54 and a second back portion 56 shown. The first and second back portions 54, 56 may provide a cavity back or muscle back type design. The size and type of the first and second back portions 54, 56 may be the same or different between various clubs in the set of scoring clubs. A cavity back type club has a predetermined amount of the metal across the back surface 24 of the clubhead 16 removed, which allows the club maker to re-position the weight from the back surface 26 to other locations, such as the perimeter of the clubhead, e.g., towards the topline 22, sole 26, toe 50 and heel 54. A similar effect can be achieved by using materials of different densities to make the clubhead.

The clubhead 16 has a center of gravity that may be determined in three dimensions. A vertical location of the center of gravity may be determined by how far the center of gravity is from the sole 26. A horizontal location of the center of gravity may be determined by how far the center of gravity is from the center of the shaft in the hosel 18 of the clubhead 16. A depth location of the center of gravity may be determined by how far the center of gravity is from the striking surface (see 20 in FIG. 1).

Re-positioning weight further away from the center of gravity of the clubhead 16 may create a higher moment of inertia about the vertical axis of the center of gravity of the clubhead, such that the clubhead may twist less from an off-center hit of the golf club on the golf ball (not shown) in the horizontal direction (i.e., the direction between the toe 50 and the heel 52). By twisting less from an impact of the golf ball towards the toe 50 or the heel 52, the clubhead 16 may be more forgiving to provide longer and straighter golf shots. In other words, the weight distribution of the clubhead 16 may optimized to enhance the horizontal "sweet spot".

Rotation of the clubhead about the other axes of the center of gravity of the clubhead is limited by the golfer holding the shaft that is connected to the clubhead during the golf swing. The peripheral weighting of the cavity back iron-type club may not be able to provide much "forgiveness" for the golf ball struck higher or lower than the optimal point of impact for the club face. Certain cavity back designs may limit the performance of the golf club in the scoring range, because the mass of the clubhead at impact may be different depending on where the golf ball is struck on the golf club from the sole to the topline. The different amount of mass of the point of impact may lead to different ball flight trajectory and distance.

By optimizing weight distribution in the clubhead, e.g., through a combination of muscle back and cavity back features, the scoring club may provide more consistent mass at the point of impact between the clubhead and the golf ball. By having more consistent mass over the face of the club from the sole to the topline, the struck golf ball may be more likely to travel a consistent distance and trajectory. For example, whether the golf ball is struck on the second groove, fifth groove, or seventh groove of the clubhead, if the mass in the scoring club is optimized for more even distribution from the sole to the topline of the golf club, then the scoring club may provide more consistent mass at the point of impact between the golf ball and the clubhead. The more consistent mass of the clubhead at impact of the golf ball for the golf ball struck on various parts of the striking surface from the sole to the topline may provide more consistent trajectory and distance of the golf ball struck with the scoring club than could be achieved with the iron-type club or the wedge-type club.

Of course, the back surface may have a muscle back, i.e., clubhead weight more evenly distributed across the back surface 24 of the clubhead 16. The first back portion 54 of the back surface 24 may have a muscle back, and the second back portion of the back surface 24 may have a cavity back, or vice versa. The first and second portions 54, 56 may both have muscle back or both have cavity back.

The first and second portions 54, 56 size, shape, location, etc. may be configured to optimize location of the clubhead 16 center of gravity for improved golf shot performance, e.g., lower score, straighter shot, longer shot, ball flight trajectory, etc.

The face thickness (see thickness 48 in FIG. 1) of the clubhead 16 between the striking surface 20 and the back surface 24 may be substantially same thickness between the first back portion 54 and the second back portion 56 in a single club from the sole to the topline. The thickness of the clubhead 16 between the striking surface 20 (see FIG. 1) and the back surface 24 may be substantially different thickness between the first back portion 54 (see FIG. 2) and the second back portion 56 (see FIG. 2) in a single club with the first back portion 54 or the second back portion 56 being thicker than the other portion. In FIG. 1, e.g., the face thickness towards the topline 22 is thinner than the face thickness towards the sole 26.

An angle 58 between the sole 26 and the center line 28 of the shaft 12 is known as the lie of the golf club 10. The range of the lie angle in a set of golf clubs is usually from the mid-50 degrees to the mid-60 degrees. In iron-type clubs, the range of lie angles is typically from about 59-60 degrees to about 63-64 degrees, but more or less is possible. Long iron-type clubs, i.e., lower lofted irons, have lower lie angles. Short iron-type clubs, i.e., higher lofted irons, have higher lie angles. Lower lie angles are more "flat" than higher lie angles, which are "up" or "upright" in comparison to the lower lie angles.

FIG. 3 shows in the bottom view that the clubhead 16 may have an indicia 58. In FIG. 3, the indicia is shown on the sole 26 of the clubhead 16, but the indicia 58 can appear elsewhere on the clubhead. This bottom view provides an opportunity to show offset in a golf club. Offset 60 is the distance that the forward, or striking surface 20, side of the hosel 18 of the clubhead 16 is set in front of the leading edge of the clubhead, which is disposed between the sole 26 and the striking surface 20 of the clubhead.

On an iron-type club, the indicia is traditionally a number, such as "1 ", "2", "3", "4", "5", "6", "7", "8", and "9", with a lower number associated with the longer iron having a longer shaft and lower loft, and a higher number associated with the shorter iron having a shorter shaft and a higher loft. Some sets of iron clubs can include "P" club which stands for pitching wedge, "A" club which stands for approach wedge, "G" club which stands for gap wedge, "S" club which stands for sand wedge, and "L" club which stands for lob wedge. However, these wedges found in sets of iron clubs generally have the same visual look and weight distribution of the lower lofted iron-type clubs with cavity back design, etc., and these wedges are not optimized for performance in the scoring range through weight distribution, etc.

Other indicia are possible to denote one iron-type club from another. Such indicia can include nontraditional indicia. The nontraditional indicia may include loft number for a scoring club (e.g., "41°" or "41") or an iron-type golf club (e.g, "33°" or "33"), for example. Further, the nontraditional indicia may include a predicted distance that a golfer will hit a golf ball with the golf club, e.g., " 149 yards" or "149". In addition, the nontraditional indicia may include a predicted distance range that a golfer will hit a golf ball with the golf club, e.g., "147 yards to 151 yards" or "147-151 ". In other words, the nontraditional indicia move away from the arbitrary traditional numbering or naming system of golf clubs towards what the golf club actually is, such as a 38° loft golf club or a 125 yard golf club. The nontraditional indicia may be used alone or in combination with the traditional indicia.

The set of iron clubs may consist of a plurality of iron-type clubs, or a combination of hybrid-type clubs for the lower loft clubs and iron-type clubs for the higher loft clubs. The number of golf clubs in a set of iron clubs can vary, with 6 to 8 clubs being the most typical. Each club in a set of irons has a different loft, with 3, 4 or 5 degree difference in loft being typical between consecutive clubs. These loft differences are typically smaller in the lower lofted clubs than in the higher lofted clubs, which serves to make the actual distance differences experienced by the golfer to be smaller at the lower-loft end of the set than at the higher-loft end of the set, which may not be conducive to delivering the distance precision desired in scoring range. Lower lofted clubs are progressively longer than the higher lofted clubs in a set. Table 1 shows information for an exemplary set of irons that includes 8 irons. The values, or characteristics, presented for the set of irons is merely provided for example and is not limiting. Other values are possible. Table 1. Set of irons.

Club No. Loft⁰ Lie° Length

3 18° 60° 39.5"

4 20° 60.25° 39.25"

5 23° 61 ° 38.5"

6 26° 61.75° 37.75"

7 30° 62.5° 37"

8 34.5° 63° 36.5"

9 39° 63.5° 36"

P 44° 64° 35.5"

Golfers as a whole have probably not improved in the past few decades, because the recorded handicaps of golfers has not improved measurably. 60-75% of the shots taken by a golfer during an 18 hole round of golf will be typically played within 9 iron distance of the green and hole that the golfer can strike a golf ball, regardless of the golfer's handicap. The scoring range may be the distance from the hole (also known as pin or flag) where the play of the golfer most acutely determines whether the golfer breaks par, or shoots 80, 90 or 100 on a regulation course with par set at about 70-72. "Scoring clubs" represent a new category of golf clubs. The set of scoring clubs may be crucial to helping the golfer achieve the golfer's scoring goals. The ideal set of scoring clubs may be different for each golfer depending on the golfer's skill level and the loft, length, and other specifications of the higher-lofted irons in the golfer's set of irons.

A set of scoring clubs may include a plurality of scoring clubs. The set of scoring clubs may include the three to six or more highest lofted clubs in the set of golf clubs that the golfer uses during a round of golf under the Rules of Golf. More generally the set of scoring clubs may include 2 or more of the highest lofted clubs in the set of golf clubs. The weight distribution and face thickness of each scoring club in the set of scoring clubs is adapted for the loft of each scoring club, such that the golfer can strike the golf ball with an optimal trajectory for precision distance control from slow through fast swing speeds.

The set of scoring clubs may be blended with the set of irons, which the golfer already owns or will own. The golfer may substitute one or more of the scoring clubs in the set of scoring clubs for one or more of the irons in the set of irons. For instance, the golfer may remove the 9 iron and pitching wedge from the golfer's regulation set of 14 clubs "in the bag" of a regulation set of golf clubs and substitute 2 scoring clubs and add 2 or 3 more additional higher lofted scoring clubs.

There is no industry-standard for loft, lie, shaft length, etc. for each club in a set of irons. A loft, lie, shaft length, and etc. can be provided for each scoring club in order to blend each of the scoring clubs into a set of scoring clubs that blend seamlessly with the golfer's set of irons. For instance, one golfer's set of irons may have a 38° loft 8 iron. The golfer would like 5° gaps between the golfer's scoring clubs and the 8 iron. For this golfer, the set of scoring clubs might include clubs with lofts at 43°, 48°, 53°, and 58°. On the other hand, another golfer's set of irons may have a 39° loft 8 iron. This golfer would like 4° gaps between the golfer's scoring clubs and the 8 iron. For this other golfer, the set of scoring clubs might include clubs with lofts at 43°, 47°, 51°, 55° and 59°. Of course, other combinations of degree gap differences, number of scoring clubs, etc. are contemplated. For example, the lofts and other characteristics of each of the scoring clubs may be selected by the golfer based on a performance characteristic, e.g., an estimated distance that the golfer will be able to strike the golf ball with the full swing (i.e., fast swing) or partial swing (i.e., slow swing) of one or more of the scoring clubs.

Each scoring club for the set of scoring clubs may be selected from clubheads with a variety of loft options with bounce features that allow the scoring clubs to function in specialty situations, such as sand and deep rough, and at slow through fast swing speeds.

FIG. 4 shows an exemplary embodiment with scoring clubs made with different lofts, weight distributions, etc. that may be used to create the plurality of scoring clubs. In an exemplary embodiment, a design theme could apply to the scoring clubs that may have a 3° loft difference from the next adjacent, in terms of degree, specific design. This approximately 3° loft difference is exemplary and not limiting.

The 3° loft difference may provide more accurate weight or mass distribution, etc. on the scoring clubs delivered to the golfer. By using a design theme with 3° loft difference between specific designs, the weight distribution, sole configuration, and the associated bounce of the sole may be more precisely controlled. By precisely controlling the weight distribution, the sole configuration and the associated bounce of the sole, the weighting and center of gravity for the clubhead may be more precisely controlled.

Of course, a design theme can be created that has a different specific design for each desired loft, such as each 1 °. Loft intervals of more or less than substantially 3° loft intervals may be used for each specific design. The desired lofts may be other than integer values, and the loft intervals may be other than integer values. The loft intervals may be successively of the same size or different.

In either approach to the design theme, as loft decreases from the highest loft in the range of lofts, the distribution of the mass progressively moves towards the topline and the heel and toe areas in order to optimize ball flight, distance control, and spread the mass around the projected impact area of the clubhead with the golf ball for consistent shot results.

The scoring clubs can be made by a suitable casting, forging or other technique. The loft of the clubs in the plurality of scoring clubs may range continuously from substantially 41° to substantially 61° with each loft in substantially 1° increments represented in the range. The range of scoring clubs may include loft values greater than 61°. Or the range of scoring clubs may include loft values lower than 41 °. Increments other than substantially 1° may be used.

The progressive weighting design applied to the scoring clubs may be extended downward to the rest of the lower-lofted iron-type clubs, and even into the hybrid-type clubs to produce a full matched set of approach clubs for any golfer. The lower-lofted clubs may be included in this concept so that one or more different design themes are presented to allow golfers of various skill levels to choose or be prescribed the lower lofted clubs best-suited their particular skill level.

The range of values may be discontinuous. The plurality of scoring clubs may not be represented in a continuous fashion. For instance, if no golfer ever selects a 49° scoring club, then the maker of the scoring clubs may optimize production and not produce, or create the ability to produce, the 49° scoring club. Each scoring club may show the indicia on the golf club, typically on the golf clubhead, denoted in one degree increments as shown in FIG. 4. The degree indicia may be the nearest integer degree loft of the clubhead. Of course, other indicia and loft increments may be utilized. For instance, the maker of the golf clubhead may elect to mark the scoring clubs in half degree increments. Or indicia may be used such that "A" represents 41°, "B" represents 42°, etc. Or indicia may be used such that "D" represents 41°, "V" represents 42°, etc.

A set of loft choices 62 (e.g., "41 ", "42", "43", "44", "45", "46", "47", "48", "49", "50", "51", "52", "53", "54", "55", "56", "57", "58", "59", "60", and "61") may be provided to the golfer, but this selection is not limited to the numbers included in this example. In FIG. 4, Golfer #1 has selected or may be prescribed scoring clubs with lofts of 43°, 48°, 53°, and 58°, Golfer #2 has selected scoring clubs with lofts of 43°, 47°, 51°, 55°, and 59°, and Golfer #3 has selected scoring clubs with lofts of 42°, 43°, 51 °, 56°, and 60°.

Each golfer may select or may be prescribed scoring clubs from the plurality of scoring club options that meets the needs and preferences of the golfer. The golfer may select scoring clubs or all the approach clubs based on gaps in loft between clubs, gaps in distance between estimated distance the scoring clubs will be hit, etc. Each individual golfer may make different selections of scoring clubs. As shown herein below, the selection process may be aided by a computer- implemented method for selection of the set of scoring clubs. The computer- implemented method may offer one or more options of the set of scoring clubs that the golfer may select. The selection process may include the golfer going to an establishment, such as a retail store, where the golfer interacts with someone in the retail store to select the scoring clubs for the golfer.

The set of scoring clubs may be designed to provide at least 1 or more clubs that substitute for one or more iron-type golf clubs (such as 9 iron, pitching wedge, etc.) in a second set of correlated golf clubs (such as a set of irons) with a seamless transition in shaft weight, material and flex, and in loft differentials, etc. Between the set of correlated scoring clubs and the second set of correlated golf clubs. This seamless transition may aided by choosing for the correlated set of scoring clubs one of a plurality of shafts that blend with the shaft weight and flex of the second set of correlated golf clubs, rather than using the industry standard "wedge" flex often used by manufacturers for wedges. For example, the shaft of the second set of correlated golf clubs may be regular weight steel, lightweight steel, regular weight graphite, lightweight graphite, etc.

The Rules of Golf currently permits 14 different clubs to be used by the golfer during a regulation round of golf. In one embodiment, at least 3 scoring clubs may be selected from the plurality of scoring clubs to create the set of correlated scoring clubs for use in the set of clubs compliant with the Rules of Golf. In another embodiment, at least 4 scoring clubs may be selected from the plurality of scoring clubs to create the set of correlated scoring clubs for use in the set of clubs compliant with the Rules of Golf. In another embodiment, at least 5 scoring clubs may be selected from the plurality of scoring clubs to create the set of correlated scoring clubs for use in the set of clubs compliant with the Rules of Golf. In another embodiment, at least 6 scoring clubs may be selected from the plurality of scoring clubs to create the set of correlated scoring clubs for use in the set of clubs compliant with the Rules of Golf. In another embodiment, any number of scoring clubs may be selected from the plurality of scoring clubs to create the set of correlated scoring clubs for use in the set of clubs compliant with the Rules of Golf.

One of the scoring clubs in the set of correlated scoring clubs may have the highest loft in the set of clubs compliant with the Rules of Golf.

FIG. 5 provides a flow chart for a MAKING SET OF CORRELATED SCORING CLUBS routine 100 illustrative of various steps that may be carried out in accordance with the foregoing discussion.

At step 102, one of the plurality of tools with the desired loft, weight distribution, etc. is selected to make a clubhead.

At step 104, the desired clubhead is manufactured using the tool. The clubhead may be manufactured by casting, forging, or other suitable technique.

At step 106, the manufactured clubhead, within tolerances, is attached to a selected shaft. Typically, manufacturing tolerances will provide the loft of the clubhead within 2° of the tool of the indicia. However, other tolerances may be used.

At step 108, the loft of the clubhead is measured. At step 1 10, the loft of the clubhead is adjusted, as needed, to match the indicia of the clubhead. The indicia of the clubhead may be added to the clubhead at any convenient point during the making of the set of correlated scoring clubs, by any suitable technique known to one skilled in the art, such as engraving, inserting, etc. Further, the lie of the clubhead may be measured and adjusted. The process is repeated until each of the desired scoring clubs has been made.

The steps may be added to, reordered or omitted, where appropriate.

Further steps of the MAKING SET OF CORRELATED SCORING CLUBS routine 100 may include making the tools, etc., which may be performed in a variety of sequences.

An example of the plurality of scoring clubs available through use of 7 tools is shown in table 2. The values, or characteristics, of the scoring clubs are presented by way of example and are not limiting. Other values are possible. Again, more or less than 7 tools may be used in the production of the plurality of scoring clubs.

Table 2. Plurality of scoring clubs.

Specifications:

Short Irons 41-43° 63° 0.075" 18° 4° 36" D3

Pitching 44-46° 63° 0.075" 18° 4° 35.75" D3

Wedges 47-49° 63° 0.075" 18° 4° 35.75" D3

Gap Wedges 50-52° 63° 0.05" 20° 5° 35.5" D3

Sand 53-55° 63° 0.035" 25° 5° 35.25" D4

Wedges 56-58° 63° 0.035" 30° 7° 35.25" D5

Lob Wedge 59-61 ° 63° 0.035" 35° 6° 35" D5

An example of shaft options is illustrated in table 3. The values, or

characteristics, of the shafts are presented by way of example and are not limiting. Other values are possible

Table 3. Shaft options. Shaft Specifications / Availability

GENIUS 12 KBS Steel 120 g Regular, Firm, Firm+ GENIUS 10 KBS Steel 90 g Regular, Firm, Firm+ GENIUS 9 UST Graphite 100 g Regular, Firm, Firm+ GENIUS 7 UST Graphite 75 g A(Senior/Women/Junior), Regular Now that how to make and use a scoring club or a set of scoring clubs has been disclosed, a golf club fitting or prescribing system and method will be disclosed. In the regulation set of golf clubs there may be several sets of different type golf clubs, as previously discussed hereinabove. The different subtypes of golf clubs can create abrupt transitions in distance, ball flight performance, etc. within the regulation set of golf clubs. Therefore, the golf club fitting system and method may help to create a seamless transition between the various sets or selections of golf club types in the regulation set of golf clubs that may be helpful. For example, a seamless transition between a set or selection of iron-type clubs and a set or selection of scoring clubs could be beneficial to the golfer.

Of course, the golf club fitting system and method can be used to ease transitions between other sets or selections of golf clubs such as between hybrid- type clubs and iron-type clubs, hybrid-type golf clubs and wood-type clubs, etc. So, while the discussion hereinbelow will be considered in terms of scoring clubs and iron-type clubs, but it will be understood that such is not limiting and is merely offered as a concrete example.

FIG. 6 shows a network based, dynamic fitted club (such as, scoring club) type fitting system 200 constructed and operated in accordance with various embodiments to promote a seamless transition from a set of fitted club type to a set or selection of first club (such as, iron-type club) type. The system 200 includes a number of components including a network accessible device 202 and one or more servers 204. The device 202 and server(s) 204 communicate over a network 206, such as a wide area network (WAN), a local area network (LAN), a broadband wireless network, Bluetooth, etc. alternatively, the device and server functions may reside in one location, such as a retail store or application for a smart phone or tablet device.

The network accessible device 202 can take a variety of forms, including but not limited to a desktop computer, laptop computer, a tablet, a smart phone or some other portable network accessible appliance adapted to download and execute applications. The device 202 is shown to include a controller 208, local memory (mem) 210 and a graphical user interface (GUI) 212. Other components may be incorporated into the device.

The controller 208 may be a hardware based or programmable processor that provides top level control of the device responsive to inputs supplied by a user of the device via the GUI 212. The device memory 210 stores information input by the user, programming and/or control information utilized by the controller 208, and information transferred to the device over the network 206.

The GUI 212 may include a keyboard, keypad, mouse, monitor, touch screen, touch pad, microphone, game controller, and/or other suitable components to enable human comprehensible interaction with and/or control of the device. It is contemplated although not necessarily required that the execution of a downloaded application from the memory 210 can be executed by user interaction with the GUI 212, and the resulting execution of the mobile app will display interactive audiovisual (also known as A/V) content on the GUI.

The server 204 can take a variety of forms, and is shown in FIG. 6 to include a controller 214, server memory (mem) 216, an applications (apps) manager 218, a set of fitted club type database manager 220, a set of first club type database manager 222, and an optional set of second club type database manager 224. Of course, more than 2 club type database managers are contemplated. Any number of club type database managers may be used, or one database may contain information for more than one club type. It will be appreciated that the managers 220, 222, 224 may be realized in hardware, software and/or firmware, and may reside on the same server or on distinct servers each having associated controllers and memory spaces to facilitate intercommunication via the network 206. Thus, while only a single network accessible device 202 and a single server 204 are shown in FIG. 1 , it will be appreciated that any number of respective devices and servers can be interconnected and utilized in accordance with the present disclosure. Of course, the functions of the device and server(s) could even reside in one physical apparatus.

As explained hereinbelow, a user of the device 202 can access the server(s) 204 to download an application from the apps manager 218 to the local device memory 210. During subsequent execution of the application, the set of fitted club type database manager 220, the set of first club type database manager 222, and the optional set of second club type database manager 224 are responsive to requests for such by the application.

FIG. 7 shows an input screen 230 in accordance with various embodiments. The user, typically the golfer for whom the fitted club type are fitted, will input information about the golfer's current set of first club type, and if the golfer has any clubs of a second club type (such as, wedges), the golfer's current selection of the second club type. The information may be input by free-text, pull-down menu, etc. For example, the brand and model for some sets of first club type may fully define the set of irons, but custom features may be input, again by free-text, pull- down menu, etc. Examples of custom features may include shaft type (e.g., regular weight steel, lightweight steel, regular weight graphite, lightweight graphite, shaft brand), shaft flex (e.g., A, Regular, Firm, Firm+), shaft length (e.g., +1 ", +3/4", +1/2", +/1/4", normal, -1/4", -1/2", -3/4", -1 "), clubhead lie (e.g., 3° up, 2° up, 1° up, normal, 1 ° flat, 2° flat, 3° flat), clubhead loft (e.g., weak 1 °, normal, strong 1°), grip size (e.g., undersize, normal, etc.). Custom features may be input for the golfer's current set of the second club type. One or more of the golfer's typical full-shot distances for the golfer's current set of the first club type, current set of second club type, or both may be input so that the fitting system can provide predicted distances for each club in the set of fitted club type on an output screen.

In other words, a first set of characteristics for a first golf club type are input, or a first set of characteristics for a set of first club type is input. An optional second set of characteristics for a second golf club type may be input, or an optional second set of characteristics for a set of second club type may be input.

FIG. 8 illustrates an output screen 240 in accordance with various embodiments. The output screen 240 may have one, two, three (shown), or more suggestions for a set of fitted clubs that are a "prescription" for the player to use in a desirable range for the fitted clubs, which may be the estimated distance that player can hit the golf ball with the fitted clubs in the set of fitted clubs. The number of suggestions may be responsive to an output slot size, such as a suitable pixel size or number of suggestions desired. The suggestions (such as "Suggestion 1", "Suggestion 2", "Suggestion 3", etc.) can be scaled, as needed, for display in the output screen.

The suggestion information may include a number of the fitted clubs (such as three), loft angles for each of the fitted clubs, lie angles for each the fitted clubs, shaft lengths for each of the fitted clubs, shaft type for each of the fitted clubs, shaft flex for each of the fitted clubs, etc. The output information may include such things as the estimated distance that the player will hit a golf ball with each of the fitted clubs on normal, strong or weak ball strikes. The distances can be calculated using any formula known to one skilled in the art, as the user can input a distance with loft and shaft length for the set of clubs that are already used. This information can be used to create the estimated distances for the fitted clubs. In other words, a fitted set of characteristics for a fitted golf club is determined to achieve an estimated result, or a fitted set of characteristics for a fitted set of golf clubs are determined to achieve estimated results. The estimated result(s) may be the estimated distance(s) that the golfer can hit the golf ball with the fitted golf club or the fitted set of golf clubs.

At least one of the fitted clubs can be selected by the user, such that selecting the set of fitted clubs is responsive to request by the user for at least one fitted club within the set of fitted clubs.

At least one of the fitted clubs in the set of fitted clubs can be made after the user has selected the set of fitted clubs.

FIG. 9 illustrates an exemplary database 250 for the set of first type of clubs used in the golf club fitting system and method. The set of second type of clubs may have a similar database. Or the database may be incorporated with the database for the first type of clubs, such as the database may contain information both iron-type and wedge-type golf clubs. The set of first type of clubs can include an arbitrary identification 252. The database information can include the make (e.g., manufacturer) 254 and model (e.g., manufacture part name or number) 256 of the first type of clubs. Manufacturing year 258 may be important information as club specifications can change from year to year for the same make and model club. A plurality of clubs 260 can be entered for each make, model, and year, hence the set of first type of clubs for each make, model, and year.

The club information can further include name designation, such as 7 iron (7i), 8 iron (8i), 9 iron, pitching wedge (PW), gap wedge (GW), sand wedge (SW), lob wedge (LW), etc. The club information can further include loft, shaft length, lie, etc. Not all club information may be needed, or entered, for each club. For example, the clubs that are at or near transition between the set of first type of clubs and the set of fitted clubs may require more information so that the transition can be as seamless as possible, whereas clubs further away from this transition point may not need as much information included in the database. While the clubs in the first type of clubs near the transition region may be needed for seamless transition, the other clubs in the set of the first type of clubs may still provide useful information such as distance, etc. that can be used to inform how the set of first type of clubs is seamlessly blended with the set of fitted clubs.

Any N number of sets of clubs may be entered into the database 250. The custom fitting process of the set of fitted clubs optimizes performance of the golfer in the range for which it may be desirable for a golfer to use the set of fitted clubs. The performance may be optimized according to shot accuracy, shot distance, strokes taken on the golf hole, etc.

However, the golf club fitting system and method is not limited to just seamlessly adding one set of golf clubs to another set of golf clubs in the regulation set of golf clubs. The golf club fitting system and method can be used with the regulation set of golf clubs that the golfer already possesses. We will disclose how this may be done.

FIG. 10 illustrates some of the dynamic swing parameters 270 within the control of the golfer that can affect distance, ball flight, etc. for a golf ball struck by the golfer. Tempo 272 is the rhythm of the golfer's swing of the golf club. Swing speed 274 is how fast the golf club is traveling at impact with the golf ball during the golf swing. Face angle 276 is the angle of the clubhead in relation to the swing path of the golf club at impact with the golf ball during the golf swing.

Angle of attack 278 is the angle of the clubhead in relation to the ground at impact with the golf ball during the golf swing, assuming the ground is relatively flat. In the golf swing with a positive angle of attack, the clubhead is ascending away from the ground when the clubhead strikes the golf ball. Alternatively, in the golf swing with a negative angle of attack, the clubhead is descending towards the ground when the clubhead strikes the golf ball. Other dynamic swing parameters 280 can include dynamic loft, club path, clubhead acceleration, swing plane from address to all impact, etc., Of course, this short list of dynamic swing parameters is not limiting but only provided by way of concrete example. Any appropriate dynamic swing parameter, club parameter, static parameter or other information associated with the golf swing, golf club, golfer performance, etc. can be incorporated into the fitting or prescription system and method.

In addition, the golf club characteristics can affect distance, ball flight, etc. for a golf ball struck by the golfer. For example, the golf club with the longer shaft can be used to achieve higher swing speed by increasing the arc of the swing. In addition, the loft of the clubhead can work in conjunction with the angle of attack to produce a "dynamic" loft of the clubhead. The dynamic swing parameters 270 can be monitored and recorded by a number of dynamic swing parameter devices readily available to golfers, e.g., SwingSmart golf swing analyzer by NewSpin Golf LLC and SwingTIP Golf Swing Analyzer and Training Tool by SwingTIP, Swingbyte 2 golf swing analyzer by Swingbyte, among many others. Whereas these dynamic swing parameter devices represent a new area of technology, it is contemplated that the capabilities of these devices will evolve quickly in the future, and those improvements and advances in technology can and will be incorporated into future iterations of the process described in this disclosure. The dynamic swing parameter device can be incorporated and made permanent to the golf club or may be readily detachable to be used on a variety of different golf clubs. In the consumer market, detachable devices that are transferable between clubs may be abundant and more desirable.

One skilled in the art would understand that by the golfer providing the distance that the golfer can strike a golf ball with a given club of known loft, lie shaft length, etc. an estimated swing speed might be calculated by a variety of similar formulas. By collecting estimated swing speeds for one or more golf clubs throughout the set of regulation golf clubs that the golfer uses, one might be able to determine the estimated distance that the golfer would hit the golf ball with a variety of different golf clubs having with different shaft length, lie, loft, etc.

By having the golfer use the dynamic swing parameter device, one can objectively acquire the swing speed information but also other information that can be used to determine the optimum golf clubs that the golfer should use. For example, by providing the golfer with one or more test clubs with shaft length, lie, loft, grip, etc. different than the golfer's own clubs, one can determine a more optimal regulation set of golf clubs that the golfer should use.

The dynamic swing parameter device can be provided to the golfer by a golf club manufacturer, an online retailer, a storefront retailer, etc. Or the golfer could purchase the dynamic swing parameter device for themselves.

By using the dynamic swing parameter device some of the less reliable factors can be reduced in the golf club fitting system and method. For example, golfers are notorious for believing that they hit the ball much farther than they actually do. By generating more objective data, the fitting process can be improved. In addition, the concept of the scoring zone may be increased beyond the distances of 100 yards or so, the 8 iron or higher loft, etc. With more accurate information and an improved selection of properly fitted and designed clubs, the golfer may learn to trust that their scoring zone really is 160 yards, 180 yards, or even well above 200 yards. In other words, they may develop a greater understanding of what their comfort zone for scoring is. By using this scoring zone, or comfort zone, that is tailored to the specific game of each golfer, the golf club fitting system and method can tailor a more particularized golf club prescription that meets the needs of the particular golfer.

For example, every golfer is going to carry a putter. Almost every golfer will carry a driver, which is the ultimate distance club. Between the putter and the driver, a variety of clubs are currently used in a regulation set of golf clubs. These clubs include wood-type clubs, hybrid-type clubs, iron-type clubs, and wedge-type clubs. As can be seen hereinabove, these clubs can also include scoring clubs.

By defining scoring club more broadly to encompass every distance at which a particular golfer has a realistic chance of getting the ball on or near the green if not in or near the golf hole, one can see that the scoring club and scoring range will differ for each golfer. And the range may extend well beyond 100 yards or extend to lower lofts than roughly a modern 9 iron.

In the power game, the golfer uses a full swing to strike the golf ball a reliable distance based on various golf club and dynamic swing parameters. By providing the golfer with golf clubs that have different characteristics and measuring the resulting changes in the dynamic swing parameters with a dynamic swing parameter device, information can be generated that can be input to the golf club fitting system and apparatus that provides a more particularized prescription for the golfer being studied. Not only can an optimum set of regulation golf clubs be observed through testing, but an optimum set of regulation golf clubs can be predicted for the golfer based on these studies.

In particular, this power game information, perhaps in combination with the golfer's own self-assessment on how comfortable they feel with hitting the golf ball close to the green, carryover a body of water, etc. can be used to prescribe the regulation set of golf clubs for the golfer. There is some lower limit to how far each golfer will hit the golfer's highest loft golf club. By way of concrete example, suppose that distance is 50 yards. Suppose that the other end of the spectrum the golfer is observed, based on measurements recorded with the dynamic swing parameter device, to have a scoring zone to 150 yards. The golfer could then be prescribed golf clubs between the golfer's putter and driver clubs that will be estimated to reliably give the golfer gaps between golf clubs from 50 yards up through 160 yards. Notice that if the golfer is prescribed a set of clubs with 10 yard gaps that only results in 1 1 clubs from 50 through 160 yards. The golfer would be prescribed clubs for 50 yards, 60 yards, 70 yards, 80 yards, 90 yards, 100 yards, 1 10 yards, 120 yards, 130 yards, 140 yards, and 150 yards. These 1 1 clubs in combination with the putter and driver result in just 13 clubs. In other words, the golf club fitting system and method could lead to a prescription for the golfer to carry less than the regulation set of golf clubs.

On the other hand, a long hitter may have a scoring zone out to 240 yards with the shortest distance for the golfer's highest lofted club being 60 yards. The gaps between clubs for this long hitter would be over 15 yards per club, if the golfer is still to carry a putter and driver.

The consistent yardage gap between clubs is not meant to be limiting but has only been provided as a concrete example.

Rather than having consistent, or substantially similar, yardage gaps between golf clubs, the golfer may choose or the prescription may suggest gaps that vary depending on the yardage the ball is being hit. For example, some golfers may elect to have shorter yardage gaps in their higher lofted clubs as they may wish more precision with these shorter higher lofted clubs that are typically used closer to the golf hole. On the other hand, larger yardage gaps between the lower- lofted golf clubs, which are typically used further from the golf hole, may not be as important as the golfer may feel less likely to be able to put the ball close to the golf hole even with narrower gaps.

However other variability in the yardage gaps between clubs could be contemplated. For example, the upper range of the prescription clubs may be 240 yards with the lower range 78 yards, but the golfer's home course has a number of long par 3's in the 200 to 240 yard range. In this situation, the golfer may actually elect to choose clubs that will give the golfer for more clubs selections at specific distances in the 200 to 240 yard range. Of course, the golfer could be fit or prescribed more than a regulation set of golf clubs so that the golfer can pick and choose which distance clubs to use during any particular round of golf.

Any variability and pattern of difference in yardage gaps between clubs in the fitting or prescribing program are contemplated.

A variety of different golf clubs can be used by the golfer to fill the golfer's prescription determined by the golf club fitting system and method. The method may determine that the golfer's current set of golf clubs can be modified through changing shaft length, lie, loft, etc. to better match the gaps that the golfer needs in the golfer's set of golf clubs used to play golf. In addition, it may be determined that another set of golf clubs should be seamlessly integrated into the golfer's current set of golf clubs. Of course, if the golfer already had a regulation set of 14 golf clubs, then some of the clubs would need to be substituted for by the new golf clubs. Alternatively, the golfer may elect to have more than 14 golf clubs available depending on particular preference and style of play that may vary depending on course, golfer skill level, etc. In some golfers may actually not care about the rules of golf and wish to exceed the limit of 14.

In addition, the scoring club described hereinabove could be extended down into the lower loft ranges such as down into the golf clubs with loft in the teens. Each club could have appropriate weight adjustments for generating proper ball flight characteristics, distance, etc. The scoring clubs in this range may include hybrid, hybrid-iron combination iron-type club, etc. heads extending from lower loft through higher loft.

FIG. 1 1 provides a flow chart on how the golf club fitting method might work to incorporate golf club characteristics and dynamic swing parameter measurements in accordance with some embodiments. The steps can occur in any appropriate order. The different steps may be optional.

At step 300, the method begins. At step 302, the golfer takes a swing while using a dynamic swing parameter device to record various dynamic swing parameters. At step 304, the golfer decides whether to try swinging a golf club again or stopping because enough information has been collected, the golfer is tired, etc. If the golfer has elected to swing again, at step 306, the golfer determines whether to use the same club or change to another club. If the golfer, elects to change clubs, then the golfer selects a new club for testing at step 308. Whether the golfers chooses to swing the same or different club, the golfer returns to step 302 to take a swing while using the dynamic swing parameter device to record various dynamic swing parameters.

If the golfer has elected to not swing again, then the dynamic swing parameter information from the golf club can be used to generate the dynamic swing parameter information used to start the fitting process at step 310. Of course, information can be provided to the golf club fitting system and method over time and it does not need to all be transmitted at once. The fitting system uses the golfer's dynamic swing parameter information in association with the golf clubs used and information about that golfer's particularized scoring zone to determine how to prescribe the golf clubs between the longest distance and the lowest distance that the golfer will hit a golf ball with full swing. The information collected can be transmitted directly from the dynamic swing parameter device, the dynamic swing parameter device to a portable device such as smart phone, etc. to another device as needed.

Of course, the prescription fitting method might be carried out on the portable device or in the dynamic swing parameter device itself if enough processing power, database information, etc. was available.

At step 312, the fitting method will access a database of golf clubs to determine what golf clubs would best fit the prescription that has been determined for the golfer. This prescription may include prescription of the golfer's own clubs, new or replacement clubs, or some combination of the golfer's current clubs and new or replacement clubs.

There may not be a set of golf clubs that matches the prescription needs of the particular golfer without some modification. In this case, the set of available clubs, which can include golf clubs of the golfer already has, and other available clubs, can be adjusted in the prescription to have different lie, loft, length, etc. at step 3 14. The method ends at step 316 with the golfer having a prescription for a set of golf clubs that meets the golfer's own particularized needs.

FIG. 12 provides another flow chart on how the golf club fitting method might work to incorporate golf club characteristics and dynamic swing parameter measurements in a computer-implemented method in accordance with some embodiments. The steps can occur in any appropriate order. The different steps may be optional.

At step 320, the method begins. At step 322, identification for at least one club of a golfer is acquired in a first memory from a network accessible device.

Again, the network accessible device can be any network accessible device, such as but not limited to, desktop computer, smart phone, tablet, etc. The identification for the at least one golf club can be placed in the first memory. The first memory, as with other memory, can be any suitable electronic memory, whether volatile, non-volatile, etc.

At step 324, specifications for the at least one golf club are selected from a first database of available golf clubs in a second memory responsive to the identification of the at least one golf club. The golfer is not limited to providing information for just one golf club. Many golfers may choose to use a set of golf clubs of one make and model. The initial set of golf clubs of the golfer may include a plurality of golf clubs that includes an iron-type club, and the at least one of the initial set of golf clubs replaced in the golfers set of clubs through the method has a loft of approximately 41° to approximately 45°.

By knowing any one golf club in the set of golf clubs, one may be able to deduce the other golf clubs in the set of golf clubs. For example, the golfer may use new model golf clubs from ABC Co. By providing information about new model ABC Co. 8 iron, the other clubs in the "iron set" may be discerned. In this way, the specifications for the at least one golf club may be selected responsive to the identification of the at least one golf club provided by the golfer. Of course, someone other than the golfer themselves may provide information, such as friend, neighbor, salesperson, etc., in this and other steps.

The first database of available golf clubs may include one golf club type or many golf club types. For example, the first database of available golf clubs may consist of iron-type golf clubs. On the other hand, the first database of available golf clubs may include sets of golf clubs of the wood-type golf club, hybrid-type golf club, iron-type golf club, wedge-type golf club, or any other suitable type golf club or any combination of same. At step 326, at least one suggestion for a set of golf clubs are rendered from a second database of available golf clubs in a third memory responsive to the specifications for the at least one golf club. The set of golf clubs suggested may typically be 4-6 golf clubs, however more or fewer golf clubs may be suggested. One golf club would not typically be suggested, as a set of golf clubs can be considered to be 2 or more golf clubs.

The first database of available golf clubs and the second database of available golf clubs may be different. For example, the first database of available golf clubs may be iron sets from a variety of manufacturers, while the second database of available golf clubs may be a set of scoring clubs that are intended to blend seamlessly with the iron sets. In this case, the at least one suggestion for a set of golf clubs would be made up of the scoring clubs.

On the other hand, the first database of available golf clubs and the second database of available golf clubs may be the same. For example, the golfer may use the at least one golf club that is identified for the selection process. However, the golfer may wish to use other clubs than the golfer currently owns or has access to in the golfer's set of regulation golf clubs compliant under the Rules of Golf. The golfer may wish to change the loft gap between the golfer's clubs. The golfer may wish to change the type of sole on the golfer's golf clubs. Any number of possibilities may exist for the golfer to change a certain subset of the overall set of golf clubs used by the golfer.

The first database of available golf clubs may include wood-type golf club, hybrid-type golf club, iron-type golf club, wedge-type golf club, or other suitable type golf club or any combination of same. The second database of available golf clubs may include wood-type golf club, hybrid-type golf club, iron-type golf club, wedge-type golf club, or other suitable type golf club or any combination of same. Again, the first database of available golf clubs and the second database of available golf clubs may be the same or different.

At step 328, the at least one suggestion is transferred for display in a graphical user interface (GUI) output slot of the network accessible device. In review, the process may include acquiring identification of the at least one golf club (step 322), selecting specifications responsive to the identification (step 324), rendering at least one suggestion responsive to the specifications (step 326), and transferring the at least one suggestion for display (step 328). At step 330, the method ends. However, there may be additional optional steps in the process.

The identification for the at least one golf club may include a make and model. The make can identify the manufacturer, such as SCOR Golf, Titleist, Callaway, Mizuno, etc. The model identification would be model names or numbers, such as 4161, MX-300, etc. (The make and model information may be trademark name of their respective owners.) The make and the model information can be used to populate the first and second databases of available golf clubs with specifications regarding loft, lie angle, shaft length, etc.

The specifications for a given make and the model may stay the same from year to year or may change. If the specifications for a given make and model of golf club change from year to year, then obtaining the manufacture year or model year of the at least one golf club can be important. Therefore, this information would need to be obtained in order to facilitate selection of the specifications from the first database of available golf clubs.

In addition, the specifications for the make and the model of golf club in the first and second databases of available golf clubs are based on factory standards. The identification for the at least one golf club may include a modification status of the at least one golf club from a set of standard

specifications of the at least one golf club for the make and the model. Concretely speaking, but not by way of limitation, if the at least one golf club has a shaft length that is ½ inch longer and the lie angle is 2° more upright from standard specifications, then this modification information is needed so that it can be incorporated into rendering at least one suggestion for a set of golf clubs. For example, the shaft length, lie angle or both of one or more of the golf clubs in the rendered at least one suggestion for the set of golf clubs may be modified from standard specifications. This modification information is needed so that the suggested set of golf clubs can blend seamlessly with golf clubs that the golfer already owns. This seamless integration of the suggested golf clubs with the golfer's own golf clubs may improve the overall performance of the golfer on the golf course.

While it is expected that the golfer will be able to provide the make and the model for the at least one golf club, and where appropriate year and modification status, that may not always be the case. For example, there is a developing industry of custom-made golf clubs. These custom-made golf clubs may be made by professional club makers or may be made by the nonprofessional using grips, shafts, and clubheads purchased as components. In this situation, there may be no good information on the make and the model so that the specifications can be selected. In this case, the golfer may need to provide the specifications for the at least one golf club that may include a loft, a lie angle, and a shaft length, among other specifications. These specifications may then be used to render at least one suggestion for a set of golf clubs responsive to the specifications.

At step 332, at least one performance characteristic of the golfer may be acquired. The at least one suggestion for a set of golf clubs may be rendered responsive to the at least one performance characteristic. For example, the at least one performance characteristic may be the distance a golf ball travels when the golf ball is struck with a first specified golf club by the golfer. In other words, the golf ball distance when the golf ball is struck with a first specified golf club by the golfer may be the at least one performance characteristic. The first specified golf club may be a golf club with a loft within the range of the lofts available from the second database of available golf clubs. Alternatively, the first specified golf club may be a golf club with a loft outside the range of lofts available from the second database of available golf clubs.

For example, the lofts within the range of lofts available from the second database of available golf clubs may be approximately 41° to approximately 61°. The specifications for the at least one golf club selected from the first database of available golf clubs shows that in a first instance the 8 iron has a loft of 38° and the 9 iron has a loft of 42°. The golf ball distance for the 8 iron, the 9 iron, or the combination of the 8 iron and the 9 iron may be used in rendering the at least one suggestion for a set of golf clubs. On the other hand, the specifications for the at least one golf club selected from the first database of available golf clubs shows that in a second instance, the 8 iron has a loft of 35°, the 9 iron has a loft of 39° and the pitching wedge has a loft of 43°. The golf ball distance for the 9 iron, the pitching wedge, or the combination of the 9 iron and the pitching wedge may be used in rendering the at least one suggestion for a set of golf clubs. In this second instance, the golf ball distance for the 8 iron may not be relevant for rendering the at least one suggestion for a set of golf clubs. These examples are meant to provide concrete examples and are not limiting.

A golf ball flight pattern when the golf ball is struck with a second specified golf club by the golfer may be the at least one performance characteristic. For instance, the golf ball flight pattern may be a push, slice, draw, hook, high flight, low flight, etc. The at least one performance characteristic may be used in rendering at least one suggestion for a set of golf clubs. For example, for the golfer that is fighting a slice, certain corrective measures that adjust the heel and toe weight, offset, etc. may be beneficial. Other possibilities are available.

A divot pattern when a third specified golf club is swung by the golfer may be the at least one performance characteristic. Besides the directional information that a divot can provide regarding whether the golfer is swinging the club down the target line, outside to inside swing path, or inside to outside swing path, the divot pattern may show that the golfer is a "digger" who strikes much turf and dirt on a swing or a "sweeper" who does not strike much, if any, turf or dirt on a swing. Of course, the divot pattern may show that the golfer is inconsistent with some digger and some sweeper swings.

The digger, sweeper, or inconsistent divot pattern may provide useful information for rendering at least one suggestion for the set of golf clubs from the second database of available golf clubs. For example, the sole of the golf club can be particularly important for the digger. The bounce characteristics of the sole may determine how easily the digger gets the clubhead through the ground and golf ball. This digger information made limit the clubs that may be most beneficial to the digger. On the other hand, the sweeper does not engage the ground on the golfer's typical swing. Therefore, the number of clubs that may be beneficial to the sweeper may be more expansive. The third specified golf club may be a wedge- type golf club, because wedge-type golf clubs typically have more bounce than other clubs, and the wedge type swing may more clearly show the distinctions between digger and sweeper type swings.

However, the specified golf club for the golf ball distance, the golf ball flight, and the divot pattern may be the same specified golf club, whether that club is 8 iron, 9 iron, pitching wedge, or some other club. At step 334, a set of dynamic swing parameters for the golfer may be acquired. The set of dynamic swing parameters are acquired by a dynamic swing parameter measurement device when the golfer swings a test golf club. The rendering the at least one suggestion for the set of golf clubs can be responsive to the set of dynamic swing parameters. As discussed above, the dynamic swing parameters can include tempo, swing speed, face angle, angle of attack, or other dynamic swing parameter that can be measured when the golfer is actually swinging the golf club.

Alternatively, a single dynamic swing parameter for the golfer may be acquired, and the at least one suggestion for the set of golf clubs can be responsive to the single dynamic swing parameter.

The rendering the at least one suggestion for the set of golf clubs can be responsive to the set of dynamic swing parameters acquired by a dynamic swing parameter measurement device when the golfer swings a test club with different golf club specifications than any of the golf clubs in the at least one suggestion of the set of golf clubs. Alternatively, the rendering the at least one suggestion for the set of golf clubs can be responsive to the single dynamic swing parameter acquired by a dynamic swing parameter measurement device when the golfer swings a test club with different golf club specifications than any of the golf clubs in the at least one suggestion of the set of golf clubs.

For example, the golfer could use the golfer's own golf club to swing using the dynamic swing parameter measurement device. The dynamic swing parameter information generated could be used to render the at least one suggestion for a set of golf clubs. The golfer's own golf club may not be included in the at least one suggestion for a set of golf clubs.

In another instance, the golfer may be sent a test club to use to determine the golfer's dynamic swing parameter information. The single parameter or set of parameters may be determined by the golfer swinging the test golf club that the golfer has been sent. This test golf club could be a regulation golf club fitted with a dynamic swing parameter measurement device, or the test golf club may be a specially fabricated golf club that is not a regulation golf club usable in a set of golf clubs compliant under the Rules of Golf. The specially fabricated golf club may have the dynamic swing parameter measurement device coupled through a module or integrated.

The at least one golf club may be one of a plurality of golf clubs. For example, the golfer may supply information on the 8 iron but based on the make and model one can determine that the iron set for the golfer runs from a 4 iron through gap wedge. At step 336, the at least one suggestion for the set of golf clubs may include at least one of the plurality of golf clubs is modified. The golfer golf clubs are the golf clubs that the golfer already owns or has access to for further use when starting the computer-implemented method. The golfer uses the plurality of golf clubs in accordance with the Rules of Golf. In order to match the plurality of golf clubs with the at least one suggestion for a set of golf clubs from the second database of available golf clubs, the at least one of the plurality of golf clubs is modified. For example, the at least one suggestion for the set of golf clubs includes 5 golf clubs. The set of clubs suggested may or may not place the golfer over the 14 club limit for the set of golf clubs compliant under the Rules of Golf. Adding 5 golf clubs to the golfer's bag could result in the golfer having over 14 clubs. In this situation, the golfer could be provided with at least one suggestion for the set of golf clubs that includes removing one of the golfer's golf clubs from the golfer's golf bag. Of course, a number of golf clubs in the at least one suggestion for the set of golf clubs could be different than 5.

For instance, it may be rendered that removing the 6 iron from the golf bag, wherein the 6 iron is approximately 30° loft, while adding 5 clubs with lofts of 41° and higher is a suggestion for the set of golf clubs. Removal of the 6 iron would create a yardage gap between the nominal 5 iron and the nominal 7 iron. Removal of the 6 iron could be considered a modification of the 6 iron as the 6 iron will no longer be used during a regulation round of golf. The 7 iron loft may be strengthened, which means decreased, and the 7 iron could be increased in length, as shaft length is correlated with golf ball distance. The 5 iron loft may be weakened, which means increased, and the 5 iron may be decreased in length. Or some combination of modifications through weakening the 5 iron, strengthening the 7 iron and adjusting shaft lengths of the 5 and 7 iron can smooth out the golf ball distance gaps in the set of golf clubs. FIG. 13 provides another flow chart on manufacturing the golf club in accordance with some embodiments. The steps can occur in any appropriate order. The different steps may be optional.

At step 340, the method begins. At step 342, a tool from a plurality of tools for manufacture of a clubhead is selected. The tool may be used in a forging, casting, or other manufacturing process. The tool may be engineered for manufacture of the clubhead with an engineered loft of approximately 3° different from an engineered loft of another tool in the plurality of tools. For example, the plurality of tools may include 7 tools with an engineered loft of approximately 42°, approximately 45°, approximately 48°, approximately 51°, approximately 54°, approximately 57°, and approximately 60°. This example is exemplary and not limiting.

In a set of clubs compliant under the Rules Of Golf, most golfers may prefer to have clubs that have at least a 3° difference in loft from any other club in the bag. In addition, most golfers use golf clubs that are nominally defined in integer lofts such as 41°, 42°, 43°, etc. Each tool may be used to manufacture the clubhead that is approximately 1° less than or 1° more than the engineered loft, in addition to using each tool to manufacture the clubhead with the manufactured loft. By setting the difference between in the engineered loft of the tools at

approximately 3°, the golfer can end up with the set of clubs in which each club in the bag is made from a different tool, such that each club is visually distinct to the golfer, although each club may fall within a visual theme of progressive change in back portion size, etc. Therefore, to the individual golfer it may appear that each club in the golfer's bag is made with an individual tool; however, the manufacturer can effectively produce a similar result of each club being visually distinct from any other club in the bag with one third the number of tools.

Another way of looking at the engineered lofts for the plurality of tools is that the first tool has an engineered loft X° and the second tool has an engineered loft (X+3)°, and each tool may provide one loft between X° and (X+3)°. As such, the first tool provides for the loft(X+l)°, and the second tool provides for the loft(X+2)°. At step 344, clubhead is manufactured using the tool by any suitable process such as casting, forging, and etc. These processes are well-known in the art and will not be discussed in detail here.

At step 346, a manufactured loft of the clubhead is measured. The manufactured loft may match the engineered loft; however, the manufactured loft is often different than the engineered loft due to issues that arise during the manufacturing process. The manufactured loft may be measured to be at the engineered loft, less loft in the engineered loft, or more loft than the engineered loft.

At 348, the manufactured loft is adjusted to a target loft. Of course, this adjustment step is optional. This adjustment step is not needed when the manufactured loft equals the target loft. The target loft can be within

approximately 1° of the engineered loft for the selected tool. At step 350, the method ends.

Further optional steps are possible. It is recognized that the clubhead may have an indicia that may be applied to the clubhead during any phase of the manufacturing process. The indicia may be used to identify the clubhead, such as the indicia "7" to identify the 7 iron or the indicia "48 to identify the 48° loft scoring club.

At step 352, the clubhead may be engraved with an indicia. The indicia corresponds to the target loft after manufacturing the clubhead. The clubhead may be engraved before or after measuring the manufactured loft, or even after adjusting to the target loft.

The indicia may be applied to the clubhead before measuring the manufactured loft. In this case, the loft would need to be adjusted to the target loft in the event that the manufactured loft does not match the indicia. One may apply the indicia to the clubhead before measuring the manufactured loft for the sake of efficiency. It may be simpler from an efficiency standpoint to apply a large number of indicia to a large number of clubheads and then measure.

The indicia may be applied to the clubhead after measuring the

manufactured loft. In this instance, the clubheads may be seen to have a variety of manufactured lofts due to the variability in manufacturing. One could envision that the manufactured lofts are measured and the golf clubs put into real or "virtual" bins that correspond to the manufactured loft that is measured. For example, the 51° tool that is used to generate 50°, 51 °, and 52° target lofts is found to have measured lofts that correspond to 50°, 51°, and 52° among other possibilities. The clubheads that are found to have manufactured lofts of approximately 50°, 51°, and 52° would not need adjustment.

At step 354, an indicia is inserted in a recess of the clubhead. The indicia corresponds to the target loft. The indicia may be coupled to the clubhead before or after measuring the manufactured loft, or even after adjusting to the target loft.

At step 356, a weight adjustment device is inserted in a weight port in the clubhead. The weight port may be substantially parallel to the long axis of the sole. The weight port may be substantially orthogonal to the long axis of the sole. The weight port may be substantially parallel to the striking face. The weight port may be in any other suitable orientation. The weight adjustment device may be used to address the golfer's individual performance characteristics, such as slice, etc. The weight adjustment device may be inserted before measuring the manufactured loft or after measuring the manufactured loft, or after the adjusting to the target loft.

At step 358, a retention plug is inserted in a recess on the clubhead. The retention plug may be inserted such that an exterior surface is substantially flush with an exterior surface of the clubhead. The retention plug may have an indicia that corresponds to the target loft. The insertion of the retention plug may facilitate retention of the weight adjustment device in the weight port. The retention plug may be inserted before measuring the manufactured loft or after measuring the manufactured loft or even after adjusting to the target loft.

It is contemplated that any logic sequence, artificial intelligence, programming techniques, and etc. can be used to implement the selecting, fitting, prescribing, etc. systems disclosed herein.

FIGS. 14-16 illustrate the golf club 10 with the clubhead 16 in accordance with various embodiments. FIG. 14 shows 1 club. FIG. 15 shows a series of 7 exemplary clubs in cross-section. FIG. 16 shows a series of 4 exemplary clubs focused on the back surface.

The back surface 24 may include a ridge portion 70 located between the upper back portion 54 and the lower back portion 56. The ridge portion 70 may form an obtuse angle in relation to the upper back portion 54, and the ridge portion 70 may form a convex angle in relation to the lower back portion 56, as seen in FIG. 15. The ridge portion 70 may be continuously bowed with convexity towards the topline 22, as shown in FIG 16.

The convexity may increase for each club at the loft successively lower in the range of loft for a set of clubs, as shown in FIGS. 16. Loft decreases in the direction of the arrow 72.The set of clubs may be a set of clubs compliant under the Rules of Golf that a golfer would use on a golf course, which typically means that consecutive clubs, other than the potter and driver, would have a loft within approximately 3° to approximately 6° of another club in the set. The set of clubs may include 3 clubs, 4 clubs, 5 clubs, 6 clubs, 7 clubs, 8 clubs, 9 clubs, 10 clubs, 1 1 clubs, or 12 clubs. For example, in a set of golf clubs with lofts of 53°, 49°, and 45°, the 53° club has less convexity towards the topline 22 than the 49° club and the 49° club has less convexity towards the topline 22 than the 45° club. In the alternative view, the 45° club may have increased convexity towards the topline 22 in relation to the 49° club, and the 49° club may have increased convexity towards the topline 22 in relation to the 53° club. For the example, in other words, the convexity may increase for each golf club at the loft successively lower in the range of lofts for the at least 3 golf clubs.

The lower back portion 56 may encircle a depression 74 that is continuously curvilinear with the depression 74 concave in relation to the lower back portion 56, which may be best seen in FIG. 15. The depression 74 may not be rectangular. The continuously curvilinear depression 74 may continuously increase in size as the loft decreases for each successive golf club in the range of lofts for a set of clubs compliant under the Rules of Golf that a golfer would use on a golf course. The set of clubs may include 3 clubs, 4 clubs, 5 clubs, 6 clubs, 7 clubs, 8 clubs, 9 clubs, 10 clubs, 1 1 clubs, or 12 clubs. For the example, the continuously curvilinear depression 74 may continuously increase in size as the loft decreases for each successive golf club in the range of lofts for the at least 3 golf clubs.

By varying size of the depression 74, the mass apportionment for each club in the set of golf clubs may be distributed to the heel, or true, the sole, and the topline as needed to manage golf ball distance, golf ball flight trajectory, etc. when the golfer strikes the golf ball with the golf club. It is possible that the

apportionment of the mass progresses to the point where the lower back portion 56 is congruent with substantially all of the back surface 24, such that the upper back portion 54 is substantially absent. This congruence is more likely to happen, if at all, in the clubs with lower lofts. In other words, the lower back portion 56 may increase in proportion to the back surface 24 as the loft decreases.

The continuously curvilinear depression 74 may have a depth 76 that is concave in relation to the lower back portion 56. The depth 76 may be greater in the club with lower loft in a set of clubs compliant under the Rules of Golf that a golfer would use on golf course. The set of clubs may include 3 clubs, 4 clubs, 5 clubs, 6 clubs, 7 clubs, 8 clubs, 9 clubs, 10 clubs, 1 1 clubs, or 12 clubs. For example, in a set of golf clubs with lofts of 53°, 49°, and 45°, the 45° club may have increased depth 76 in relation to the 49° club, and the 49° club may have increased depth 76 in relation to the 53° club. For example, in other words, the continuously curvilinear depression may continuously increase in size as the loft decreases for each successive golf club in the range of lofts for the at least 3 golf clubs.

In some golf clubs, the depression 74 for mass redistribution may be absent. In this situation, the depth 76 is by definition absent. When the depression 74 is absent, the lower back portion 56 may have a surface that is substantially flat, as seen in FIG. 15 regarding (X+18)°. The lower back portion 56 may be flat in one or more of the highest lofted clubs in a set of golf clubs. In FIG. 15, X° corresponds to 42°, but that is merely exemplary and not limiting. Similarly, the 18° range and 7 clubs in the series of clubs shown in FIG. 15 are exemplary and not limiting.

The continuously curvilinear depression 74 may be oblong with a long axis 78 and a short axis 80. The long axis 78 may be longer in the club with lower loft in a set of golf clubs compliant under the Rules of Golf that a golfer would use on a golf course. The set of clubs may include 3 clubs, 4 clubs, 5 clubs, 6 clubs, 7 clubs, 8 clubs, 9 clubs, 10 clubs, 1 1 clubs, or 12 clubs. For example, the long axis 78 of the at least 3 golf clubs with a lower loft may be longer than the long axis 78 of the at least 3 golf clubs with a higher loft. The long axis 78 may be substantially parallel to the sole 26.

The continuously curvilinear depression 74 may be oblong with the long axis 78 and the short axis 80. The short axis 80 may be longer in the club with lower loft and a set of golf clubs compliant under the Rules of Golf that a golfer would use on a golf course. The set of clubs may include 3 clubs, 4 clubs, 5 clubs, 6 clubs, 7 clubs, 8 clubs, 9 clubs, 10 clubs, 1 1 clubs, or 12 clubs. For example, the short axis 80 of the at least 3 golf clubs with a lower loft is longer than the short axis 80 of the at least 3 golf clubs with a higher loft. The short axis 80 may be substantially orthogonal to the sole 26.

The lower back portion 56 may encircle an oblong depression 74 that is concave in relation to the lower back portion 56. The oblong depression 74 may be larger in the club with lower loft and a set of golf clubs compliant under the Rules of Golf that a golfer would use on a golf course. The set of clubs may include 3 clubs, 4 clubs, 5 clubs, 6 clubs, 7 clubs, 8 clubs, 9 clubs, 10 clubs, 1 1 clubs, or 12 clubs. For example, the oblong depression 74 may be larger in the at least 3 golf clubs of lower loft than in the at least 3 golf clubs of higher loft.

In some embodiments, the set of correlated golf clubs may include a plurality of golf clubs. Each golf club includes a sole 26 opposite a topline 22, a toe 50 opposite a heel 52, and a striking face 20 opposite a back surface 24. The back surface 24 has an upper back portion 54 located closer to the topline 22 than to the sole 26. The back surface 24 has a lower back portion 56 located closer to the sole 26 than to the topline 22. Each golf club has a first thickness 82 between a substantial entirety of the upper back portion 54 and the striking face 20 that is uniform in thickness. Each golf club has a second thickness 84 between a substantial entirety of the lower back portion 56 and the striking face 20 that is non-uniform in thickness. The first thickness 82 may be less than the second thickness 84.

However, in some clubs towards the lower range of lofts some portion of the second thickness 84 between the lower back portion 56 and the striking face 20 could be less that and the first thickness 82. This would be due to the depth 76 increasing size.

Each golf club has a loft and a mass. The plurality of golf clubs can include any number of golf clubs greater than one. Typically, the plurality of golf clubs will include at least 3 golf clubs. In the plurality of golf clubs, the mass is distributed continuously and progressively more towards the sole 26, the topline 22, the toe 50, and the heel 52 for each golf club at the loft consecutively and successively lower in a range of lofts for the set of golf clubs compliant under the Rules of Golf.

As shown in FIG. 14, a logo 98 may appear on the back surface 24. The logo 98 may provide the make (e.g., "Company X"), the model (e.g., "Super Duper Club"), a slogan (e.g., "Inspiring Words"), etc. In respect to the back surface 24, the logo 98 may be raised, depressed, or some combination of raised and depressed. The logo 98 may wholly reside in the upper back portion 54, the lower back portion 56, or some combination of the upper back portion 54 and the lower back portion 56. The logo 98 may wholly reside in the depression 74, or the logo 98 may reside in whole or in part outside the depression 74 on the back surface 24.

When the logo 98 is substantially similar on each of the clubs in a set of golf clubs, then the logo 98 in and of itself may not serve to apportion mass progressively more towards the topline 22, the sole 26, the toe 50 and the heel 52. When the logo 98 does not serve to apportion mass differently between different clubs in the set of golf clubs, the logo 98 is not considered to be the depression 74.

A set of correlated golf clubs may generally include a plurality of golf clubs. Each golf club in the plurality of golf clubs may have a distinct mass distribution that creates a distinctive visual appearance to a golfer. Each successively lower lofted golf club has a redistribution of mass towards a sole, a topline, a toe, and a heel to optimize ball flight characteristics for each individual successively lower lofted golf club. In other words, each individual golf club in a set of golf clubs is not formed from one visual design, wherein the one visual design might be used to produce a set of up to eight or nine iron-type golf clubs, for example. Rather, each individual golf club in the set of golf clubs may be designed with the performance characteristics that may benefit the golf performance of the individual golfer, based on that individual golfer's dynamic swing parameters, past performance, golfer preference, etc. While each individual golf club in the set of golf clubs may be individually designed, which may lead to the golf clubs being visually distinctive to the golfer, the set of golf clubs may have a design theme that may be achieved by gradual transitions in mass around the club at each successive loft in the set of golf clubs. The design theme reinforces for the golfer that the golf clubs are a correlated set of golf clubs. FIG. 17 shows insertion of an indicia 86 into the clubhead 16. The indicia 86 may be inserted into a recess 88 of the clubhead 1 . The indicia 86 may correspond to the target loft. The indicia 86 may be coupled to the clubhead 16 before measuring the manufactured loft. Alternatively, the indicia 86 may be coupled to the clubhead after measuring the manufactured loft. In other words, the indicia 86 may be inserted into the clubhead 16 at any point during the making of the clubhead 16. The indicia 86 is shown flush with the sole 26, however the indicia 86 may appear on any portion of the clubhead 16. The indicia 86 may be held in place by any suitable means known to one skilled in the art, such as mechanical fastener (e.g., screw, nail, rivet, bolt, etc.), epoxy, etc. The indicia 86 may be made of any suitable material, such as steel alloy (e.g., carbon steel or stainless steel), polymer, etc.

A weight adjustment device 90 may be inserted in a weight port 92 in the clubhead 16. A retention plug 94 may be inserted in a recess 96 on the clubhead 16. The retention plug 94 may be held in place by any suitable means known to one skilled in the art, such as mechanical fastener (e.g., screw, nail, rivet, bolt, etc.), epoxy, etc. The retention plug 94 may have an indicia that corresponds to the target loft. Insertion of the retention plug 94 may facilitate retention of the weight adjustment device 90 in the weight port 92. The weight port 92 is shown substantially orthogonal in its long axis to the sole, however the weight port 92 may assume any orientation needed to facilitate optimizing the golfer's ball flight, distance, etc. The weight adjustment device 90 and the retention plug 94 may be added to the clubhead 16 at any point while the clubhead 16 is being made.

The weight adjustment device 90 and the retention plug may be made of any suitable material, such as steel alloy (e.g., carbon steel or stainless steel), polymer, etc. The material used for the weight adjustment device 90 and the retention plug 94 may be the same or different than the material used for the clubhead. The material used for the weight adjustment device 90 and the retention plug 94 may be the same or different from each other.

It is to be understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description, together with details of the structure and function of various embodiments of the invention, this detailed description is illustrative only, and changes may be made in detail, especially in matters of structure and arrangements of parts within the principles of the present invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Claims

Claims:

1. A set of correlated golf clubs comprising:

a plurality of golf clubs, wherein each golf club in the plurality of golf clubs has a distinct mass distribution that creates a distinctive visual appearance to a golfer, and each successively lower lofted golf club has a redistribution of mass towards a sole, a topline, a toe, and a heel to optimize ball flight characteristics for each individual successively lower lofted golf club.

2. The set of correlated golf clubs of claim 1, wherein each golf club in the plurality of golf clubs includes the sole opposite the topline, the toe opposite the heel, and a striking face opposite a back surface,

wherein the back surface has an upper back portion located closer to the topline than to the sole, and a lower back portion located closer to the sole than to the topline,

wherein a first thickness between a substantial entirety of the upper back portion and the striking face is uniform, and a second thickness between a substantial entirety of the lower back portion and the striking face is non-uniform,

wherein the lower back portion encircles a continuously curvilinear

depression that is concave in relation to the lower back portion, and wherein the continuously curvilinear depression is larger in each lower lofted golf club in the plurality of golf clubs in relation to the next higher loft golf club in the plurality of golf clubs.

3. The set of correlated golf clubs of claim 1 , wherein each golf club in the plurality of golf clubs has a nontraditional indicia for visual identification of the golf club.

4. The set of correlated golf clubs of claim 1, wherein the plurality of golf clubs comprises 3 golf clubs of successively progressive consecutive lofts in a set of golf clubs compliant under the Rules of Golf.

5. The set of correlated golf clubs of claim 1, wherein the plurality of golf clubs comprises 4 golf clubs of successively progressive consecutive lofts in a set of golf clubs compliant under the Rules of Golf.

6. The set of correlated golf clubs of claim 1, wherein the plurality of golf clubs comprises 5 golf clubs of successively progressive consecutive lofts in a set of golf clubs compliant under the Rules of Golf.

7. The set of correlated golf clubs of claim 1, wherein the plurality of golf clubs are all the golf clubs between a driver and a putter for the golfer in a set of golf clubs compliant under the Rules of Golf.

8. A set of correlated golf clubs comprising:

a plurality of golf clubs, wherein each golf club includes a sole opposite a topline, a toe opposite a heel, and a striking face opposite a back surface,

wherein the back surface has an upper back portion located closer to the topline than to the sole, and a lower back portion located closer to the sole than to the topline, wherein a first thickness between a substantial entirety of the upper back portion and the striking face is uniform, a second thickness between a substantial entirety of the lower back portion and the striking face is non-uniform, and the first thickness is less than the second thickness, and

wherein each golf club has a loft and a mass, and

wherein the plurality of golf clubs includes at least 3 golf clubs, and the mass is distributed continuously and progressively more towards the sole, the topline, the toe, and the heel for each golf club at the loft consecutively and successively lower in a range of lofts for the at least 3 golf clubs compliant under the Rules of Golf.

9. The set of correlated golf clubs of claim 8, wherein the back surface further comprises a ridge portion located between the upper back portion and the lower back portion, the ridge portion is continuously bowed with convexity towards the topline, and the convexity increases for each golf club at the loft successively lower in the range of lofts for the at least 3 golf clubs.

10. The set of correlated golf clubs of claim 8, wherein the lower back portion encircles a continuously curvilinear depression that is concave in relation to the lower back portion, and the continuously curvilinear depression continuously increases in size as the loft decreases for each successive golf club in the range of lofts for the at least 3 golf clubs.

1 1. The set of correlated golf clubs of claim 10, wherein the continuously curvilinear depression has a depth that is concave in relation to the lower back portion, and the depth of the at least 3 golf clubs with a lower loft is greater than the depth of the at least 3 golf clubs with a higher loft.

12. The set of correlated golf clubs of claim 10, wherein the continuously curvilinear depression is oblong with a long axis and a short axis, and the long axis of the at least 3 golf clubs with a lower loft is longer than the long axis of the at least 3 golf clubs with a higher loft.

13. The set of correlated golf clubs of claim 10, wherein the continuously curvilinear depression is oblong with a long axis and a short axis, and the short axis of the at least 3 golf clubs with a lower loft is longer than the short axis of the at least 3 golf clubs with a higher loft.

14. The set of correlated golf clubs of claim 8, wherein the lower back portion encircles an oblong depression that is concave in relation to the lower back portion, and the oblong depression is larger in the at least 3 golf clubs of lower loft than in the at least 3 golf clubs of higher loft.

15. A computer-implemented method compr acquiring identification for at least one golf club of a golfer in a first memory from a network accessible device;

selecting specifications for the at least one golf club from a first database of available golf clubs in a second memory responsive to the identification of the at least one golf club;

rendering at least one suggestion for a set of golf clubs from a second

database of available golf clubs in a third memory responsive to the specifications for the at least one golf club; and

transferring the at least one suggestion for display in a graphical user

interface (GUI) output slot of the network accessible device.

16. The computer-implemented method of claim 15, wherein the identification for the at least one golf club comprises:

a make; and

a model.

17. The computer-implemented method of claim 16, wherein the identification for the at least one golf club further comprises:

a modification status of the at least one golf club from a set of standard specifications of the at least one golf club for the make and the model.

18. The computer-implemented method of claim 15, wherein the specifications for the at least one golf club comprises:

a loft; and

a lie angle; and

a shaft length.

19. The computer-implemented method of claim 15, further comprising: acquiring at least one performance characteristic of the golfer, wherein the rendering at least one suggestion for a set of golf clubs is responsive to the at least one performance characteristic.

20. The computer-implemented method of claim 19, wherein the at least one performance characteristic is selected from the group consisting of a golf ball distance when the golf ball is struck with a first specified golf club by the golfer, a golf ball flight pattern when the golf ball is struck with a second specified golf club by the golfer, and a divot pattern when a third specified golf club is swung by the golfer.

21. The computer-implemented method of claim 15, further comprising: acquiring a set of dynamic swing parameters for the golfer, wherein the set of dynamic swing parameters are acquired by a dynamic swing parameter measurement device when the golfer swings a test golf club, and the rendering the at least one suggestion for the set of golf clubs is responsive to the set of dynamic swing parameters.

22. The computer-implemented method of claim 15, wherein the rendering the at least one suggestion for the set of golf clubs is responsive to a set of dynamic swing parameters acquired by a dynamic swing parameter measurement device when the golfer swings a test golf club with different golf club specifications than any of the golf clubs in the at least one suggestion for the set of golf clubs.

23. The computer-implemented method of claim 15, wherein the at least one suggestion for a set of golf clubs comprises a plurality of golf club types chosen from the group consisting of a wood-type golf club, hybrid-type golf club, iron-type golf club, and wedge-type golf club.

24. The computer-implemented method of claim 15, wherein the at least one golf club is one of a plurality of golfer golf clubs, and the at least one suggestion for the set of golf clubs further comprises:

modifying at least one of the plurality of golfer golf clubs, which the golfer uses in accordance with the rules of golf, in order to match the plurality of golfer golf clubs with the at least one suggestion for a set of golf clubs from the second database of available golf clubs.

25. A method comprising:

selecting a tool from a plurality of tools for manufacture of a clubhead, wherein the tool is engineered for manufacture of the clubhead with an engineered loft of approximately 3° different than an engineered loft of another tool in the plurality of tools;

manufacturing the clubhead using the selected tool;

measuring a manufactured loft of the clubhead; and

adjusting the manufactured loft to a target loft, wherein the target loft is within approximately 1° of the engineered loft for the selected tool.

26. The method of claim 25, further comprising:

applying an indicia to the clubhead, the indicia corresponding to the target loft.

27. The method of claim 25, further comprising:

engraving the clubhead with an indicia corresponding to the target loft after manufacturing the clubhead.

28. The method of claim 25, further comprising:

inserting an indicia in a recess on the clubhead, the indicia corresponding to the target loft, and the indicia is coupled to the clubhead before measuring the manufactured loft.

29. The method of claim 25, further comprising:

inserting an indicia in a recess on the clubhead, the indicia corresponding to the target loft, and the indicia is coupled to the clubhead after measuring the manufactured loft.

30. The method of claim 25, further comprising:

inserting a weight adjustment device in a weight port in the clubhead; inserting a retention plug in a recess on the clubhead, the retention plug having an indicia corresponding to the target loft, and insertion of the retention plug facilitates retention of the weight adjustment device in the weight port.