AU2021209276A1

AU2021209276A1 - Tennis let detection system with shot clock control

Info

Publication number: AU2021209276A1
Application number: AU2021209276A
Authority: AU
Inventors: Fredric Goldstein
Original assignee: Group One Ltd Great Britain
Current assignee: Group One Ltd Great Britain
Priority date: 2018-09-07
Filing date: 2021-07-29
Publication date: 2021-08-19
Anticipated expiration: 2039-09-06
Also published as: FR3085595B1; AU2021209276B2; GB202108883D0; GB2587846A; GB202008635D0; GB2587846B; GB2596418B; FR3141627A1; GB2596418A; FR3085595A1; AU2019226223A1

Abstract

A method of let detection with integrated shot clock control is disclosed comprising measuring a force associated with a net extending across a tennis court and indicating, using an indicator, whether the force meets or exceeds a 5 threshold force during a short duration using at least one of (1) a vibration force, (2) alight, and (3) a sound. The threshold force is indicative of an impact between a ball and the net. The method includes pressing a button on one of a handset and a tablet to arm a let detection function, and the indicating step is only performed when the let detection function has been armed. The method further 10 includes pressing a button on the handset, tablet or a further handset to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match. A system providing a handset with let detection and integrated shot clock control for use by an umpire is also disclosed. 15 FIG. 9 for publication 6/7 90 10 96 94 FIG.9

Description

6/7

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FIG.9

TENNIS LET DETECTION SYSTEM WITH SHOT CLOCK CONTROL

FIELD This disclosure relates to a system and method relating to tennis. In particular, a system is disclosed providing alet detection and integrated shot clock method and system for use by an umpire.

DEFINITION In the present description and claims, the term "comprising" shall be understood to have a broad meaning similar to the term "including" and will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. This definition also applies to variations on the term "comprising" such as "comprise" and "comprises".

Further in the present description and claims, the term "handset" shall be understood to encompass any device able to that is able to send and/or receive a signal wirelessly, e.g. by cable, e.g. to a router or controlling device. Further in the present description and claims, the term "base" shall be interpreted broadly and includes any device that is able to send a signal that the threshold force indicating a ball impact on the net has been met.

BACKGROUND The reference to prior art in the background above is not and should not be taken as an acknowledgment or any form of suggestion that the referenced prior art forms part of the common general knowledge in Australia or in any other country. On all tennis courts, perhaps the most notable part is the net. In one known example, a tennis net includes two main net posts placed at a pre determined height (e.g., 107 cm), and positioned a distance (e.g., 91.4 cm) outside the outermost (or doubles) sidelines of a tennis court. The net is typically composed of a woven or plastic netting supported by an upper net cable. The netting hangs from a strong metal cable via a white net tape. The net cable is attached to one post and then to the opposite post, which has a crank that winds the cable so that the net tightens and rises up to the required height and a desired tension. The current rules of tennis proscribes for a "service let," which is when during a first serve, the ball clips the net but still falls inside the service box. When a "let" is called, the first serve must be replayed. If the ball clips the net and does not fall in the service box, a "fault" called. The responsibility of calling out a "let" falls to the chair umpire. It will be appreciated that at service speeds of over 200 kph for professional tennis players that it can be difficult or impossible to see whether a ball has clipped the net. Let of net chord detection systems have been introduced that can detect when a ball impacts or hits a net and send a signal to the umpire. In order to avoid the detector from being activated during normal play the chair umpire must arm the detector prior to every service point. The chair umpire is also responsible for calling other code violations such as "foot faut", "fault" and out". These calls must be made essentially immediately, before the opposite player attempts to return the ball. The chair umpire also accurately record and announce the score. It will be appreciated that careful attention and quick response of the chair umpire is an essential (and often underappreciated) part of the game of tennis. This especially so for major international events with a worldwide audience and millions of dollars dependent upon the outcome. Another rule of tennis is that after announcement of the score, there is a 25 second time limit from the time the score is announced to when the next serve must be made. Failure to meet this time limit is a code violation that again must be called out and recorded by the umpire. The umpire has discretion before announcing the score, for example to allow an excited crowd to settle. The umpire is able to selectively start, pause, or resume the start clock. It will be appreciated that the job of an umpire requires great concentration in not only closely observing the field of play, but calling out code violations, recording and announcing the score, arming the let detection device an controlling the stop clock.

It would therefore be advantageous to provide an alternative let detection and integrated shot clock method and system for use by an umpire. The present disclosure also describes a net tension system and method. which holds the net down by coming over the top of the net and being fastened to a clasp on the playing surface. This provides greater tension than a crank could practically provide (by pulling down at the mid- point of the net), since cables generally will sag, and provides the defined low part of the net in the center, and at a determinable height, which is important during play. The result is a semi-V shape running along the top of the net, where the center strap provides the regulation 91.4 cm height of the net in the middle. In tennis tournaments throughout the world, each net can be set differently. Wimbledon is known for aloose net while the U.S. Open is known for a tight highly tensioned net. In fact, because both tournaments are outdoors, the net may be taken down as much as several times, on any particular day, due to inclement weather. From tournament to tournament, and court to court, and even from day to day, and hour to hour, the tension in a tennis net can vary and thus a precise, uniform net tension in tennis is lacking. With this varying net tension, comes varying net heights (as net height is directly correlated to net tension, as explained further below). When net tension is different, balls that clip the very top of the net ("net tape") during a rally will dribble over aloose net (resulting in what is called a cheap point), as a net with a looser tension absorbs the forward movement of the ball, allowing balls which hit the tape to roll over to the other side of the net. Conversely, with a tight net, the ball that clips the net tape will either sit up for an easy put away, or bounce out for a loss of the point, as tighter tensions do not absorb the forward pace and either send balls hitting the tape backward or cause the ball to change trajectory and fly out. This causes inconsistency in playing conditions. Additionally, as mentioned, when net tension is different, the height of the net will be different. This is despite the fact that the net post is a defined height, as is the centre-strap (107 cm and 91.4 cm respectively). The net traverses the court typically at 12.8 m in length (or 10.97 m for a singles net post). The net itself weighs approximately 10 kg (alternately approximately twice that for the ATP World Tour nets). Therefore, there will be a measurable sag in the net even when it is cranked up to reach the centre-strap 91.4 cm height. The more one cranks thereafter, the tighter the net, thus as the net tension increases, the sag between the net posts/singles sticks and the centre-strap will lessen, as the net cable will straighten out while being pulled tighter (resulting in different heights between those two points). This non-measured cranking (done essentially by "feel") can result in not only an inconsistent net tension but also an inconsistent net height. While the height of a net is the same for players on both sides, a player with more top spin will have an advantage over a player who hits a flatter ball when the net height can vary as much as several millimetres over the most of the playing area of the net (and as much as 1 cm at the midpoint between the singles stick and centre-strap where the sag is greatest). Further, players who prefer to hit down the line (as opposed to cross court) will have alower/higher net height at precisely that part of the net, with potentially different results of any such shot, depending upon the net tension. The court itself has strictly defined dimensions and measurements in millimetres, as determined by the tennis governing bodies, and should thus preferably define the height of the net at any given point by virtue of knowing (and creating) the net tension. For serves, the current rules call for a "service let," which is when the ball clips the net and still falls inside the service box. Loose nets will likely result in more lets while tight nets more likely cause the ball to either bounce back, sit up, or fly further and thus out (a "fault"). Professional tennis had recently considered removing the "service let." Should this still happen in the future, more "aces" will occur with loose nets (as the ball dribbles over to the other side) while tight nets will cause more balls to sit up for easy winners by the opponent or will go fly out for aloss of the point. The result is different depending upon the net tension. This is unacceptable, as the effect can be different on different courts and even change on the same court on the same day when the net often needs to be taken down on outdoor courts during rain, or to change nets during events with different tours (which have different nets). The result is an ever-varying net tension and height for virtually each time a net is set up. This is because the precise height of the net on either side of the center strap extending to the net posts (and thus a majority of the playing area) is dependent upon the net tension. Even if the tension is sufficient to pull the center strap up to its regulation 91.4cm (3ft) height, there remains a sag.

Further cranking of the net not only increases the net tension but also straightens up the sag, which raises the net in varying degrees along its length, with the largest increase in the middle of the net between the center strap and net posts where most balls pass, and the least amount occurring closer to either the center strap or the net post. At this midpoint, the height differential between a loose net and a tight net can result in up to a centimeter or more discrepancy. Applicant appreciates the benefit that would result from consistency in net tension across tennis because it would achieve a consistency in net height as well as net tension. Proving an umpire with an alternative method and system. As far as applicant is aware this is the first disclosure of a technology that achieves this significant working advantage in tennis and especially in professional tennis.

SUMMARY Aspects of this relate to a let detection and stop clock control method and system that may provide an umpire with an alternative method and system. According to a first aspect of this disclosure there is provided a method, comprising: measuring a force associated with a net extending across a tennis court; indicating, using an indicator, whether the force meets or exceeds a threshold force during a short duration using at least one of (1) a vibration force, (2) a light, and (3) a sound, the threshold force being indicative of an impact between a ball and the net; pressing a button on one of a handset and a tablet to arm a let detection function, wherein the indicating step is only performed when the let detection function has been armed; and pressing a button on one of: the handset; a further handset; and the tablet to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match. The step of pressing a button to control a shot clock may occur before the pressing a button to arm alet detection function. According to a second aspect there is disclosed a second method, comprising measuring a force associated with a net extending across a tennis court; indicating, using an indicator, whether the force meets or exceeds a threshold force during a short duration using at least one of (1) a vibration force, (2) a light, and (3) a sound, the threshold force being indicative of an impact between a ball and the net; pressing a button on one of a handset and a tablet to arm a let detection function, wherein the indicating step is only performed when the let detection function has been armed; and pressing a button included in the same one of: the handset; and the tablet to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match. The step of pressing the button in the above first and second methods may control the shot clock to help enforce a time limit imposed upon the player during a service game. The shot clock may be situated on the tennis court. Controlling the shot clock may include starting, stopping, pausing, or resuming the shot clock. In this case, when a button is pressed on the handset a signal is sent to the tablet to start, stop, pause, or resume the shot clock.

Alternatively, controlling the shot clock may include starting, stopping, pausing and resuming the shot clock. In this case, when a button is pressed on the handset a signal is sent to the tablet to start, stop, pause and resume the shot clock.

In the above first and second methods, the let detection function may be armed during the service game of the player and may not be armed during a rally of the tennis match such that the indicating step is not performed during the rally.

In the above first and second methods, the indicator may include a haptic feedback device, and the indicating step may include generating the vibration force with the haptic feedback device. The haptic feedback device may be incorporated into the handset.

In the above first and second methods, the indicator may include alight, and the indicating step includes illuminating the light. The indicating step may include illuminating the light in a first color when the threshold force has not been met or exceeded and further includes illuminating the light in a second color different than the first color when the threshold force has been met or exceeded. The indicator may also be an audio indicator, and the indicating step includes generating the sound when the threshold force has been met or exceeded. In the above first and second methods, the threshold force may be based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve. The above first and second methods may further comprise using a remote device or the further handset to detect when a chair umpire leaves his chair for a ball mark inspection; said remote device or further handset being placed on the person of the chair umpire, said remote device being wirelessly connected to the handset or tablet connected to the handset; said remote device being configured to send a signal to the handset when said remote device has detected the remote chair umpire has left his chair and descended down to a court; said handset sending a signal to the tablet; said tablet being connected to the internet and being configured to send a message to specified parties that the chair umpire has left his chair to make a ball mark inspection in order that said parties may take particular action, such as to suspend betting related to a match. In the above first and second methods, pressing the arming button may additionally indicate the next point has started. The above first and second methods may further comprise connecting pairing and connecting the remote device or further handset to the handset or tablet when the two are in close proximity. Still further disclosed is a method of a third aspect, the method, comprising using a detector to detect if there has been movement of a tennis net caused by the force of an impact between a ball and the net has occurred during a serve, pressing a button on one of a handset; a further handset; and a tablet to arm a let detection function, wherein the detection of movement is only performed when the let detection function has been armed; and pressing a button on the same one of: the handset; the further handset; and the tablet to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match. The step of pressing the button may control the shot clock to help enforce a time limit imposed upon the player during a service game. The shot clock may be situated on the tennis court. Controlling the shot clock may include starting, stopping, pausing, or resuming the shot clock. A button on the handset may be pressed on the handset which sends a signal to the tablet to start, stop, pause, or resume the shot clock.

Controlling the shot clock may include starting, stopping, pausing and resuming the shot clock. A button on the handset may be pressed which sends a signal to the tablet to start, stop, pause and resume the shot clock. The let detection function may be armed during the service game of the player and is not armed during a rally of the tennis match such that the indicating step is not performed during the rally. An indicator may be used to indicate when movement has been detected. The indicator may include a haptic feedback device, and the indicating step includes generating the vibration force with the haptic feedback device. The haptic feedback device may be incorporated into the handset. The indicator may include a light, that illuminates when movement has been detected. The indicator may an audio indicator, that generates sound when movement has been detected. Movement may be detected by measuring a force associated with a net extending across a tennis court, and wherein the indicating step occurs when the force meets or exceeds a threshold force during a short duration. The threshold force may be based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve. The step of pressing the button to arm the let detection function may include pressing a button on the handset and the step of pressing the button to control the shot clock may include pressing a button on the handset, and the handset includes the indicator. According to a fourth aspect there is disclosed a method using an indicator to indicate by one of a vibration force, alight or a sound, indicating that movement of a tennis net caused by the force of an impact between a ball and the net has occurred during a serve; pressing a button on one of a handset; a further handset; and a tablet to arm a let detection function, wherein the indicating step is only performed when the let detection function has been armed; and pressing a button on a different one of: the handset; the further handset; and the tablet to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match.

According to a fifth aspect there is disclosed a method comprising using an indicator to indicate by one of a vibration force, a light or a sound, indicating that movement of a tennis net caused by the force of an impact between a ball and the net has occurred during a serve; pressing a button on one of a handset; a further handset; and a tablet to arm a let detection function, wherein the indicating step is only performed when the let detection function has been armed; and pressing a button on the same one of: the handset; the further handset; and the tablet to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match. In the fourth or fifth methods, the step of pressing the button may control the shot clock to help enforce a time limit imposed upon the player during a service game. The shot clock may be situated on the tennis court. Controlling the shot clock may include starting, stopping, pausing, or resuming the shot clock. When a button is pressed on the handset a signal may be sent to the tablet to start, stop, pause, or resume the shot clock. Alternatively controlling the shot clock may include starting, stopping, pausing and resuming the shot clock. In this case, when a button is pressed on the handset a signal is sent to the tablet to start, stop, pause and resume the shot clock. In the fourth or fifth methods, the let detection function may be armed during the service game of the player and is not armed during a rally of the tennis match such that the indicating step is not performed during the rally. In the fourth or fifth methods, the indicator may include a haptic feedback device, and the indicating step includes generating the vibration force with the haptic feedback device. The haptic feedback device may be incorporated into the handset. Alternatively, the indicator may include a light, and the indicating step includes illuminating the light. Still further, the indicator may be an audio indicator, and the indicating step includes generating the sound. The fourth or fifth methods may further comprise measuring a force associated with a net extending across a tennis court, and wherein the indicating step occurs when the force meets or exceeds a threshold force during a short duration. The threshold force may be based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve. In the fourth or fifth methods, the step of pressing the button to arm the let detection function may include pressing a button on the handset, the step of pressing the button to control the shot clock may include pressing a button on the handset, and the handset includes the indicator. According to a sixth aspect there is disclosed a still further method, comprising indicating, using an indicator, that an impact between a ball and a tennis net has occurred; pressing a button on one of a handset and a tablet to arm a let detection function, wherein the indicating step is only performed when the let detection function has been armed; and pressing a button on one of the handset and the tablet to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match. The step of pressing the button may control the shot clock to help enforce a time limit imposed upon the player during a service game. The shot clock may be situated on a tennis court. Controlling the shot clock includes starting, stopping, pausing, or resuming the shot clock. The method may include pressing a button on the handset which sends a signal to the tablet to start, stop, pause, or resume the shot clock. Alternatively, the signal sent to the handset may include starting, stopping, pausing and resuming the shot clock. The let detection function may be armed during the service game of the player and is not armed during a rally of the tennis match such that the indicating step is not performed during the rally. The indicator may include a haptic feedback device, and the indicating step includes generating a vibration force with the haptic feedback device. The haptic feedback device may be incorporated into the handset. Alternatively, the indicator includes a light, and the indicating step includes illuminating the light. Still further, the indicator may be an audio indicator, and the indicating step includes generating a sound. The method may include measuring a force associated with a net extending across a tennis court, and the indicating step occurs when the force meets or exceeds a threshold force during a short duration. The threshold force may be based on a fingerprint, and the fingerprint may be a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve. The indicating step may occur following a perturbation of the tennis net. Perturbation of the tennis net may be detected by any suitable means such as a camera or laser. The step of pressing the button to arm the let detection function may including pressing a button on the handset, the step of pressing the button to control the shot clock may include pressing a button on the handset, and the handset may include the indicator. Also disclosed is a seventh method, comprising indicating, using an indicator, that an impact between a ball and a tennis net has occurred; pressing a button on one of a handset and a tablet to arm alet detection function, wherein the indicating step is only performed when the let detect. The step of actively controlling the shot clock may comprise detecting a predetermined sound above a threshold decibel level. The predetermined sound may be a voice of a chair umpire. The step of detecting the voice of the chair umpire may only occur within a predetermined time following completion of a point in a tennis match and the score has been electronically recorded by the chair umpire. A suitable time may be 7,6,5,4,3 or 2 seconds. The chair umpire records the score after a tennis point prior to announcing the point. That the voice activation of the shot clock may only occur after the score has been updated may prevent inadvertent control of the shot clock during play for example calling out a fault. The step of actively controlling the shot clock may also include using speech recognition. The step of using speech recognition to control the shot clock may include starting the shot clock after interpreting speech of a chair umpire as an announced score following completion of a point in a tennis match. Pressing the button may also generate a start of point signal indicating that a point in a match has started in response to the button being pressed, the shot clock may reset. In the seventh method, the shot clock may be remote from the handset and the tablet and is situated adjacent a tennis court.

The seventh method may further comprise measuring a force associated with a net extending across a tennis court, and the indicating step occurs when the force meets or exceeds a threshold force during a short duration. The threshold force may be based on a fingerprint and the fingerprint may be a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve. The indicating step may occur following a perturbation of the tennis net. Perturbation of the tennis net may be detected by any suitable means such as a camera or laser. The step of actively controlling the shot clock may include using a facial or hand gesture. Also disclosed herein is a first system comprising an indicator configured to express that an impact between a ball and a tennis net has occurred; and a computing system including a button which, when pressed, arms a let detection function, wherein the indicator is only operable when the let detection function is armed, and the computing system further includes a button which, when pressed, controls a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match. The computing system may include at least one of a handset and a tablet. The handset may include the button which, when pressed, sends a signal to the tablet to start, stop, pause, or resume the shot clock. Alternatively, the signal may be sent to start, pause and resume the shot clock. The button may be configured to arm the let detection function and the button configured to control the shot clock are on the handset. The handset may include the indicator. The shot clock may be situated on a tennis court. The indicator may include a haptic feedback device, a light, and an audio indicator. The indicator may be configured to express that the impact has occurred when a force associated with the net exceeds a threshold force during a short duration. The threshold force may be based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve.

The indicator may be configured to express that the impact has occurred following a perturbation of the tennis net. Also disclosed is a second system comprising a detector to detect if there has been movement of a tennis net due to the force of an impact of a tennis ball during a serve; a computing system including a button which, when pressed, arms a let detection function, wherein the detector is only operable when the let detection function is armed, and the computing system further includes a button which, when pressed, controls a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match. The computing system may include at least one of a handset and a tablet. The handset may include the button which, when pressed, sends a signal to the tablet to start, stop, pause, or resume the shot clock. The button configured to arm the let detection function and the button configured to control the shot clock may be on the handset. The handset may include the indicator. The shot clock is situated on a tennis court. The computing system may be at least partially mounted upon or adjacent to a chair of a chair umpire. The system may, comprising an indicator to indicate when movement of the net has been detected. The indicator may include a haptic feedback device, a light, or an audio indicator. The indicator may be configured to express that the impact has occurred when a force associated with the net exceeds a threshold force during a short duration. The threshold force may be based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve. The indicator is configured to express that the impact has occurred following a perturbation of the tennis net. Also disclosed is a third system comprising an indicator configured to express that an impact between a ball and a tennis net has occurred; and a computing system including a button which, when pressed, arms a let detection function, wherein the indicator is only operable when the let detection function is armed, and the computing system further includes a button which, when pressed, controls a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match. The computing system may include at least one of a handset and a tablet. The handset may include the button which, when pressed, sends a signal to the tablet to start, stop, pause, or resume the shot clock. The button may be configured to arm the let detection function and the button configured to control the shot clock are on the handset. The handset may include the indicator. In the third system, the shot clock may be situated on a tennis court. The computing system may be at least partially mounted upon or adjacent to a chair of a chair umpire. The indicator may include a haptic feedback device, a light, or an audio indicator. The indicator may be configured to express that the impact has occurred when a force associated with the net exceeds a threshold force during a short duration. The threshold force may be based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve. The indicator may be configured to express that the impact has occurred following a perturbation of the tennis net. Also disclosed is a fourth system comprising an indicator configured to express that an impact between a ball and a tennis net has occurred; and a button which, when pressed, arms a let detection function, wherein the indicator is only operable when the let detection function is armed; and an interface permitting a user to actively control of a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match, wherein the interface does not include a digital or physical button. A voice command device may be in communication with the microphone and is configured to generate a signal which starts the shot clock in response to a chair umpire speaking a score of a tennis match into the microphone following a point in the tennis match. The voice command device may be a tablet. A handset may be connected to the tablet. The button configured to arm the let detection function may be on the handset. The button may be configured to generate a start of point signal. In response to the button being pressed, the shot clock may be configured to reset.

The interface may also be a camera configured to acquire images indicative of a hand or facial gesture of a chair umpire. Alternatively, the interface may be a sensor screen on the handset or additional handset that triggers the shot clock by either a motion over the screen or by physically touching the screen In the fourth system, the indicator may be configured to express that the impact has occurred when a force associated with the net exceeds a threshold force during a short duration, and the threshold force is based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve. Aspects of the invention are set forth in the appended independent claims. Preferred and/or optional features of the invention are set forth in the appended dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to the other embodiments, unless such features are incompatible. Exemplary embodiments of the invention shall now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a view of an example net tension system. Figure 2 is a close-up view of the system of Figure 1. Figures 3A is a view of another example net tension system. Figure 3B is a view of yet another example net tension system. Figure 3C illustrate example pull scales for use in the system of Figures 1-3A. Figure 4 is a view of still another example net tension system. Figure 5 is a close-up view of the example net tension system of Figure 4. Figures 6A-6B show a further example net tension system.

Figure 7 shows a further example system. In Figure 7, a light is configured to become illuminated to indicate a let has occurred. Figure 8 shows a further example system. In Figure 8, a speaker is configured to make a relatively loud sound, such as a beep, to indicate a let has occurred. Figure 9 illustrates a chair umpire, an example handset, and an example tablet. Figure 10 is a close-up view of an example setup including an example handset and an example tablet. Figure 11 is a schematic plot of measured force versus time for a typical net cord. Figures 12A to 12E are schematic, close-up views of variants of Figure 11.

DETAILED DESCRIPTION Figure 1 illustrates an example net tension system 10. The system 10 is used in connection with a net 12, which spans a playing area 14 in a direction of its length L. The playing area 14 in one example is a tennis court, and the net 12 is a tennis net. This disclosure may be used outside of tennis, however. The net 12 is supported on opposite sides of the playing area 14 by net posts 16 (Figure 4). The net 12 includes an upper cable 18 (or, "net cable") supporting a mesh (or, netting) 20. The upper cable 18 spans the distance between the net posts 16. At least one of the net posts includes a crank (not shown) for adjusting the tension in the upper cable 18. This tension, in turn, tightens the net 12. For all intents and purposes, the term net tension describes the tightness of the net, and is directly related to the tension in the upper cable 18, as well as the force exerted by the net 12 on one or more connectors provided between the net 12 and the playing area 14 (such as the center-strap 22 and the singles stick 43). The net 12 is connected to the playing surface 14, in this example, by a center-strap. The upper cable 18 exerts an upward force F1 on the center-strap 22 in a direction substantially perpendicular to the length L of the net 12. This is because the net 12 is higher at each end (e.g., the net posts 16 are at 107 cm height) than in the middle, so the center-strap 22 necessarily pulls down upon the net 12, creating the upward force F1. The center-strap 22 resists the force F1 with an equal and opposite force to maintain the net 12 in a normal condition (the pre determined height of the center-strap 22). The force F1 is resisted by way of the center-strap 22 being connected to the playing surface 14. In one example, the center-strap 22 is connected to the playing surface by a cable 24 attached to a first connecting support 26, which is selectively attachable to a hook28. In one example of this disclosure, a scale 30 measures the force F1 exerted by the upper cable 18 on the center-strap. The force F1 is indicative of a tension in the net 12. That is, the higher the tension of the upper cable 18, the higher the force F1 against the center strap 22. As used herein, the term "scale" refers to any force measuring device, including, but not limited to pull scales 32A-32D (Figure 3A), compression scales, and load cells (such as tension load cells and tension meters). A system 10 solely for determining net tension would work with a standard scale, while a service let indicator (discussed below) may require a faster load cell to obtain speeds high enough to register a ball strike. In the example where the scale 30 is a load cell, such as an electronic load cell, the system 30 10 may include an amplifier/digitizer and other associated electronic components. The scale may be digital (as in pull scale 32D), or mechanical (e.g., spring-type, as in pull scales 32A-32C). As shown in Figure 3, the scale 30 may be attached to the center-strap 22 by a cable 24, which can be connected to the center-strap 22 via a second connecting support 34. The first connecting support 26 is connected to the playing surface 14 via the hook 28, which is typically built into tennis courts. If desired, an extension of the center-strap 22 can be attached via the first connecting support 26 to hang downwards and hide the scale 30. Alternatively, the color of the scale 30 may be selected to blend in with the net 12 or playing surface 14. The scale 30 may be connected to the center-strap 22 in other ways. As illustrated in Figure 2, the scale 30 may include an indicator 36 expressing the force F1 measured by the scale 30. In Figure 2, the indicator 36 includes a digital display 38 that graphically expresses the measured force as a numerical quantity. The indicator 36 of Figure 2 is attached to the scale 30. In other examples, such as in Figure 3A, the indicator 36 is provided separately from the scale 30. In Figure 3A, the indicator 36 may be selectively plugged into the scale 30, via cable 40, to obtain the force measurement. Alternatively, the indicator 36 may be in wireless communication with the scale 30. In one example, the indicator 36 is mounted near a chair umpire or other appropriate official for monitoring during the course of a tennis match. The indicator may include standard buttons, such as power, reset, etc. Because the tension of the net is directly correlated to the height of the net, this will alert the chair umpire (or other official) that, for example, the center-strap 22 has loosened (thus the tension will be lower), allowing the umpire to adjust it at an appropriate time during the match. While this disclosure extends to all types of indicators 36, the indicator 36 of Figure 3A may have the advantage of only being used during measurement, and not being exposed and vulnerable to damage during play. The indicator 36 of Figure 3A further takes up less space, and is not readily visible, compared to that of Figure 2. Moreover, since there are often several courts in any tennis club or professional tennis tournament, the (potentially) more expensive digital readout of the indicator 36 of Figure 3A need not be purchased for each and every pull scale 14, since the measuring of the force F1 can be done on several courts using the same indicator 36. Figure 3B shows a variation in which a scale is built into a standard latching found in most tennis center-straps 22. The result is a scale and latching combination that is not appreciably larger than any standard latching. In one example, a pull scale 44 is incorporated into the latching 42. The pull scale 44 may include a spring acting on pin 46, which is connected to the center-strap 22 via the second connecting support 34. The pin 46 is moveable is responsive to the force F1. The pin 46 is attached to an indicator 48 that moves relative to indicia 50. In on example, the indicia 50 corresponds to a preferred net tension. Other indicia may be present. Figure 3C shows three pull scales (e.g., 32A-32C) which are not electronic. While perhaps not as accurate or as easy to read, they have the potential advantage of greater durability, lower cost, and avoid the issue of batteries. These first three scales can be incorporated into this disclosure, should one desire a non electronic scale. The fourth scale 32D is an example of an off the shelf pocket size digital pull scale. As the upper cable 18 is adjusted, the force F1 will change, and, in turn, so will the height H of the net 12 (between the net post 18 or the singles stick 43, and the center-strap 22) and the overall tension in the upper cable 18. In one example, aloose net may indicate a force F1 of 4.5 kg while a tight net might show a force F1 of 5.8 kg (approximately 44 N and 57 N, respectively). The scale 30 can accurately measure the force F1. In the example of Figures 1-3B, the measurement is made at a point furthest away from the net posts 16 (e.g., at the center-strap), which may exhibit the least tension, and is also the part of the net 12 most in play. Thus, the force F1 exerted on the center-strap 22 at this point may provide the most useful information about the overall tension of the net 12. The measurement can be made with or without singles sticks 43 (Figure 4), as long as all measurements obtained are consistently. This is, in part, because any change in the angle of a taut upper cable 18 necessarily increases the tension, thus the singles sticks 43 may change the force F1 on the center-strap 22 (having created a more acute angle), and so measurements with/without the singles stick 43 will be markedly different. Because the placement of the singles sticks 43 must be exact, it may be preferred that the net tension is measured before the singles sticks 43 are placed, thus removing a possible variable. Further, when the upper cable 18 is cranked tighter, it moves slightly laterally and therefore may cause the singles sticks 43 to lose their exact vertical position. Turning to another embodiment, Figure 4 illustrates singles sticks 43 provided relative to the net 12. Singles sticks 43 may be used to provide a consistent measurement of the tension of the net 12. In this embodiment, a downward force F2 from the upper cable 18 of net 12 is measured. It will be understood that the downward force F2 exerted by the net 12 will vary depending on how far a particular point of measurement is from the net posts 16. A singles stick 43 is, by one example rule, positioned 91.4 cm from the sideline of a singles court. The height H of the net 12 at this point, by example, is 107 cm. As such, because the height and position of the singles stick 43 is precisely defined by the rules of tennis, it can be used to provide a uniform measurement to easily duplicate net tension. The downward force F2 that the upper cable 18 exerts on the singles sticks 43, in a direction substantially perpendicular to the length L of the net 12, will accurately reflect a tension of the net 12, since the arrangement of the singles stick 43 will be the generally be consistent. In one example, the singles stick 43 is connected to a scale 52 at its base. Seen in detail in Figure 5, this scale 52 can be built into the base of the singles stick 43 (as shown), built into the playing surface 14, or be a separate structure. The scale 52 may function substantially as described relative to the scale 30 of Figures 1-3B. For instance, the scale 52 may include an indicator 54 having a digital screen 56 for expressing the measured force F2. This screen 56 can be incorporated into the scale 52 or be separate and attached via a cable when measurements are made. While there are two singles sticks 43 commonly employed in tennis (one on each end of the net), only one stick is generally required to measure the net tension. Further, it will be appreciated that while a standard singles stick is placed 91.4 cm outside the singles sideline, one can also place the device at another point along the net. Further, because the presence of the center-strap 22 changes the net tension, the measurements taken at the singles sticks 43 will be markedly different if a center-strap 22 is not used, or if used, not at its regulation 91.4 cm height. Thus, the presence or absence of the center-10 strap 22 should be noted when measuring the force F2. Likewise, the presence or absence of the singles sticks 43 should be noted when measuring the force F1 at the center-strap, as discussed relative to Figures 1-3B. This will, again, lead to consistency in the net tension. Figure 6A shows a non-digital scale for measuring the force F2. In Figure 6A, a singles stick 43 has a first section 58 overlapping a second section 60. The first section 58 is moveable relative to the second section 60. A spring 62 is provided inside the first section 58, and generally resists the force F2 exerted on the singles stick 43 by way of the upper cable 18. Depending on the level of force F2, the spring 62 will compress a corresponding amount. In turn, the first section 58 will move relative to a second section 62. The first section 58 in this example includes a window 64 and an indicator 66 that slides relative to indicia 68 on the second section 62. Like in the above examples, the indicia 68 may correspond to a preferred net tension.

Turning to Figure 6B, a U-shaped guide 70 may optionally be attached to the first section 58. The U-shaped guide 70 supports the upper cable 18, and may be adjustable relative to the first section 58 via threads 72. The threads 72 also allow the height of the singles stick 43 to be adjusted to meet the required 107 cm, while also allowing the singles stick 43 to customize the net tension. Using any of the above embodiments, one can then duplicate a tension time and again. With no measurable variables, that is, the distance between the net posts (12.8 m), the inelasticity of the steel net cable, the height of the single post (107 cm), and the position of the singles stick (91.4 cm outside the single sideline), and the 91.4 cm height of the net at the center-strap, are all fixed by rule, the net tension will substantially be the exact same in each instance. This measurement can be used each time when putting a net up or can be used to simply test periodically that the net tension has remained the same. An additional benefit of the system 10 relates to the service let rule. A serve that clips the net 12 but still falls in the service box is called a "let" and is re-played. With the instant disclosure, any ball that comes into contact with the net 12 will change the force (e.g., F1 or F2) caused by tension of the net 12. Such a contact and the resulting change in the force will be picked up by the scale. That is, the contact between the ball and the net changes the force F1, F2 from a normal level to a threshold level indicating that there has been contact between the net 12 and the ball. The threshold force will be of an extremely short duration, and may create a unique "fingerprint" of a sharp spike (for example, a dip and/or peak). This unique combination of a particular frequency and amplitude (the angle and length of the dip/peak) forms the algorithm for when the threshold force is met, with the resulting audible signal (beep) or other notification means may be triggered, indicating a "let." The fingerprint associated with the threshold force will be different than the effect that wind might have. Essentially, the effect of wind on the net tension is more of a constant push than the short-term impact associated with a ball strike. For example, even strong wind gusts have a duration in seconds, while a serve regularly is double or triple that speed, and has an impact duration in milliseconds. Measuring the change of force relative to time (e.g., how fast the force changed from one millisecond to the next one or more) will isolate the signature of a ball impact, allowing it to be identified separately from any wind effect (which will be filtered out). This unique ball strike signature can be used to set the sensitivity for what will be triggered by the threshold force, indicating a "let" ball. With reference to Figure 9, which illustrates a chair umpire 90, and with continued reference to the embodiment of Figures 1-3B, the force F1 will be steeply lower during a ball strike (indicating contact as the ball presses the net downward, counteracting (lowering) the force F1 of the upward pull against the center-strap), while for the singles stick 43, the force F2 shown after a ball strike will be higher (as the ball slightly presses down on the net). If the change is short enough and strong enough, the threshold force will be reached (indicating a ball strike), thus triggering a beep or signal on the chair umpire device (i.e., the indicator). One example signal includes a vibration in a handset 92 used by the umpire 90. In this example, the armed button on the handset 92 pressed by the umpire 90 to activate the let detection function for the serve (i.e., during service) includes a haptic feedback device, such as an asymmetrical rotary device (e.g., an asymmetrical motor), configured to generate a vibration force when the threshold force is reached such that the umpire 90 feels the vibration when a let occurs, just as he might hear a beep. This ensures that the let is noticed by the umpire 90 even in a noisy stadium. Additionally or alternatively, the signal could include a light, such as an LED light turning, for example, from blue to red. The light and vibration may be used in combination with one another and/or in combination with the afore-mentioned beep, providing a redundant three senses signal (audio, haptic, visual) to ensure no let is missed by the umpire 90. The chair umpire 90 will activate the device only during a serve by pressing a button, which is then released, deactivating it as the point is under way (assuming there is no let or a service fault). At this time, a ball during a "rally" that clips the net, but lands into play on the other side, are not "lets" and are not replayed (these are typically called a "net cord" and play continues since the let rule only relates to serves). Signals indicating a net cord during a rally are neither needed nor desirable since it has no effect on play continuing. As shown in Figures 9 and 10, the handset 92 may be coupled via a wired or wireless connection to another computing device, such as a tablet 94, which is mounted adjacent the chair umpire 90. Both the handset 92 and the tablet 94 are considered "computing devices" for purposes of this disclosure. Together, the handset 92 and tablet 94 display information to the chair umpire 90 pertaining to an ongoing match and allow the chair umpire 90 to control various functionality of the systems used during an ongoing match. As examples, the handset 92 may be electrically coupled to the scale 30 and/or indicator 36 and may display different information, e.g., let detection, the net tension, in units of force (i.e., pounds), centerstrap height, ball mark inspection, shot clock, etc., on a screen of the handset 92 and/or the tablet 94. The handset 92 may also monitor the centerstrap height and display the same to the chair umpire 90. Further still, the handset 92 may display the strength of various electronic signals, such as electronic signals between the handset 92 and the tablet 94, and/or signals between the tablet 94 and the scale 30 and/or indicator 36. The tablet 94, typically referred to as a "scoring tablet," controls the scoring and other specific information during the match (as well as the set up prior to the match) but may complement or substitute for the display on the handset regarding the aforementioned functions of the net system. The handset 92 may include various buttons, including buttons for adjusting settings (e.g., algorithm, beep volume, etc.) and a SET button to enter settings (e.g., algorithm, beep volume, etc.). Further, the tablet 94 may include a software version of the handset 92, and thus the tablet 94 may be used in case of failure of the handset 92. To this end, this disclosure is not limited to use with systems including both a handset 92 and a tablet 94, and extends to systems having one, the other, or both. The handset 92 can be configured to display various information, such as displaying the volume of a beep during alet, for example, and including various LEDs and speakers to indicate, for example, pairing of a remote. The handset 92 and/or the tablet 94 may also show various warning signals, such as loss of wireless connection. In one example, when a wireless signal between the handset 92 and tablet 94 is lost, an LED flashing and "SIGNAL NONE" is displayed on the screen of the handset 92. The handset 92 and/or tablet 94 may also include a shot clock control button, which can send a signal to selectively start, pause, or resume the shot clock. The "shot clock" indicates on court the 25 second maximum time a player has to serve (i.e., start the next point) after the prior point has ended. As noted above, the handset 92 may also, upon pressing an "ARM" button, which may be an electronic button on a screen of the handset 92 for example, send a signal to the tablet 94 to arm a let detection function and to indicate play has started (i.e., a "Start of Point" signal), which may be sent over the internet around the world. Specifically, the "ARM" button may be pressed by the umpire 90 during service only, so that the let detection function is armed during service only, meaning lets, per the rules of tennis, are monitored during service only. The "ARM" button is typically deactivated during a rally such that the umpire (or players) is not distracted by notifications indicative of a non-service contact between the ball and net mid-rally. The handset 92 may also send a signal to the tablet 94, using the same button, indicating the next point has started, and which may be used by the tablet 94 to stop/disappear the shot clock from the on-court screen. The handset may manually send the signal to the tablet (using a key sequence) via a button on the handset to start, stop, pause, or resume the 25 seconds time allowed to commence the next point (much like a 30 second shot clock in basketball). The tablet may be connected to the shot clock (cable or wireless) and therefore can control its various function The handset may alternatively have a direct connection with the shot clock, wired or wireless, in order to control it. The handset 92 and/or table 94 may also receive signals from a ball mark inspection ("BMI") remote (not shown), which indicates that the chair umpire 90 has just left his or her chair to perform a ball mark inspection. This may occur during clay court tournaments when the umpire leaves his chair to see the mark a ball makes when it hits the court surface in order to check if the ball is in or out. The tablet 94 may, in turn, send a corresponding signal out to the world that all internet gambling is suspended until the score is input by the umpire 90 upon his or her return to the chair, which prevents chance opportunists on site from placing bets using real time information. This aspect of the disclosure has added relevance in the context of a clay court tournament where the ball makes a visible mark which allows the chair umpire to check a disputed line call. For hard court and grass, typically an automated system, such as the "Electronic Line Calling" is used to determine whether a ball lands inbounds and thus manual court inspection is never performed. The device can automatically reset without any manual intervention by the umpire and be ready for the next ball mark inspection. Other means of detecting when an umpire chair has left to make a ball mark inspection are publicly known, such as a pressure cushion or a so called "dead man's switch" which is a connection (one end to the chair and the other to the chair umpire) that is physically broken when two magnetically connected circuits are separated when the chair umpire leaves his chair. There are distinct disadvantages in such devices. In one aspect of this disclosure, a separate device, such as a secondary simplified handset, may be paired to a base which houses the scale 30 and configured to display the net tension, in units of force (i.e., Newtons). This separate device may be utilized by a grounds crew as they crank up the net, allowing them to see in real time the precise tension until they reach a target net tension. The target tension may be set at the beginning of the tournament and indicated on the display of the handset to show the preferred net tension. Typically, the handset 92 is only accessible by the chair umpire 90 and not accessible by the grounds crew. Rather than waiting for the umpire to arrive on court and give feedback, the grounds crew can have access to net tension information via the separate device. The separate device may pair to the scale 30, either by a wired or by contact, and preferably operating via wireless connection with the base (the net crank is on one of the two net posts 6.4m from the middle of the net where the base is). It may be particularly useful by the grounds crew when setting up the net during tournaments where the net will go up and down multiple times a day, thus ensuring the grounds crew can rapidly and safely reach the target net tension as they are operating a crank to apply tension to the net during set up. The separate device reduces, or eliminates, any need for the chair umpire to communicate the net tension to the grounds crew since the grounds crew has access to real time net tension via the separate device. The separate device may also show the battery level of the base, unit number, and other information. The let indication feature may also be useful in matches, such as club matches or recreational matches, which do not typically involve a chair umpire. Figure 7 schematically illustrates an embodiment in which an indicator is provided by a light 80. In this example, the light 80 has been incorporated into the scale 30.

In one example of use, the light 80 is normally not illuminated during play, and is configured to illuminate when the above-mentioned threshold force is reached. The light 80 may be an LED light configured to illuminate a color that is easily visible by the players, such as red. The red light may stay illuminated for a set period of time, such as 5 seconds, after the let occurs to allow the players to view the light. Thus, when the light is on immediately after a serve, the players know that a let has occurred. If the light, however, comes on during a rally (when play continues even if the ball clips the net cord), the players can ignore the light. Thus, positioning the light 80 on the scale 30, or alternatively in another location, near the bottom of the center-strap 22, for example, helps avoid distracting the players during play. In another example of use, the light 80 is always illuminated during play in a first color, such as green, which indicates that the above-mentioned threshold force has not been reached. When the threshold force is reached, the color of the light 80 changes to a second color, such as red. If the second color appears immediately following a serve, the players know that a let occurred. If the second color appears during a rally, the players can simply ignore the light. While only one side of the scale 30 is illustrated in Figure 7, it should be understood that there may be another light 80 on the opposite side of the scale 30 such that both players can see the light. Alternatively, the light 80 can be positioned on a side of the scale 30 such that it is visible from both sides of a tennis court. Further still, the light 80 could be positioned elsewhere, and need not be incorporated into the scale 30. For example, the light could be positioned below the center-strap 22 or could be positioned off the court in a location easily viewed by both players, such as a net post. Again, since there is no chair umpire or other individual to constantly turn the indicator on and off before a serve, the let detection system of the light 80 may always be activated during play, not just during service. Thus, this disclosure provides the light 80 in a location such that it does not distract the players during a rally, particularly where there is a let cord, but also such that players can easily view the light 80 when desired, such as during service and after a possible let. Figure 8 illustrates another example embodiment that is useful in situations where there is no chair umpire. In Figure 8, the indicator is provided by a speaker

82 configured to make a relatively loud beep when the above-mentioned threshold force is reached. In this example, the speaker 82 is incorporated into the scale 30, but, as with the light 80, that need not be the case. The speaker 82 could be positioned in another location adjacent the tennis court. Both players will be able to hear the beep from the speaker 82, indicating that a let has occurred. The embodiment of Figure 8 can be used in combination with the embodiment of Figure 7. That is, a beep could be used in combination with illumination of a light (or a change in color of an already-illuminated light) to indicate that a let has occurred. It will be appreciated that players could have the ability to activate the let detection function right before a serve, and where the device would automatically de-activate seconds later in order to avoid a possible let signal in a rally. Either or both of the players could activate the device, say, by pressing a button on their person or racket wirelessly connected to the base that activates it right before the serve. While this would require one of the players to remember to activate the device each time before a serve is made, it provides the option of activation of the device only at the time of the serve. That said, the embodiments of Figures 7 and 8 are provided such that the signal, whether audio, visual, or otherwise, will not disturb players during a rally, but the signal could be such that if one player believes that a let occurred, that both players can use the disclosed device to confirm that a let did indeed occur. For example, an example visual signal could be a bright, flashing light, or alternatively could be a discrete light or beep that avoids distracting players but will still provide confirmation if a player calls a let. Thus, since most tennis is not played at the professional level, where chair umpires are always used, this disclosure provides amateur players with a way to enforce an important rule in tennis - the let rule. Although the different examples have the specific components shown in the illustrations, embodiments of this claimed invention are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples. Furthermore, it is appreciated that distances or features in the drawings may be reduced or exaggerated for illustrative purposes and do not in any way so limit the embodiment shown.

Additional aspects of this disclosure relate to active control of the shot clock without requiring a chair umpire or other individual to press a button, such as a physical or digital button on a handset 92 or the tablet 94. A first exemplary embodiment relates to active control of the shot clock using sound and/or speech associated with the chair umpire. Another exemplary embodiment relates to the use of hand or facial gestures to control the shot clock. As mentioned, the shot clock may be actively controlled using speech recognition and voice/sound activation. This aspect of the disclosure may be referred to as speech recognition functionality or voice activation functionality. In this aspect, the tablet 94, handset 92, or both, are in communication with or include a voice-user interface, such as a microphone, and a voice command device, which is a device controlled with a voice-user interface. The voice-user interface and voice command device may be combined into a smart device including a microphone, a hardware platform able to perform language processing, and software. Alternatively, the voice-user interface could include a microphone and the voice command device could be provided by the hardware and software associated with the tablet 94, for example. In that instance, the microphone could be incorporated into the handset 92. In another example, the microphone could be provided by a microphone 96 (Figure 9) that is typically adjacent the umpire chair for use by the chair umpire 90 in announcing the score of a match and/or making other announcements. In addition to being coupled to various speakers and/or other electronic equipment, the microphone 96 may be coupled to the voice command device, such as the tablet 94. In an example, the shot clock is controlled by the speech of the chair umpire 90 as the chair umpire 90 speaks into the microphone 96. Specifically, the voice user interface which again may be the microphone 96, picks up the speech of the chair umpire 90 and the voice command device, which again may be the tablet 94, interprets the speech of the chair umpire 90 as commands to control the shot clock. In a particular example, after inputting the score after a point, the chair umpire 90 may announce the score via the microphone 96 located adjacent to the umpire chair. When the tablet 94 identifies certain speech from the chair umpire 90 as an announced score, the tablet 94 will automatically start the shot clock without requiring the chair umpire 90 to press a physical or digital button on the tablet 94 or handset 92. Once the point has started, the speech recognition functionality may automatically be turned off, such as when the "ARM" button is pressed, until the point ends and the score is then inputted into the scoring tablet. Just moments later, the chair umpire 90 will announce the score for spectators (both live and on television) and the players. The chair umpire 90 may choose to wait to announce the score in order to allow the crowd to settle down after a long and exciting point. This aspect of the disclosure naturally allows the chair umpire 90 to delay the start of the shot clock when the players have just finished a demanding point with along rally, particularly if at an event played in hot weather. Using this aspect of the disclosure, the shot clock will not be strictly controlled by starting instantly following completion of every point, nor by manually pressing a button or touch screen, but instead will naturally follow the pace of the particular stage in the tennis match. Also by the shot clock starting upon the announcing of the score, the players are made aware that the 25 second time limit until the next point has then commenced. In this example, the start of the shot clock will be triggered by the chair umpire's announcement of the score, rather than an inputting of the score into the scoring tablet when the point concludes, which is typically when the ball is called out or fails to travel over the net. By having a proper sequence and timing, a chair umpire calling a "let" directly after the start of point has been pressed, or calling "fault" or "out" or "correction" would not start the shot clock since the score had not yet been inputted into the scoring tablet, nor has there been a pre-set delay required after the score is inputted before any key words, voice or sound could control the shot clock. The control of the shot clock could be limited to only reacting to sound or speech spoken specifically into the chair umpire microphone 96, thus avoiding other sounds such as from cheering spectators. For announcements of an Electronic Line calling Challenge Review, e.g., Hawkeye or Foxtenn, where the score may be inadvertently inputted before the challenge from the player is made known, the chair umpire 90 will first input the challenge into the scoring tablet before orally announcing the challenge and then the result. When the challenge is made, the voice activation functionality will be deactivated until the result of the challenge and/or score is imputed into the scoring tablet. It should be understood that the software for the speech recognition functionality may automatically recognize particular key words, such as those associated with a score, which assures that other use of the microphone would not inadvertently start the shot clock. Alternatively, for a simpler system, any audible sound picked up by the microphone 96 during an allowed time frame, namely some period of time after the score is inputted, would trigger the start of the shot clock without any need to recognize any particular words. The audible sound may be of a particular decibel, that may be similar to that which the chair umpire uses to announce a score. The period of time may be up tol0 seconds, as an example. Such as system is still considered speech recognition and voice activation in this disclosure as the sounds of the voice of the chair umpire 90 trigger control of the shot clock. In this simpler system, the system may monitor for sounds within an appropriate decibel range of a typical announcement of the score. An advantage of this system is that it does not require speech recognition and is not limited by language. Further, the shot clock could be controlled using one of the aforementioned buttons, either on the tablet 94 or the handset 92, in conjunction with the aforementioned speech recognition functionality. As an example, following a point, the shot clock could be configured to start following the first-occurring of (1) the chair umpire 90 pressing an appropriate button on the handset 92 or (2) the announcement of the score through the microphone 96. Further, if due to noise of some other reason, the speech recognition functionality malfunctions in part or in whole, the tablet 94 and/or the handset 92 may be used for shot clock control, in the manner discussed above. As an example, if the speech recognition system inadvertently starts the shot clock too early, the tablet 94 and/or handset 92 may be used to pause and restart the shot clock at the appropriate time. Further, as mentioned, the shot clock may be actively controlled using one or more gestures, such as hand gestures or facial gestures, of the chair umpire 90. A camera 100 (Figure 9) may be mounted adjacent the chair umpire 90 and may be configured to acquire images, such as still pictures and video, of the chair umpire 90. The camera 100 may be standalone camera or may be incorporated into another device, such as the tablet 94. The images from the camera 100 may be sent to another computer, such as the tablet 94, and processed to identify one or more known facial or hand gestures. When a known gesture is identified, the shot clock is actively controlled. In an example, the chair umpire 90 may present the palm of their hand toward the camera 100. When the tablet 94, for example, identifies the palm of a hand in the images from the camera 100, the tablet 94 will generate a signal to start the shot clock. If, after the shot clock has begun and before it is deactivated by the "ARM" button, the chair umpire 90 can stop the shot clock by presenting the same gesture to the camera 100 again or using another gesture. While presenting a palm is mentioned, other hand or facial gestures may be used to start the shot clock, stop the shot clock, and/or reset the shot clock. Instead of a camera 100, a proximity sensor could be used. The proximity sensor would generate a signal to start the shot clock, for example, when a chair umpire 90 has placed a body part, such as a palm of the hand, in close proximity to the proximity sensor. The proximity sensor may be located on the handset, a further handset, or the tablet. An additional or alternate sensor for triggering the shot clock may be located on the handset or a further handset. The additional sensor may be a sensor screen on the handset or additional handset on any part thereof. This may trigger the shot clock by either a motion over it or by physically touching the screen. Such a "virtual" button can substitute for the physical button typically on the handset

Although the different examples have the specific components shown in the illustrations, embodiments of this claimed invention are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples. For example, while the forces F1 and F2 are substantially perpendicular to the length L of the net 12, in an alternate embodiment the scale 30 is arranged to measure the tension in the upper cable 18 directly, although this arrangement may lack sensitivity and responsiveness for the required measurements. As another example, while specific distances such as 107 cm and 91.4 cm have been mentioned above, as currently required by all tennis governing bodies, it should be understood that this disclosure extends to systems including other distances which may include other sports which employs nets. For instance, if the regulations from the tennis governing bodies are followed, the difference between the height at the net posts 16 and the center-strap 22 will be 15.6 cm. However, in some instances the regulations are not followed, resulting in a height difference of about 15.6 cm. As used herein, the term "about" is not a boundaryless term, and should be interpreted in the way one skilled in the art would interpret the term. Similarly, measurements as described in the screen readout are given as examples only and will be different under use. Suitably, the handset and/or further handset is wirelessly connected to the tablet. This enables the handset, or further handset, to be taken away from the umpire chair, for example whilst checking the net tension, during the pre-play coin toss/warm-up, and/or during a BMI check. The wireless connection can be of any suitable type, although it is envisaged that point-to-point RF communications may be used or Bluetooth@ or WiFi. A dedicated, non-public RF communications link is the preferred option as it reduces the likelihood of third parties being able to "listen in" on the data and/or being able to interfere with it. Finally, referring now to Figures 11 and 12 of the drawings, a typical force, as measured by the scale, plotted as a function of time is shown in the drawings. It should be noted that the axes of Figures 11 and 12 are not drawn to scale, but are exaggerated to better represent the invention. In Figure 11, measured net tension, i.e. the force F, on the scale is measured as a function of time t. There is a baseline net tension value 100, which is the nominal net tension of the net. On an outdoor court, for example, fluctuations in wind speed may cause high-periodicity fluctuations in the measured force F as a function of time. It can be seen, therefore, the net tension, or measured force F, varies up 102 or down 104 in a generally sinusoidal or wave-like manner oscillating generally about the nominal net tension value 100. However, when a ball strikes the net, for example, during a let serve, there is a "fingerprint" comprised of dip and/or peak in the measured force F and the

"fingerprint" is shown schematically in Figure 11 by the sharp oscillation 106. Referring to Figures 12A to 12E of the drawings, the "fingerprint" 106 can take various forms. Specifically, in Figure 12A, the fingerprint 106 is a sharp dip in the measured force F. In Figure 12B, the fingerprint 106 is a sharp peak in the measured net force F. In Figure 12C, the fingerprint 106 is a sharp peak followed by a dip in the measured force F. In Figure 12D, the fingerprint 106 is a sharp dip followed by a peak in the measured force F. In Figure 12E, the fingerprint 106 is a series of peaks and dips, generally following a "damped oscillation"profile. It will be appreciated that the time axis in Figures 12A to 12E has been greatly expanded compared to that in Figure 11, purely for illustration purposes. It will also be appreciated that pursuant to a standard rebound effect (Newton's Third Law), the net tension may continue to oscillate after each ball impact in a continued ever reducing amplitude until the net tension may reach its base line stable level. The following statements are not the claims, but relate to various possible features or embodiments of the disclosure: Statement 1. A method, comprising: measuring a force exerted by a net on a connector, the net connected to a playing area by way of the connector, the connector provided between a pair of net posts supporting the net on opposite sides of the playing area; indicating, using an indicator, whether a threshold force has been met or exceeded during a short duration using at least one of (1) a vibration force, (2) a light, and (3) a sound, the threshold force being indicative of an impact between a ball and the net; and arming a let detection function by pressing a button on one of a handset and a tablet, and wherein the indicating step is only performed when the let detection function has been armed. Statement 2. The method as recited in statement 1, wherein the arming step includes pressing a button on a screen of one of the handset and the tablet. Statement 3. The method as recited in statement 1, wherein the arming step is performed during service in a tennis match. Statement 4. The method as recited in statement 3, wherein the arming step is not performed during a rally of the tennis match such that the indicating step is not performed during the rally. Statement 5. The method as recited in statement 1, wherein the indicator includes a haptic feedback device, and wherein the indicating step includes generating the vibration force with the haptic feedback device. Statement 6. The method as recited in statement 1, wherein the indicator includes alight, and wherein the indicating step includes illuminating the light after the threshold force has been met or exceeded. Statement 7. The method as recited in statement 6, wherein indicating step includes illuminating the light in a first color when the threshold force has not been met or exceeded and illuminating the light in a second color different than the first color when the threshold force has been met. Statement 8. The method as recited in statement 1, wherein the indicator is an audio indicator, and wherein the indicating step includes generating the sound when the threshold force has been met. Statement 9. The method as recited in statement 1, wherein the threshold force is based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a scale during the short duration. Statement 10. The method as recited in statement 1, wherein a button is pressed on the handset which sends a signal to the tablet to start, stop, pause, or resume a shot clock in order to help enforce the time limit a player may take during his service game. Statement 11. A net tension system, comprising: a net spanning a playing area, wherein the net is supported by a pair of net posts on opposite sides of the playing area; a connector between the net posts, the net connected to the playing area by way of the connector; a scale measuring a force exerted by the net on the connector; an indicator expressing when a threshold force measured by the scale has been met or exceeded during a short duration using at least one of (1) a vibration force, (2) a light, and (3) a sound, the threshold force being indicative of an impact between a ball and the net; a computing device including a button which, when activated, arms a let detection function, and wherein the indicator is only operable when the button is activated. Statement 12. The net tension system as recited in statement 11, wherein the computing device is one of a handset and a tablet. Statement 13. The net tension system as recited in statement 12, wherein the computing device is mounted upon or adjacent to a chair of a chair umpire. Statement 14. The net tension system as recited in statement 11, wherein the indicator includes a haptic feedback device, and wherein the vibration force is generated by the haptic feedback device when the threshold force is met when a ball comes into contact with the net during a serve. Statement 15. The net tension system as recited in statement 14, wherein the haptic feedback device is incorporated into a handset used by an umpire, official, or other person. Statement 16. The net tension system as recited in statement 11, wherein the indicator includes a light, and wherein the indicator illuminates the light when the threshold force has been met. Statement 17. The net tension system as recited in statement 11, wherein the indicator is an audio indicator configured to generate the sound when the threshold force has been met. Statement 18. The net tension system as recited in statement 12 wherein the handset includes a button to control a shot clock that is used to enforce the time limit between points. Statement 19. The net tension system as recited in statement 11, wherein the threshold force is based on a fingerprint and the fingerprint is a unique sharp spike in an output of the scale during the short duration. Statement 20. The net tension system as recited in statement 12, further comprising: a remote device that can detect when a chair umpire leaves his chair for a ball mark inspection; said remote device is placed on the person of the chair umpire, for example, in his pocket; said remote device is wirelessly connected to the handset or tablet connected to the handset; said remote device will send a signal to the handset when said remote device has detected the chair umpire has left his chair and descended down to a court; said handset will in turn send a signal to the tablet; and said tablet connected to the internet will send a message to particular parties that the chair umpire has left his chair to make a ball mark inspection in order that said parties may take particular action, such as suspend betting related to a match. Statement 21. The net tension system as recited in statement 20, wherein the remote device may pair and connect to the handset or tablet via a close proximity between thetwo. Statement 22. The method as recited in statement 1, further comprising: a remote device that can detect when a chair umpire leaves his chair for a ball mark inspection; said remote device is placed on the person of the chair umpire, for example, in his pocket said remote device is wirelessly connected to the handset or tablet connected to the handset; said remote device will send a signal to the handset when said remote device has detected the remote chair umpire has left his chair and descended down to a court; said handset will in turn send a signal to the tablet; said tablet connected to the internet will send a message to particular parties that the chair umpire has left his chair to make a ball mark inspection in order that said parties may take particular action, such as suspend betting related to a match. Statement 23. The method as recited in statement 22, wherein a remote device may pair and connect to the handset or tablet via a close proximity between the two. Statement 24. A method, comprising: measuring a force associated with a net extending across a tennis court; indicating, using an indicator, whether the force meets or exceeds a threshold force during a short duration using at least one of (1) a vibration force, (2) a light, and (3) a sound, the threshold force being indicative of an impact between a ball and the net; pressing a button on a handset to arm alet detection function, wherein the indicating step is only performed when the let detection function has been armed; and pressing a button on one of the handset and the tablet to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match. The method may further include activating a second handset which is directed to start a pre-match shot clock which times the 1 minute time period that players have to come to a coin toss and also a subsequent 5 minute warm up. Alternatively, this second handset may also be used to control the shot clock even during the match. The handset may be a remote handset, and may be connected wirelessly or by cable, to a structure in a position that can be accessed by a chair umpire. Statement 25. The method as recited in statement 24, wherein the step of pressing the button controls the shot clock to help enforce a time limit imposed upon the player during a service game. Statement 26. The method as recited in statement 24, wherein the shot clock is situated on the tennis court.

Statement 27. The method as recited in statement 24, wherein controlling the shot clock includes starting, stopping, pausing, resuming, or resetting the shot clock. Statement 28. The method as recited in statement 27, wherein a button is pressed on the handset which sends a signal to the tablet to start, stop, pause, resume or re-set the shot clock. Statement 29. The method as recited in statement 24, wherein the let detection function is armed during the service game of the player and is not armed during a rally of the tennis match such that the indicating step is not performed during the rally. Statement 30. The method as recited in statement 24, wherein the indicator, e.g. handset, includes a haptic feedback device, and the indicating step includes generating the vibration force with the haptic feedback device when the threshold force has been met or exceeded. Statement 31. The method as recited in statement 30, wherein the haptic feedback device is incorporated into the handset. Statement 32. The method as recited in statement 24, wherein the indicator, e.g. handset, includes alight, and the indicating step includes illuminating the light. Statement 33. The method as recited in statement 32, wherein the indicating step includes illuminating the light in a first color when the threshold force has not been met or exceeded and further includes illuminating the light in a second color different than the first color when the threshold force has been met or exceeded. Statement 34. The method as recited in statement 24, wherein the indicator is an audio indicator, and the indicating step includes generating the sound when the threshold force has been met or exceeded. Statement 35. The method as recited in statement 24, wherein the threshold force is based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve. Statement 36. A system, comprising: a net extending across a tennis court; an indicator expressing when a force associated with the net exceeds a threshold force during a short duration using at least one of (1) a vibration force, (2) a light, and (3) a sound, the threshold force being indicative of an impact between a ball and the net; and a computing system, which includes a force measuring sensor/device or base attached to the net which calculates if there has been a ball impact, a handset including a button which, when pressed, arms a let detection function, wherein the indicator is only operable when the let detection function is armed, and the computing system further includes a button which, when pressed, controls a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match. The handset receives the data packet from the force measuring sensor/device indicating alet call, for alerting the umpire. The force measuring sensor/device is in wireless connection with the handset and can provide ongoing information to the handset. Statement 37. A system, comprising: a net extending across a tennis court; an indicator expressing when a force associated with the net exceeds a threshold force during a short duration using at least one of (1) a vibration force, (2) a light, and (3) a sound, the threshold force being indicative of an impact between a ball and the net; and a computing system, which includes a base attached to the net which calculates if there has been a ball impact, a handset including a button which, when pressed, arms alet detection function, wherein the indicator is only operable when the let detection function is armed, and the computing system further includes a button which, when pressed, controls a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match. The handset receives the data packet from the force base indicating alet call, for alerting the umpire. The base is in wireless connection with the handset and can provide ongoing information to the handset. Statement 38. The system as recited in statement 36 or 37, wherein the computing system includes at least one of a handset and a tablet. Statement 39. The system as recited in statement 38, wherein the handset includes the button which, when pressed, sends a signal to the tablet. Alternatively the handset can be connected directly to the shot clocks located on the court or a router that is connected to the shot clock/s. There is at least one shot clock located on or near each end of a court (on or adjacent to the backstop), and sometimes up to two shot clocks on each end (total of four) so that players have a clear view of the time left before needing to serve. The system is applied to all the shot clocks that are being used on a Court, i.e. typically one or two at each end of the court. Statement 40. The system as recited in statement 36 or 37, wherein the shot clock is situated on the tennis court. Statement 41. The system as recited in statement 36 or 37, wherein the computing system is at least partially mounted upon or adjacent to a chair of a chair umpire. Statement 42. The system as recited in statement 36 or 37, wherein the indicator includes a haptic feedback device incorporated into a handset used by an umpire, official, or other person, and the vibration force is generated by the haptic feedback device when the threshold force is met or exceeded. Statement 43. The system as recited in statement 36 or 37, wherein the indicator includes one of a light and an audio indicator. Statement 44. The system as recited in statement 36 or 37, wherein the threshold force is based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve. Statement 45. A method, comprising: measuring a force associated with a net extending across a tennis court; indicating, using an indicator, whether the force meets or exceeds a threshold force during a short duration using at least one of (1) a vibration force, (2) a light, and (3) a sound, the threshold force being indicative of an impact between a ball and the net; pressing a button on one of a handset and a tablet to arm a let detection function, wherein the indicating step is only performed when the let detection function has been armed; and pressing a button, e.g. a further button, on one of: the handset; a further handset; and the tablet to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match. The steps described in the claims are not necessarily carried out in the sequential order in which they are listed in the claims. Statement 46: The system as recited in statement 45, wherein the pressing a button to control a shot clock occurs before the pressing a button to arm a let detection function. In practice, the shot clock comes first because it is timing the 25 seconds until the player serves, e.g. when the umpire arms the let detection system. The system may include a separate button not integrated in the main handset that is used to control the shot clock. For example the second handset may include a separate button to control the pre-match shot clock. In one form, the system may include a button, e.g. a fixed handset button, attached to the umpire chair structure which the umpire may use for the pre-match shot clock. On the more important shot clock control used during the match, there could be a shot clock button on a distinct handset up on or adjacent to a shelf on the umpire chair structure where the scoring tablet is positioned, alongside the usual let detection handset. One of ordinary skill in this art would understand that the above-described embodiments are exemplary and non-limiting and do not narrow down or limit the scope of the claims. That is, modifications of this disclosure would come within the scope of the claims. Accordingly, the following claims should be studied to determine their true scope and content.

Claims

CLAIMS 1. A method, comprising: measuring a force associated with a net extending across a tennis court; indicating, using an indicator, whether the force meets or exceeds a threshold force during a short duration using at least one of (1) a vibration force, (2) a light, and (3) a sound, the threshold force being indicative of an impact between a ball and the net; pressing a button on one of a handset and a tablet to arm a let detection function, wherein the indicating step is only performed when the let detection function has been armed; and pressing a button on one of: the handset; a further handset; and the tablet to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match.
2. A method, comprising: measuring a force associated with a net extending across a tennis court; indicating, using an indicator, whether the force meets or exceeds a threshold force during a short duration using at least one of (1) a vibration force, (2) a light, and (3) a sound, the threshold force being indicative of an impact between a ball and the net; pressing a button on one of a handset and a tablet to arm a let detection function, wherein the indicating step is only performed when the let detection function has been armed; and pressing a button included in the same one of: the handset; and the tablet to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match.
3. The method of claim 1 or claim 2, wherein the step of pressing the button controls the shot clock to help enforce a time limit imposed upon the player during a service game.
4. The method of any one of claims 1 to 3, wherein the shot clock is situated on the tennis court.
5. The method of any one of claim 1 to 4, wherein controlling the shot clock includes starting, stopping, pausing, or resuming the shot clock.
6. The method of claim 5, wherein a button is pressed on the handset which sends a signal to the tablet to start, stop, pause, or resume the shot clock.
7. The method of any one of claim 1 to 4, wherein controlling the shot clock includes starting, stopping, pausing and resuming the shot clock.
8. The method of claim 7, wherein a button is pressed on the handset which sends a signal to the tablet to start, stop, pause and resume the shot clock.
9. The method of any one of claims 1 to 8, wherein the let detection function is armed during the service game of the player and is not armed during a rally of the tennis match such that the indicating step is not performed during the rally.
10. The method of one of claims 1 to 9, wherein the indicator includes a haptic feedback device, and the indicating step includes generating the vibration force with the haptic feedback device.
11. The method of claim 10, wherein the haptic feedback device is incorporated into the handset.
12. The method of any one of claims 1 to 9, wherein the indicator includes a light, and the indicating step includes illuminating the light.
13. The method of claim 12, wherein the indicating step includes illuminating the light in a first color when the threshold force has not been met or exceeded and further includes illuminating the light in a second color different than the first color when the threshold force has been met or exceeded.
14. The method of any one of claims 1 to 9, wherein the indicator is an audio indicator, and the indicating step includes generating the sound when the threshold force has been met or exceeded.
15. The method of any one of claims 1 to 14, wherein the threshold force is based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve.
16. The method of any one of claims 1 to 15, further comprising: using a remote device or the further handset to detect when a chair umpire leaves his chair for a ball mark inspection; said remote device or further handset being placed on the person of the chair umpire, said remote device being wirelessly connected to the handset or tablet connected to the handset; said remote device being configured to send a signal to the handset when said remote device has detected the remote chair umpire has left his chair and descended down to a court; said handset sending a signal to the tablet; said tablet being connected to the internet and being configured to send a message to specified parties that the chair umpire has left his chair to make a ball mark inspection in order that said parties may take particular action, such as to suspend betting related to a match.
17. The method of any one of claims 1 to 16, wherein pressing the arming button additionally indicates the next point has started.
18. The method of claim 17, further comprising connecting pairing and connecting the remote device or further handset to the handset or tablet when the two are in close proximity.
19. A system, comprising: a net extending across a tennis court; an indicator expressing when a force associated with the net exceeds a threshold force during a short duration using at least one of (1) a vibration force, (2) a light, and (3) a sound, the threshold force being indicative of an impact between a ball and the net; and a computing system including a button which, when pressed, arms a let detection function, wherein the indicator is only operable when the let detection function is armed, and the computing system further includes a button which, when pressed, controls a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match.
20. The system of claim 19, wherein the computing system includes at least one of a handset, a further handset, and a tablet which includes the button.
21. The system of claim 19 or claim 20, wherein the shot clock is situated on the tennis court.
22. The system of any one of claims 19 to 21, wherein the computing system is at least partially mounted upon or adjacent to a chair of a chair umpire.
23. The system of any one of claims 19 to 22, wherein the indicator includes a haptic feedback device incorporated into the handset or further handset used by an umpire, official, or other person, and the vibration force is generated by the haptic feedback device when the threshold force is met or exceeded.
24. The system of any one of claims 19 to 22, wherein the indicator includes one of a light and an audio indicator.
25. The system of any one of claims 19 to 24, wherein the threshold force is based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve.
26. The system of any one of claims 19 to 25, further comprising: a remote device or further handset that can detect when a chair umpire leaves his chair for a ball mark inspection; said remote device or further handset being placed on the person of the chair umpire; said remote device or further handset being wirelessly connected to the handset or tablet connected to the handset; said remote device of further handset being configured to send a signal to the handset when said remote device or further handset has detected the chair umpire has left his chair and descended down to a court; said handset being configured to send a signal to the tablet; and said tablet being connected to the internet and being configured to send a message to specified parties that the chair umpire has left his chair to make a ball mark inspection in order that said parties may take particular action, such as suspend betting related to a match.
27. The system of claim 26, wherein the remote device or further handset pair to and connects to the handset or tablet when it is in close proximity thereto.
28. A method, comprising: using an indicator to indicate by one of a vibration force, a light or a sound, indicating that movement of a tennis net caused by the force of an impact between a ball and the net has occurred during a serve; pressing a button on one of a handset; a further handset; and a tablet to arm a let detection function, wherein the indicating step is only performed when the let detection function has been armed; and pressing a button on a different one of: the handset; the further handset; and the tablet to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match.
29. A method, comprising: using an indicator to indicate by one of a vibration force, a light or a sound, indicating that movement of a tennis net caused by the force of an impact between a ball and the net has occurred during a serve; pressing a button on one of a handset; a further handset; and a tablet to arm a let detection function, wherein the indicating step is only performed when the let detection function has been armed; and pressing a button on the same one of: the handset; the further handset; and the tablet to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match.
30. The method of claim 28 or claim 29, wherein the step of pressing the button controls the shot clock to help enforce a time limit imposed upon the player during a service game.
31. The method of any one of claim 28 to 30, wherein the shot clock is situated on the tennis court.
32. The method of any one of any one of claims 28 to 31, wherein controlling the shot clock includes starting, stopping, pausing, or resuming the shot clock.
33. The method of claim 32, wherein a button is pressed on the handset which sends a signal to the tablet to start, stop, pause, or resume the shot clock.
34. The method of any one of claims 28 to 31, wherein controlling the shot clock includes starting, stopping, pausing and resuming the shot clock.
35. The method of claim 34, wherein a button is pressed on the handset which sends a signal to the tablet to start, stop, pause and resume the shot clock.
36. The method of any one of any one of claims 28 to 35, wherein the let detection function is armed during the service game of the player and is not armed during a rally of the tennis match such that the indicating step is not performed during the rally.
37. The method of any one of any one of claims 28 to 36, wherein the indicator includes a haptic feedback device, and the indicating step includes generating the vibration force with the haptic feedback device.
38. The method of claim 37, wherein the haptic feedback device is incorporated into the handset.
39. The method of any one of any one of claims 28 to 36, wherein the indicator includes a light, and the indicating step includes illuminating the light.
40. The method of any one of any one of claims 28 to 36, wherein the indicator is an audio indicator, and the indicating step includes generating the sound.
41. The method of any one of any one of claims 26 to 40, further comprising measuring a force associated with a net extending across a tennis court, and wherein the indicating step occurs when the force meets or exceeds a threshold force during a short duration.
42. The method of claim 41, wherein the threshold force is based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve.
43. The method of any one of any one of claims 28 to 42, wherein the step of pressing the button to arm the let detection function including pressing a button on the handset, the step of pressing the button to control the shot clock includes pressing a button on the handset, and the handset includes the indicator.
44. A method, comprising: using a detector to detect if there has been movement of a tennis net caused by the force of an impact between a ball and the net has occurred during a serve; pressing a button on one of a handset; a further handset; and a tablet to arm a let detection function, wherein the detection of movement is only performed when the let detection function has been armed; and pressing a button on the same one of: the handset; the further handset; and the tablet to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match.
45. The method of claim 44, wherein the step of pressing the button controls the shot clock to help enforce a time limit imposed upon the player during a service game.
46. The method of claim 44 or claim 45, wherein the shot clock is situated on the tennis court.
47. The method of any one of any one of claims 44 to 46, wherein controlling the shot clock includes starting, stopping, pausing, or resuming the shot clock.
48. The method of claim 47, wherein a button is pressed on the handset which sends a signal to the tablet to start, stop, pause, or resume the shot clock.
49. The method of any one of claims 44 to 46, wherein controlling the shot clock includes starting, stopping, pausing and resuming the shot clock.
50. The method of claim 49, wherein a button is pressed on the handset which sends a signal to the tablet to start, stop, pause and resume the shot clock.
51. The method of any one of any one of claims 44 to 50, wherein the let detection function is armed during the service game of the player and is not armed during a rally of the tennis match such that the indicating step is not performed during the rally.
52. The method of any one of any one of claims 44 to 51, wherein an indicator is used to indicate when movement has been detected.
53. The method of claim 53, wherein the indicator includes a haptic feedback device, and the indicating step includes generating the vibration force with the haptic feedback device.
54. The method of claim 53, wherein the haptic feedback device is incorporated into the handset.
55. The method of any one of claim 52, wherein the indicator includes a light, that illuminates when movement has been detected.
56. The method of claim 52, wherein the indicator is an audio indicator, that generates sound when movement has been detected.
57. The method of any one of any one of claims 44 to 56, wherein movement is detected by measuring a force associated with a net extending across a tennis court, and wherein the indicating step occurs when the force meets or exceeds a threshold force during a short duration.
58. The method of claim 57, wherein the threshold force is based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve.
59. The method of any one of any one of claims 44 to 58, wherein the step of pressing the button to arm the let detection function including pressing a button on the handset, the step of pressing the button to control the shot clock includes pressing a button on the handset, and the handset includes the indicator.
60. A method, comprising: indicating, using an indicator, that an impact between a ball and a tennis net has occurred; pressing a button on one of a handset and a tablet to arm a let detection function, wherein the indicating step is only performed when the let detection function has been armed; and pressing a button on one of the handset and the tablet to control a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match.
61. The method of claim 60, wherein the step of pressing the button controls the shot clock to help enforce a time limit imposed upon the player during a service game.
62. The method of claim 60 or claim 61, wherein the shot clock is situated on a tennis court.
63. The method of any one of claims 60 to 62, wherein controlling the shot clock includes starting, stopping, pausing, or resuming the shot clock.
64. The method of claim 63, wherein a button is pressed on the handset which sends a signal to the tablet to start, stop, pause, or resume the shot clock.
65. The method of any one of claims 60 to 62, wherein controlling the shot clock includes starting, stopping, pausing and resuming the shot clock.
66. The method of claim 65, wherein a button is pressed on the handset which sends a signal to the tablet to start, stop, pause and resume the shot clock.
67. The method of any one of claims 60 to 66, wherein the let detection function is armed during the service game of the player and is not armed during a rally of the tennis match such that the indicating step is not performed during the rally.
68. The method of any one of claims 61 to 67, wherein the indicator includes a haptic feedback device, and the indicating step includes generating a vibration force with the haptic feedback device.
69. The method of claim 68, wherein the haptic feedback device is incorporated into the handset.
70. The method of any one of claims 61 to 67, wherein the indicator includes a light, and the indicating step includes illuminating the light.
71. The method of any one of claims 61 to 67, wherein the indicator is an audio indicator, and the indicating step includes generating a sound.
72. The method of any one of claims 61 to 71 further comprising: measuring a force associated with a net extending across a tennis court, and wherein the indicating step occurs when the force meets or exceeds a threshold force during a short duration.
73. The method of claim 72, wherein the threshold force is based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve.
74. The method of any one of claims 61 to 73, wherein the indicating step occurs following a perturbation of the tennis net.
75. The method of any one of claims 61 to 74, wherein the step of pressing the button to arm the let detection function including pressing a button on the handset, the step of pressing the button to control the shot clock includes pressing a button on the handset, and the handset includes the indicator.
76. A system, comprising: an indicator configured to express that an impact between a ball and a tennis net has occurred; and a computing system including a button which, when pressed, arms a let detection function, wherein the indicator is only operable when the let detection function is armed, and the computing system further includes a button which, when pressed, controls a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match.
77. The system of claim 76, wherein the computing system includes at least one of a handset and a tablet.
78. The system of claim 77, wherein the handset includes the button which, when pressed, sends a signal to the tablet to start, stop, pause, or resume the shot clock.
79. The system of claim 78, wherein the button configured to arm the let detection function and the button configured to control the shot clock are on the handset.
80. The system of cany one of claims 76 to 79, wherein the handset includes the indicator.
81. The system of any one of claims 76 to 80, wherein the shot clock is situated on a tennis court.
82. The system of any one of claims 76 to 81, wherein the computing system is at least partially mounted upon or adjacent to a chair of a chair umpire.
83. The system of any one of claims 76 to 82, wherein the indicator includes a haptic feedback device, a light, or an audio indicator.
84. The system of any one of claims 76 to 82, wherein the indicator is configured to express that the impact has occurred when a force associated with the net exceeds a threshold force during a short duration.
85. The system of claim 84, wherein the threshold force is based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve.
86. The system of any one of claims 76 to 85, wherein the indicator is configured to express that the impact has occurred following a perturbation of the tennis net.
87. A system, comprising: a detector to detect if there has been movement of a tennis net due to the force of an impact of a tennis ball during a serve; a computing system including a button which, when pressed, arms a let detection function, wherein the detector is only operable when the let detection function is armed, and the computing system further includes a button which, when pressed, controls a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match.
88. The system of claim 87, wherein the computing system includes at least one of a handset and a tablet.
89. The system of claim 88, wherein the handset includes the button which, when pressed, sends a signal to the tablet to start, stop, pause, or resume the shot clock.
90. The system of claim 89, wherein the button configured to arm the let detection function and the button configured to control the shot clock are on the handset.
91. The system of any one of claims 87 to 90, wherein the handset includes the indicator.
92. The system of any one of claims 87 to 91, wherein the shot clock is situated on a tennis court.
93. The system of any one of claims 87 to 92, wherein the computing system is at least partially mounted upon or adjacent to a chair of a chair umpire.
94. The system of any one of claims 87 to 93, comprising and indicator to indicate when movement of the net has been detected.
95. The system of claim 94, wherein the indicator includes a haptic feedback device, a light, or an audio indicator.
96. The system of claim 94 or claims 95, wherein the indicator is configured to express that the impact has occurred when a force associated with the net exceeds a threshold force during a short duration.
97. The system of claim 98, wherein the threshold force is based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve.
98. The system of any one of claims 94 to 97, wherein the indicator is configured to express that the impact has occurred following a perturbation of the tennis net.
99. A method, comprising: indicating, using an indicator, that an impact between a ball and a tennis net has occurred; pressing a button on one of a handset and a tablet to arm a let detection function, wherein the indicating step is only performed when the let detection function has been armed; and actively controlling a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match without pressing a physical or digital button on the handset or the tablet.
100. The method of claim 99, wherein the step of actively controlling the shot clock includes using speech recognition.
101. The method of claim 100, wherein the step of using speech recognition to control the shot clock includes starting the shot clock after interpreting speech of a chair umpire as an announced score following completion of a point in a tennis match.
102. The method of claim 99, wherein the step of actively controlling the shot clock comprises detecting a predetermined sound above a threshold decibel level.
103. The method of claim 102, wherein the predetermined sound is a voice of a chair umpire.
104. The method of claim 103, wherein the step of detecting the voice of the chair umpire only occurs within a predetermined time following completion of a point in a tennis match and the score has been electronically recorded by the chair umpire.
105. The method of any one of claims 99 to 104, wherein pressing the button also generates a start of point signal indicating that a point in a match has started.
106. The method of claim 105, wherein, in response to the button being pressed, the shot clock resets.
107. The method of anyone of claims 99 to 106, wherein the shot clock is remote from the handset and the tablet and is situated adjacent a tennis court.
108. The method of any one of claims 99 to 107, further comprising: measuring a force associated with a net extending across a tennis court, and wherein the indicating step occurs when the force meets or exceeds a threshold force during a short duration.
109. The method of claim 108, wherein the threshold force is based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve.
110. The method of any one of claims 99 to 109, wherein the indicating step occurs following a perturbation of the tennis net.
111. The method of any one of claims 99 to 110, wherein the step of actively controlling the shot clock includes using a facial or hand gesture.
112. A system, comprising: an indicator configured to express that an impact between a ball and a tennis net has occurred; and a button which, when pressed, arms a let detection function, wherein the indicator is only operable when the let detection function is armed; and an interface permitting a user to actively control of a shot clock in order to help enforce a time limit imposed upon a player at various stages of a tennis match, wherein the interface does not include a digital or physical button.
113. The system of claim 112, wherein the interface is a microphone mounted on or adjacent a chair of a chair umpire.
114. The system of claim 112, wherein a voice command device in communication with the microphone is configured to generate a signal which starts the shot clock in response to a chair umpire speaking a score of a tennis match into the microphone following a point in the tennis match.
115. The system of claim 114, wherein the voice command device is a tablet.
116. The system of claim 115, further comprising a handset connected to the tablet.
117. The system of claim 112, wherein the interface is a camera configured to acquire images indicative of a hand or facial gesture of a chair umpire.
118. The system of claim 112, wherein the interface is a sensor screen on the handset or additional handset that triggers the shot clock by either a motion over the screen or by physically touching the screen
119. The system of claim 113, wherein the shot clock is started in response to the voice of the umpire speaking into the microphone only within a predetermined time following completion of a point in a tennis match and the score has been electronically recorded by the chair umpire.
120. The system of any one of claims 112 to 119, wherein the button configured to arm the let detection function is on the handset.
121. The system of claim 120, wherein the button is configured to generate a start of point signal.
122. The system of claim 121, wherein, in response to the button being pressed, the shot clock is configured to reset.
123. The system of any one of claims 112 to 122, wherein: the indicator is configured to express that the impact has occurred when a force associated with the net exceeds a threshold force during a short duration, and the threshold force is based on a fingerprint, and the fingerprint is a unique sharp spike in an output of a force measuring device during the short duration and is indicative of an impact between a ball and a net during a serve.