Baseball Prospectus Glossary

According to Jason Parks, #want is the manifestation of human desire and physical yield; when the yearning for perfection becomes visible to the naked eye.

The difference in a team's playoff odds from yesterday.

The 1-day injury risk is a part of the CHIPPER injury projection system. It assesses how likely it is that a player will miss one or more days due to injury.

Associated colors represent the probability of risk: green for low probability, yellow for moderate, and red for high.

The 10-Year Forecast is a player's weighted mean PECOTA forecast, taken over his next 10 seasons.

The 15-day injury risk is a part of the CHIPPER injury projection system. It assesses how likely it is that a player will miss 15 or more days due to injury.

Associated colors represent the probability of risk: green for low probability, yellow for moderate, and red for high.

For hitters: Singles

For pitchers: Singles Allowed

For positions: First Baseman

For hitters: Doubles
For pitchers: Doubles Allowed
For positions: Second Baseman

The 30-day injury risk is a part of the CHIPPER injury projection system. It assesses how likely a player will miss 30 or more days due to injury.

Associated colors represent the probability of risk: green for low probability, yellow for moderate, and red for high.

For hitters: Triples
For pitchers: Triples Allowed
For positions: Third Baseman

A player capable of playing the four corner positions: first base, third base, right field and left field.

The difference in a team's playoff odds from seven days ago.

Assists

According to the MLB offical rules, an assist is "credited to a fielder whose action contributes to a runner being put out."

Air Advancement Opportunities

Number of times a player was involved in one of the following situations:

• Runner on first with second and third unoccupied, less than two outs, a line drive, pop-up, or fly ball is caught by an outfielder
• Runner on second but not third, less than two outs, a line drive, pop-up, or fly ball is caught by an outfielder
• Runner on third with other bases optionally occupied, less than two outs, a line drive, pop-up, or fly ball is caught by an outfielder

At-bats

Official plate appearances where the batter doesn't walk, get hit by a pitch, hit a recognized sacrifice or is interfered with by the catcher.

the number of passed balls and wild pitches allowed by the catcher

the number of passed balls and wild pitches allowed by the catcher

the number of strikes the catcher actually received

the number of strikes the catcher actually received

Adjusted Equivalent Runs: The number of equivalent runs scored by a team, adjusted for the quality of their opponents' pitching and defense.

Clay Davenport includes a brief explanation of this concept in this article on third-order wins.

Adjusted Equivalent Runs Allowed: The number of equivalent runs allowed by a team, adjusted for the quality of their opponents' offense.

Clay Davenport includes a brief explanation of this concept in this article on third-order wins.

AGL stands for Average Games Lost and is found in Collateral Damage Daily.

Adjusted Hit List Factor: Adjusts Hit List Factor (HLF) for quality of league.

The league quality adjustment is based on historical performance of batters against pitchers from the various leagues (primarily in interleague play, but also players who switch teams midseason).

Adjusted Pitching Runs: Measures pitching production in terms of runs prevented above average.

A method introduced by Pete Palmer in the book "Total Baseball" to calculate a pitcher's value in runs above average. It is calculated differently here than in "Total Baseball."

Formula:

APR = L * IP - R / pf(P)

• L: Average number of runs per inning pitched in the league
• IP: Innings Pitched
• R: Runs Allowed
• pf(P): park factor for the player's home park P.

This measure was introduced by Michael Wolverton here.

Adjusted Pitching Wins. Thorn and Palmer's method for calculating a starter's value in wins. Included for comparison with SNVA. APW values are calculated using total runs allowed instead of earned runs allowed.

Michael Wolverton talks about adjusted pitching wins here.

Adjusted Runs Prevented: Runs prevented from scoring for relief pitchers based on the Run Expectancy Matrix.

Measures a reliever's contribution using the Run Expectancy Matrix. For each base-out situation, the Run Expectancy Matrix tells us how many runs are expected to score in that inning.

Formula:

ARP = (ER(sS,P) - ER(sF,P) + IF*ER(s0,P) - R) / pe(P)

• ER(s,P): The expected number of runs that will score in the remainder of an inning starting in base-out state "s" in park "P"
• sS: The base-out state when the reliever entered the game
• sF: The base-out state when the reliever left the game
• IF: The number of innings the reliever finished
• s0: A special state for the beginning of an inning which is distinct from the state for no outs, none on.
• R: The number of runs that scored while the reliever was in the game
• pe(P): The park effect for park "P"

This method was introduced by Michael Wolverton and further explained by Derek Jacques.

ATD is the average TAv lost due to the injuries and is found in Collateral Damage Daily.

Hitters: Batting average
Pitchers: Batting average allowed

Average number of pitches per start

Average Pitcher Abuse Points per game started

The odds of a team reaching the Division Series round.

To find Adj. Playoff Pct, we multiply the team's Wild Card percentage by the odds of them winning the Wild Card play-in game, and add the odds of them winning their division.

Adjusted Games: The estimated number of real, nine-inning games played at this position.

The Adjusted Standings offer insight into a team's record.

While a team's actual record is presented on the Adjusted Standings page, so are the team's 1st, 2nd, and 3rd order winning percentages, as well as the deltas between the team's actual record and those records, and how those teams fare via the Hit List Factor. The Adjusted Standings page differs in utility from the Playoff Odds Report or Team Audit Standings in that it provides a quick reference for whether a team is playing over or under its record based on statistical indicators.

Statistics that have been adjusted for all-time have all of the adjustments for a single season, plus two more. One adjustment normalizes the average fielding numbers over time. Historically, the fielding share of total defense has been diminishing with time - more walks, more strikeouts, and more home runs means less work for fielders. In the single-season adjustments, fielders from before WWII have a lot more value than fielders today; the all-time adjustments have attempted to remove that temporal trend. The second adjustment is for league difficulty. League quality has generally increased with time. Each league has been rated for difficulty and compared to a trend line defined by the post-integration National League. In addition to the adjustments for season, an adjustment is made for league difficulty.

Statistics that have been adjusted for a single season are the best stats to use when you are only interested in that one season. In these, adjustments have been made to account for the home park and for the offensive level of the league as a whole. Hitters have an adjustment for not having to face their own team's pitchers; pitchers have a similar adjustment for not having to face their own hitters. Hitters in the AL since 1973 have a disadvantage in these statistics, since the league average is artificially inflated by the use of the DH and no adjustment is made for that.

A player's "seasonal age" or "baseball age" is his age as of July 1st that season.

The percent chance that a player's playing opportunities will decrease by at least 50 percent relative to his baseline playing time forecast. For hitters, playing opportunities are measured by plate appearances and for pitchers, they are measured by opposing batters faced.

Although it is generally a good indicator of the risk of injury, Attrition Rate will also capture seasons in which playing time decreases due to poor performance or managerial decisions.

Singles per plate appearance

Doubles per plate appearance

Triples per plate appearance

Batting Average on Balls In Play

A pitcher's average on batted balls ending a plate appearance, excluding home runs. Based on the research of Voros McCracken and others, BABIP is mostly a function of a pitcher's defense and luck, rather than persistent skill. Thus, pitchers with abnormally high or low BABIPs are good bets to see their performances regress to the mean. The league average for modern pitcher BABIP is around .300.

Hitter BABIP is much more of a skill, based on how well they are able to hit and place the ball, along with their speed.

Equation:

BABIP = (H - HR) / (AB - K - HR + SF + SH)

Hitters: Base on balls (walks)
Pitchers: Base on balls (walks) allowed

Bases on balls allowed per 9 innings pitched.

Walks per inning pitched

Walk rate: Percentage of plate appearances that result in a walk.

Total expected run value from bequeathed runners (runners who are on base when the pitcher left his games).

Expected runs value from bequeathed runners for which the exiting pitcher is responsible

Bequeathed baserunners of the exiting pitcher prevented from scoring. The difference between expected runs and scored runs.

Bequeathed runners who scored.

Bequeathed runners for which the pitcher is responsible. More simply, the number of runners a pitcher left on base when exiting the game, excluding runners still on base put there by a preceding pitcher.

The number of runners a pitcher left on base when exiting the game who eventually scored.

Batters faced pitching.

Balks.

Not recorded 1876-1880.

Batters Left On Base

pitches the catcher received that could have resulted in a wild pitch or passed ball

pitches the catcher received that could have resulted in a wild pitch or passed ball; this is when runners are on base or a dropped third strike is possible

the run value accumulated from preventing wild pitches and passed balls

the run value accumulated from preventing wild pitches and passed balls (.28 per PB/WP saved)

Batting Park Factor.

BPF is centered around 100, with numbers above and below representing percentage that run-scoring was increased by the mix of parks the batter batted in. For instance, 110 represents 10% above average and 96 represents 4% below average.

BP database ID

Bequeathed baserunners

Bequeathed runs prevented from scoring.

Measures how many more or fewer of the bequeathed baserunners subsequent relievers allowed to score than would be expected from league average performance in those situations. I.e., a positive figure means the following relievers kept more of the bequeathed runners from scoring than expected, negative means more of the runners scored than expected.

Blown Quality Start

Baserunners per nine innings

Formula:

BR9 = (( H + BB + HBP ) / IP ) * 9

Batting Runs Above Average is the number of runs a hitter produces relative to an average hitter, adjusted for park.

Batting Runs Above Average. The number of runs better than a hitter with a .260 EQA (i.e., an average hitter) and the same number of outs; EQR - 5 * OUT * .260^2.5.

Batting runs above average (BRAA), adjusted for league difficulty.

Batting Runs Above Replacement. The number of runs better than a hitter with a .230 EQA and the same number of outs; EQR - 5 * OUT * .230^2.5.

Batting runs above replacement (BRAR), adjusted for league difficulty.

Batting runs above a replacement at the same position. A replacement position player is one with an EQA equal to (230/260) times the average EqA for that position.

Baserunning Runs measures a player's contributions on the basepaths based on activity during the run of play, on stolen base attempts, from tag-up situations, and other advancement opportunities.

Baserunning Runs. Measures the number of runs contributed by a player's advancement on the bases, above what would be expected based on the number and quality of the baserunning opportunities with which the player is presented, park-adjusted and based on a multi-year run expectancy table. BRR is calculated as the sum of various baserunning components: Ground Advancement Runs (GAR), Stolen Base Runs (SBR), Air Advancement Runs (AAR), Hit Advancement Runs (HAR) and Other Advancement Runs (OAR).

Here is an example of the Baserunning Runs spectrum based on the 2011 season:

Excellent - Ian Kinsler 11.6
Great - Coco Crisp 4.3
Average - Bobby Abreu 0.0
Poor - Casey Kotchman -4.4
Horrendous - Ryan Howard -9.4


Note: Credit/blame for Double plays is not ascribed to either batter or runner(s) via BRR. Hence Manny Machado can lead MLB in GIDP in 2018 yet have almost +1 BRR. Or Tommy Pham with 18 GIDP in 570 PA and almost +5 BRR.

Batting Runs above Replacement for the Position. This is, essentially, the equivalent average version of VORP. It is the number of equivalent runs this player had above what a replacement level player with the same mix of positions.

Blown Saves.

Occurs when a pitcher comes into the game in a save situation and surrenders the lead at any point during his appearance. The runners that score may be inherited from another pitcher, but the blown save is still charged to the pitcher who allowed them to score. Assigned for both closers and middle relievers.

Value over Replacement Player (VORP) as a batter, in runs. This is equal to VORP for batters who did not pitch.

Wins Above Replacement Player (WARP) gained as a non-pitcher. This includes hitting and fielding.

Percentage of pitches thrown for balls.

Number of balls seen (batter) or thrown (pitcher)

Refers to the Baserunner State combined with the number of outs in the current half inning, used to calculate Win Expectancy. For example, '2-103' indicates two outs with runners on first and third.

The Baseline forecast, although it does not appear here, is a crucial intermediate step in creating a player's forecast. The Baseline developed based on the player's previous three seasons of performance. Both major league and (translated) minor league performances are considered.

The Baseline forecast is also significant in that it attempts to remove luck from a forecast line. For example, a player who hit .310, but with a poor batting eye and unimpressive speed indicators, is probably not really a .310 hitter. It's more likely that he's a .290 hitter who had a few balls bounce his way, and the Baseline attempts to correct for this.

Indication of who is on base, used to calculate Win Expectancy. An unoccupied base is designated with a '0', and an occupied base is designated with the number of the base (1=first base, 2=second base, 3= third base). All bases are represented by a three-digit string. For example, 000=bases empty, while 103=runners on first and third.

The number of runs a player has batted in other than himself.

BATTED_IN=RBI-HR

On the custom statistic reports, the Batter column is a unique identification number for the respective batter.

Batting average; hits divided by at-bats. In PECOTA, Batting Average is one of five primary production metrics used in identifying a hitter's comparables. It is defined as H/AB.

Bequeathed runs prevented from scoring. Measures how many more or fewer of the bequeathed baserunners subsequent relievers allowed to score than would be expected from league average performance in those situations. I.e., a positive figure means the following relievers kept more of the bequeathed runners from scoring than expected, negative means more of the runners scored than expected.

Bequeathed baserunners. More simply, the number of runners a pitcher left on base when exiting the game, including runners still on base put there by a preceding pitcher.

A measure of the relative volatility of a player's EqA or EqERA forecast, as determined from his comparables. The Beta for an average major league player is 1.00; players with Beta's higher than 1.00 have more volatile forecasts than others ("riskier"), while Betas lower than 1.00 represent less volatile forecasts ("less risky").

Betas are adjusted for the amount of playing time that a player is expected to receive. Thus, a player's Beta will not be higher simply because he's expected to receive less playing time (as a relief pitcher might as compared with a starter, for example), which naturally produces more variance because of higher sample sizes. Betas may be unreliable for players with few appropriate comparables.

Runs a catcher saves (usually over the course of a season), based on EPAA.

There's a factor for each year-level combination which varies from less than 0.20 to more than 0.33, averaging around 0.27. This factor is multiplied times EPAA times EPAA chances (Blocking Chances) to get EPAA Runs (or Blocking Runs).

Used to identify on which body part an injury occurred.

Breakout Rate is the percent chance that a player's production will improve by at least 20 percent relative to the weighted average of his performance over his most recent seasons.

The percent chance that a player’s production (measured by RA for pitchers, and True Average for hitters) will improve by at least 20 percent relative to the weighted average of his performance over his most recent seasons.

Every player of the same age in our database (historically) is assigned a similarity score to the player in question. For each such similar player, a "baseline" value is projected for runs allowed based on past performance and standard aging curves. The weighted average of "1" or "0" for each of these similar players is taken, where "1" is used each time a comp player accomplished the goal in questionβ€”improving his run prevention or True Average by 20 percent.

Break:Tunnel Ratio - This stat shows us the ratio of post-tunnel break to the differential of pitches at the Tunnel Point. The idea here is that having a large ratio between pitches means that the pitches are either tightly clustered at the hitter's decision-making point or the pitches are separating a lot after the hitter has selected a location to swing at. Either way a pitcher's ratio can be large.

Break:Tunnel Ratio - This stat shows us the ratio of post-tunnel break to the differential of pitches at the Tunnel Point. The idea here is that having a large ratio between pitches means that the pitches are either tightly clustered at the hitter's decision-making point or the pitches are separating a lot after the hitter has selected a location to swing at. Either way a pitcher's ratio can be large.

A category 1 start is a start in which the pitcher throws 100 pitches or less.

A category 2 start is a start in which the pitcher throws 101-109 pitches.

A category 3 start is a start in which the pitcher throws 110-121 pitches.

A category 4 start is a start in which the pitcher throws 122-132 pitches.

A category 5 start is a start in which the pitcher throws 133 or more pitches.

Complete Games.

Comprehensive Health Index [of] Pitchers [and] Players [with] Evaluative Results

The CHIPPER injury forecaster projects injury risk for players at three different levels: 1+ games missed, 15+ games missed, and 30+ games missed. Green is low risk, yellow moderate, and red high. This differentiation of time missed allows a more detailed look at the specific risks individual players are facing. Check out Dan Turkenkopf's introduction for more on the CHIPPER methodology.

Contact rate: percentage of pitches swung at on which contact is made (includes foul balls).

2012 Hitter Examples

Very low: Cody Ransom, 0.6229
Low: Cody Ross, 0.7575
Around average: Cameron Maybin, 0.8015
High: Asdrubal Cabrera, 0.8411
Very high: Chris Getz, 0.9308

2012 Pitcher Examples

Very low: Craig Kimbrel, 0.6095
Low: Craig Breslow, 0.7606
Around average: Matt Cain, 0.7973
High: Chris Tillman, 0.8186
Very high: Bartolo Colon, 0.9043

Caught Stealing

CS are not available for the NL from 1876-1950 (except for 1915, 1920-25, and some players for 1916), in the AL from 1901-19 (except 1914-15 and some 1916 players), and are not available at all for the AA, UA, PL, or FL. Surprisingly, they are available for the NA. In catcher's fielding, not available prior to 1978.

This stat tells us the likelihood that a particular pitch will be called a strike based on a variety of factors. CS Prob is calculated on every pitch thrown by a pitcher. CS Prob is a proxy for control, or the ability of a pitcher to throw strikes.

This stat tells us the likelihood that a particular pitch will be called a strike based on a variety of factors. CS Prob is calculated on every pitch thrown by a pitcher. CS Prob is a proxy for control, or the ability of a pitcher to throw strikes.

The number of team caught stealings accumulated by runners on first base.

The number of team caught stealings accumulated by runners on second base.

The number of team caught stealings accumulated by runners on third base.

Career Path Analysis is the name for a chart on a player's PECOTA card. The solid, curved lines represent a player's VORP at his 90th, 75th, 60th, 50th (Median), 40th, 25th and 10th percentile levels of performance over the course of his next five seasons. All of these lines appear in BLUE, except for a player's Median/50th percentile forecast, which appears in RED.

Collapse Rate is the percent chance that a position player's true runs produced per PA will decline by at least 25 percent relative to his baseline performance over his past three seasons.

Collapse Rate can sometimes be counterintuitive for players who have already experienced a radical change in their performance levels.

Comparable Players are generated by taking a player's baseline projection and finding players with the same age and similar contact, power on contact, walks, and strikeout rates, as well s similar height, weight, handedness, and position (or start/relief split for pitchers).

It's also important to note that established major leaguers are compared to other major leaguers only, while minor-league players may be compared to major-league or minor-league players, with PECOTA strongly preferring the latter. All comparables represent a snapshot of how the listed player was performing at the same age as the current player, so if a 23- year-old hitter is compared to Miguel Tejada, he's actually being compared to a 23-year-old Tejada, not the decrepit Giants version of Tejada, nor to Tejada's career as a whole.

Comparable Year represents the season analogous to the current projected year for a comparable player. For example, if Dick Allen is listed as a comparable, and the year listed next to his name is 1974, Allen's 1974 is used as a component of the player's forecast. It also indicates that Allen's Baseline performance entering into the 1974 season was similar to the Baseline performance of the player in question.

PECOTA constructs a 182-day interval on either side of a player's birthdate in order to match ages; this method is more precise than the Bill James similarity scores, which use a player's age as of July 1.

The Compensation Browser allows users to access salary and payroll data, as well as the Cot's Contracts website.

Difference between actual wins and W1. A positive number means the team has won more games than expected from their statistics.

Difference between actual wins and W2. A positive number means the team has won more games than expected from their statistics.

Difference between actual wins and W3. A positive number means the team has won more games than expected from their statistics.

Delta-hits. The number of hits above or below what would be expected for this pitcher.

Defense-adjusted ERA. Not to be confused with Voros McCracken's Defense-Neutral ERA. Based on the PRAA, DERA is intended to be a defense-independent version of the NRA. As with that statistic, 4.50 is average. Note that if DERA is higher than NRA, you can safely assume he pitched in front of an above-average defense.

How much a pitcher is underrated by Adjusted Pitching Runs (DIFF = ARP - APR).

Days Missed Per Injury. The average number of days missed per team injury.

Double plays, turned or hit into.

The percent of the time the double play opportunities (DP_OPPS) were converted into double plays (DP)

The number of double play opportunities (defined as less than two outs with runner(s) on first, first and second, or first second and third).

DRA needs a week or two to get started each year but is up and running for good by May, and often well before.

DRA is BP's flagship pitcher run estimator. It estimates the rate at which a pitcher "deserved" to give up runs, and includes estimates for the uncertainty around that rate.

Deserved Run Average (DRA) uses a collection of multilevel models to estimate the most likely contributions of pitchers to the run-scoring that occurs around them. Unlike other component metrics, DRA considers (and adjusts) for park, opponent, and, when helpful, framing, temperature, and pitch type as well. DRA achieves significant improved reliability over both raw pitcher statistics (like ERA) and other pitcher run estimators. DRA estimates include uncertainty estimates, making it easier to compare players to one another and to appreciate the stability of DRA's estimates, even early on in the season. In general, a pitcher's DRA, plus or minus one standard deviation (DRA_SD) encompasses at least 70% of the "true" DRA values for that pitcher.

DRA- (pronounced "DRA Minus" and sometimes written as "DRA-Minus") rates pitchers by how well they compared to their peers rather than by an amount of predicted runs allowed in a given season. Knowledgeable baseball fans are familiar with statistics like this. Common examples include FIP-, ERA-, and wRC+. The formula for DRA-Minus is DRA / DRA_mean * 100

DRA-Minus ("DRA–") As noted above, we've received multiple requests for a "minus" version of DRA, something that rates pitchers by how well they compared to their peers rather than by an amount of predicted runs allowed in a given season. Knowledgeable baseball fans are familiar with statistics like this. Common examples include wRC+ and ERA-. The idea is to put an average player for each season at 100, and then rate players by how much they vary from the average. By rating every pitcher by how good (or poor) he was by comparison to his peers, we can make fairer comparisons across different seasons and different eras. These comparisons aren't perfect: We can't make baseball 50 years ago more diverse or force today's players to endure the conditions of 50 years ago, but metrics like DRA– allow comparisons of pitchers across seasons and eras to be much more meaningful.

The formula for DRA-Minus is DRA / DRA_mean * 100

Unlike cFIP (which considers only the three true outcomes), DRA– will not have a forced standard deviation. The two numbers (which are otherwise both scaled to 100) can still be compared, but be mindful of that distinction. For both cFIP and DRA–, lower is better.

See: http://www.baseballprospectus.com/article.php?articleid=26613

Pitcher WARP computed using DRA instead of FAIR_RA.

Replacement level used for a particular pitcher in computing WARP based on DRA.

Type the definition of the term here, or leave the text as it is if you don't want to add a new term.

Number of runs saved - compared to replacement level - by this pitcher, taking into account DRA, DRA_REP_RA, and innings pitched.

Type the definition of the term here, or leave the text as it is if you don't want to add a new term.

DRC+ is the Deserved Runs Created for a batter, scaled to a 100-based index. It tells us how valuable a player's offensive contribution is by assigning appropriate credit to plate appearance outcomes and applying contextual factors like park effects and opponent quality.

Learn more about DRC+ at our DRC+ Showcase page.

Traditional metrics compromise accuracy in two ways: (1) they summarize play outcomes in which players were involved, not player contributions to those outcomes; and (2) they treat all outcomes as equally likely to be driven by the player, even though no one believes that is true.

DRC+ addresses the first problem by rejecting the assumption that play outcomes equal player contributions, and forces players to demonstrate a consistent ability to generate those outcomes over time to get full credit for them. DRC+ addresses the second problem by recognizing that certain outcomes (walks, strikeouts) are more attributable to player skill than others (singles, triples). DRC+ gives more weight to extreme performances in the former (because they are probably meaningful) and less weight to extreme performances in the latter (because they are less likely to be meaningful). By addressing these two deficiencies in existing metrics, DRC+ ends up being substantially more reliable and predictive than any other baseball hitting metric. (The PA-level opponent and park adjustments don’t hurt either). The Top 15 undervalued players are not β€œundervalued” in the sense that they are hidden Hall of Famers; they get undervalued by OPS / wOBA / SLG / wRC+ / whatever because those metrics do not weight each event by the likelihood it was driven by the player himself, as opposed to random variance.

A player like Alberto Callaspo has somewhat extreme numbers in metrics DRC+ considers uniquely likely to be driven by the player: healthy walk rates and exceptionally low strikeout rates. Callaspo saved runs every year, on average, by striking out very infrequently. He was above average in walks for a while, although not every season. One consequence of not striking out so much is that he was hitting more singles, and consistently gets credit for hitting more singles than average. The point isn’t that Callaspo is some great player: it is that DRC+ better understands how β€œreal” his contributions were than other metrics, because the latter make no effort to distinguish the various aspects of his game. It brings the same, more sophisticated perspective to other players also.

Deserved Runs Above Average - Runs above average for a hitter (RAA) based on the DRC+ model.

Deserved Runs Above Average - Runs above average for a hitter (RAA) based on the DRC+ model. This is used in the computation of Batter WARP. An introduction to the DRC+ statistic is here: https://www.baseballprospectus.com/news/article/45432/why-drc/

Deserved Runs Prevented (DRP) is BP’s metric for assessing fielder performance.

DRP is a top-level statistic that collects and sums the various ways that a defender can impact a play. This equation is generally dominated by the player’s range (RDA, or Range Defense Added), outfield assists (OFA), the rate at which defenders prevent baserunners from advancing (BRR_ARM), and the collected contributions of catcher defense (CDA, or Catcher Defense Added).

A player's defensive wins above replacement, as listed on his PECOTA card, and accounting for the value of his position and the quality of his defense. Analagous to FRAR.

Days eXpected Lost -- used as an estimate of how many days a player is expected to miss due to an injury or illness. For starters, five days equals one start.

The date the player returned from the injury.

The date the player suffered the injury.

How many days the player missed due to the injury.

Defensive Efficiency = 1- (H-HR)/(AB-SO-HR+SH+SF)

Def Eff, or Defensive Efficiency, is the rate at which balls put into play are converted into outs by a team's defense. Def Eff can be approximated with (1 - BABIP), if all you have is BABIP, but a team's actual Def Eff is computed with

1 - ( H - HR ) / ( AB - SO - HR + SH + SF )

the Team Audit Standings use the latter formula.

Alternately, it will be seen some places (including some past editions of Baseball Prospectus) computed as 1 - ((H + ROE - HR) / (PA - BB - SO - HBP - HR)), which comes out slightly lower in most instances.

Here is an example of the Defensive Efficiency spectrum based on the 2011 season:

Excellent - Tampa Bay .735
Great - Texas .722
Average - Toronto .710
Poor - Pittsburgh .700
Horrendous - Minnesota .693

Defense, as listed in a player's PECOTA card, provides the player's number of defensive games played, primary position, and fielding runs above average (FRAA) with a given team in a given season.

The number of hits above or below average for this pitcher, based on his own number of balls in play and his team's rate of hits (minus home runs) per ball in play; (H-HR) - BIP * (team (H-HR)/BIP). Essentially, the Voros McCracken number. For a team, Delta-H should be zero. Positive numbers signify more hits allowed than expected ("bad luck," if you believe pitchers have nothing to do with the outcome of a BIP), negative numbers mean fewer hits than expected ("good luck").

The number of runs, more or less, that a pitcher allowed, compared to his statistics. The pitcher's statistics (such as hits, walks, home runs) are run through a modified version of the equivalent runs formula to get estimated runs. Again, positive is "bad luck," negative is "good luck."

The number of wins, more or less, that a pitcher won, compared to estimated wins. Estimated wins are derived from the pitcher's actual runs allowed and team average run scoring. Here, a positive number is "good luck," negative is "bad luck."

The Depth Charts page compiles pertinent team data based on PECOTA projections and the latest Depth Charts update.

Users can access each team's individual depth chart as well as get an overview of how the teams are expected to perform in wins, losses, runs scored, runs allowed, and other vital statistical categories.

Diagnostics are a series of metrics designed to estimate the probability of certain types of changes in production and playing time; see the individual entries for additional detail.

Difference between RS/G and RA/G. A positive number means a team is scoring more runs than they're allowing on average.

Plate Differential - This statistic shows how far apart back-to-back pitches end up at home plate, roughly where the batter would contact the ball. This includes differentiation generated by pitch break and trajectory of the ball (which includes factors like gravity, arm angle at release, etc.).

Plate Differential - This statistic shows how far apart back-to-back pitches end up at home plate, roughly where the batter would contact the ball. This includes differentiation generated by pitch break and trajectory of the ball (which includes factors like gravity, arm angle at release, etc.).

Release Differential - When analyzing pitchers, we often talk about consistency in their release point, pointing to scatter plots to see if things look effectively bunched or not. This stat measures the average variation between back-to-back pitches at release.

Release Differential - When analyzing pitchers, we often talk about consistency in their release point, pointing to scatter plots to see if things look effectively bunched or not. This stat measures the average variation between back-to-back pitches at release.

Tunnel Differential - This statistic tells you how far apart two pitches are at the Tunnel Pointβ€”the point during their flight when the hitter must make a decision about whether to swing or not (roughly 175 milliseconds before contact).

Tunnel Differential - This statistic tells you how far apart two pitches are at the Tunnel Pointβ€”the point during their flight when the hitter must make a decision about whether to swing or not (roughly 175 milliseconds before contact).

Each league has been given a difficulty level, based on the performance of players in that league compared to the same players' performance in other seasons. The reference difficulty level was defined by the trend line of the National League from 1947 to 2002, and extended backwards to 1871. The difficulty adjustment is the ratio between the actual difficulty level and the reference level.

The percentage of times a team wins their division in the simulated seasons.

Drop Rate is the percent chance that a player will not receive any major league plate appearances in a given season, based on comparables who disappear from the dataset entirely. Because of the conventions PECOTA uses in selecting comparables, the Drop Rate is always assumed to be zero for the current year, but it is an important consideration in a hitter's Five-Year Forecast.

Errors.

Expected loss record for the pitcher, based on how often pitchers with the same innings pitched and runs allowed earned a win or loss historically (this differs from how it was computed, which was a more complicated, theoretical calculation).

Expected win record for the pitcher, based on how often pitchers with the same innings pitched and runs allowed earned a win or loss historically (this differs from how it was computed, which was a more complicated, theoretical calculation).

Expected winning percentage for the pitcher, based on how often a pitcher with the same innings pitched and runs allowed in each individual game earned a win or loss historically in the modern era (1972-present).

Rate version of END_GAME: percentage of the player's plate appearances that were the last PA of the game.

Number of times the player had the last plate appearance of the game.

EPAA - Errant Pitches Above Average - is the official name for Passed Balls and Wild Pitches above average. Please click here for details: Errant Pitches Above Average

Unfortunately, Passed Balls or Wild Pitches Above Average would be quite a mouthful. Again, we're trying out a new term to see if it is easier to communicate these concepts. We're going to call these events Errant Pitches. The statistic that compares pitchers and catchers in these events is called Errant Pitches Above Average, or EPAA.

(from http://bbp.cx/a/26195)

Under baseball’s scoring rules, a wild pitch is assigned when a pitcher throws a pitch that is deemed too difficult for a catcher to control with ordinary effort, thereby allowing a baserunner (including a batter, on a third strike) to advance a base. A passed ball is assigned when a pitcher throws a pitch that a catcher ought to have controlled with ordinary effort, but which nonetheless gets away, also allowing a baserunner to move up a base. The difference between a wild pitch and a passed ball, like that of the β€œearned” run, is at the discretion of the official scorer. Because there can be inconsistency in applying these categories, we prefer to consider them together.

Last year, Dan Brooks and Harry Pavlidis introduced a regressed probabilistic model that combined Harry’s pitch classifications from PitchInfo with a With or Without You (WOWY) approach. RPM-WOWY measured pitchers and catchers on the number and quality of passed balls or wild pitches (PBWP) experienced while they were involved in the game.

Not surprisingly, we have updated this approach to a mixed model as well. Unfortunately, Passed Balls or Wild Pitches Above Average would be quite a mouthful. Again, we’re trying out a new term to see if it is easier to communicate these concepts. We’re going to call these events Errant Pitches. The statistic that compares pitchers and catchers in these events is called Errant Pitches Above Average, or EPAA.

Unfortunately, the mixed model only works for us from 2008 forward, which is when PITCHf/x data became available. Before that time, we will rely solely on WOWY to measure PBWP, which is when pitch counts were first tracked officially. For the time being, we won’t calculate EPAA before 1988 at all, and it will not play a role in calculating pitcher DRA for those seasons.

But, from 2008 through 2014, and going forward, here are the factors that EPAA considers:

• The identity of the pitcher;
• The identity of the catcher;
• The likelihood of the pitch being an Errant Pitch, based on location and type of pitch, courtesy of PitchInfo classifications.

Errant Pitches, as you can see, has a much smaller list of relevant factors than our other statistics.

In 2014, the pitchers with the best (most negative) EPAA scores were:

And the pitchers our model said were most likely to generate a troublesome pitch were:

Runs a catcher saves (usually over the course of a season), based on EPAA.

There's a factor for each year-level combination which varies from less than 0.20 to more than 0.33, averaging around 0.27. This factor is multiplied times EPAA times EPAA chances (Blocking Chances) to get EPAA Runs (or Blocking Runs).

Also known as a BSP chart, an acronym for bloodstain spatter pattern, which these graphs seem to bear an eerie resemblance toward. The BSP charts plot a rate performance statistic (EqA or EqERA) on the one axis and playing time on the other (PA or IP). Each of the diamonds you see represents the performance implied by one of a player's comparables; the higher the similarity score for that comparable, the larger the size of the diamond. There is also an area of the chart shaded in a yellow color; this is the ‘golden zone' of performance in which a player both performs well (an EqA of .300 or higher) and remains in the lineup frequently (at least 500 plate appearances). Pitchers actually have two golden zones, one each for roles as starting pitchers and relievers.

Earned Runs.

Earned Run Average. Earned runs, divided by innings pitched, multiplied by nine.

In PECOTA projections, the ERA Distribution chart displays a pitcher's ERA forecast at various levels of probability. It progresses in sequential intervals of five percentage points, ranging from a pitcher's 95th percentile forecast on the left, to his 5th percentile forecast on the right.

In addition to the probability distribution for a given pitcher, which appears in blue, the chart also includes a normal distribution on ERA for all pitchers in the league, as adjusted to the player's current park and league context ("Norm"), and a dashed line representing the performance of a replacement level pitcher ("Replace").

Expected Return Date: An estimate of the date a player is expected to return to the lineup/rotation based on the current information. A player listed as "10/4" is done for the season; October 4th is the final day of the regular season.

Expected runs scored with zero outs

Expected runs scored with one out

Expected runs scored with two outs

Run differential (team at bat - team in field)

the difference between actual and predicted strikes received by the catcher

the difference between actual and predicted strikes received by the catcher

Equivalent Average. A measure of total offensive value per out, with corrections for league offensive level, home park, and team pitching. EQA considers batting as well as baserunning, but not the value of a position player's defense. The EqA adjusted for all-time also has a correction for league difficulty. The scale is deliberately set to approximate that of batting average. League average EqA is always equal to .260.

EqA is derived from Raw EqA, which is

RawEqA =(H+TB+1.5*(BB+HBP+SB)+SH+SF-IBB/2)/(AB+BB+HBP+SH+SF+CS+SB)

Any variables which are either missing or which you don't want to use can simply be ignored (be sure you ignore it for both the individual and league, though). You'll also need to calculate the RawEqa for the entire league (LgEqA).

Convert RawEqA into EqR, taking into account the league EqA LgEqA, league runs per plate appearance, the park factor PF, an adjustment pitadj for not having to face your own team's pitchers, and the difficulty rating. Again, you can ignore some of these as the situation requires. xmul can simply be called "2", while the PF, diffic, and pitadj can be set to "1".

xmul=2*(.125/PF/Lg(R/PA)/pitadj)

EQAADJ=xmul*(RawEqa/LgEqa)* ((1+1/diffic)/2) + (1-xmul)

UEQR=EQAADJ*PA*Lg(R/PA)

To get the final, fully adjusted EqA, we need to place this into a team environment.

This is an average team:

AVGTM=Lg(R/Out)*Lg(Outs/game)*PF*Games*(DH adjustment)

The DH adjustment is for playing in a league with a DH. "Games" is the number of games played by this player.

Replacing one player on the average team with our test subject:

TMPLUS=AVGTM+UEQR-OUT*Lg(R/Out)*DH*PF

Get pythagorean exponent

pyexp=((TMPLUS+AVGTM)/Games)**.285

Calculate win percentage

WINPCT=((TMPLUS/AVGTM)**pyexp)/(1+(TMPLUS/AVGTM)**pyexp)

Convert into adjusted space, where the Pythagorean exponent is set to 2.

NEWTM=(WINPCT/(1-WINPCT))**(1/2)

Fully adjusted EqR:

EQR=.17235*((NEWTM-1)*27.*Games + Outs)

Fully adjusted EqA

EQA= (EQR/5/Outs)** 0.4

Equivalent Average, as taken from the Davenport Translation (DT) Player Cards. EqA1 is EqA adjusted for the season in which the performance occurred, as opposed to EqA2, which is adjusted for comparisons across multiple seasons or eras. For example, if you wanted to compare Albert Pujols's 2008 performance against those of other players in the 2008 season, you would reference his EqA1; if you wanted to compare Pujols's 2008 against Lou Gehrig's seasons in the 1920s and 30s, you would reference Pujols's and Gehrig's respective EqA2s.

Air Advancement Runs. The number of theoretical runs contributed by a baserunner or baserunners above what would be expected given the number and quality of their baserunning opportunities. AAR is based on a multi-year Run Expectancy matrix, is park adjusted, and considers the following scenarios:

• Runner on first with second and third unoccupied, less than two outs, a line drive, pop-up, or fly ball is caught by an outfielder
• Runner on second but not third, less than two outs, a line drive, pop-up, or fly ball is caught by an outfielder
• Runner on third with other bases optionally occupied, less than two outs, a line drive, pop-up, or fly ball is caught by an outfielder

Here is an example of the Air Advancement Runs spectrum based on the 2011 season:

Excellent - Alex Gordon 2.68
Great - Robinson Cano 1.21
Average - Brian Bogusevic 0.00
Poor - Yorvit Torrealba -1.43
Horrendous - Adrian Gonzalez -2.28

Equivalent Batting Average, sometimes also referred to as Translated or Normalized Batting Average. This is a player's batting average, adjusted for ballpark, league difficulty, and era, and calibrated to an ideal major league where the overall EqBA is .260. While a major league hitter's equivalent stats should not differ substantially from his actual numbers, a minor league hitter's equivalent stats undergo translation and may differ significantly.

EqBA, or Equivalent Batting Average, is calibrated to an ideal major league with an overall EqBA of .270. While a major league hitter's equivalent stats should not differ substantially from his actual numbers, a minor league hitter's equivalent stats undergo translation and may differ significantly. Equivalent stats also account for park effects.

EqBB9 is calibrated to an ideal major league where EqBB9 = 3.0. While a major league pitcher's equivalent stats should not differ substantially from his actual numbers, a minor league pitcher's equivalent stats undergo translation and may differ significantly. Equivalent stats also adjust for park effects.

EqERA is calibrated to an ideal major league where EqERA = 4.50. While a major league pitcher's equivalent stats should not differ substantially from his actual numbers, a minor league pitcher's equivalent stats undergo translation and may differ significantly. Equivalent stats also adjust for park effects, and the quality of a pitcher's defense. EqERA is conceptually identical to NRA, as used in the DT cards.

Ground Advancement Runs. The number of theoretical runs contributed by a baserunner or baserunners above what would be expected given the number and quality of baserunning opportunities. GAR is based on a multi-year Run Expectancy matrix and considers the following scenarios:

• Runner on first only with less than two outs, ground ball or bunt is hit to an infielder where a hit or an error is not credited
• Runner on second only with less than two outs, ground ball or bunt is hit to an infielder where a hit or an error is not credited
• Runner on third only with less than two outs, ground ball or bunt is hit to an infielder where a hit or an error is not credited

Here is an example of the Ground Advancement Runs spectrum based on the 2011 season:

Excellent - Emilio Bonifacio 6.45
Great - Dexter Fowler 2.98
Average - Roger Bernadina 0.01
Poor - Adrian Gonzalez -1.76
Horrendous - Ryan Howard -3.76

EqH9 is calibrated to an ideal major league where EqH9 = 9.0. While a major league pitcher's equivalent stats should not differ substantially from his actual numbers, a minor league pitcher's equivalent stats undergo translation and may differ significantly. Equivalent stats also adjust for park effects.

Hit Advancement Runs. The number of theoretical runs contributed by a baserunner or baserunners above what would have been expected given the number and quality of opportunities. HAR considers advancement from first on singles, second on singles, and first on doubles and is adjusted for park and based on a multi-year Run Expectancy Matrix.

Here is an example of the Hit Advancement Runs spectrum based on the 2011 season:

Excellent - Dexter Fowler 4.74
Great - Ryan Braun 2.69
Average - James Loney 0.00
Poor - Brett Wallace -2.54
Horrendous - Ryan Howard -5.66

EqHR9 is calibrated to an ideal major league where EqHR9 = 1.0. While a major league pitcher's equivalent stats should not differ substantially from his actual numbers, a minor league pitcher's equivalent stats undergo translation and may differ significantly. Equivalent stats also adjust for park effects.

EqK9 is calibrated to an ideal major league where EqK9 = 6.0. While a major league pitcher's equivalent stats should not differ substantially from his actual numbers, a minor league pitcher's equivalent stats undergo translation and may differ significantly. Equivalent stats also adjust for park effects.

EqMLVr, or Equivalent rate-based Marginal Lineup Value, is calibrated to an ideal major league with an overall EqMLVr of .000. While a major league hitter's equivalent stats should not differ substantially from his actual numbers, a minor league hitter's equivalent stats undergo translation and may differ significantly. Equivalent stats also account for park effects.

Other Advancement Runs. Measures the number of runs contributed by a player's advancement on the bases, above what would be expected based on the number and quality of the baserunning opportunities with which the player is presented. Other Advancement takes into consideration a player's opportunities and advancement on the basepaths due to wild pitches and passed balls. The run value of this advancement is based on a multi-year run expectancy matrix and park-adjusted.

Here is an example of the Other Advancement Runs spectrum based on the 2011 season:

Excellent - Bobby Abreu 0.92
Great - Angel Pagan 0.40
Average - Drew Stubbs 0.05
Poor - Juan Uribe -0.28
Horrendous - Michael Cuddyer -0.72

EqOBP, or Equivalent On Base Percentage, is calibrated to an ideal major league with an overall EqOBP of .340. While a major league hitter's equivalent stats should not differ substantially from his actual numbers, a minor league hitter's equivalent stats undergo translation and may differ significantly. Equivalent stats also account for park effects.

True Runs tells of a player's total offensive contribution in runs.

The formula:
Batting Runs Above Average + Plate Appearances * Average Runs Per Plate Appearance

Equivalent Runs allowed by a team.

Equivalent Stolen Base Runs. The number of theoretical runs contributed by a baserunner or baserunners above what would be expected given the number and quality of their baserunning opportunities. EqSBR is based on a multi-year Run Expectancy matrix and considers both stolen base attempts and pick-offs.

Here is an example of the Stolen Base Runs spectrum based on the 2011 season:

Excellent - Tony Campana 2.82
Great - Dustin Pedroia 1.32
Average - Brandon Phillips -0.01
Poor - Jason Bartlett -1.06
Horrendous - Jon Jay -1.91

EqSLG, or Equivalent Slugging Percentage, is calibrated to an ideal major league with an overall EqSLG of .440. While a major league hitter's equivalent stats should not differ substantially from his actual numbers, a minor league hitter's equivalent stats undergo translation and may differ significantly. Equivalent stats also account for park effects.

The expected win percentage used to run the Monte Carlo sim based on projected strength of team, but exclusive of schedule. Not to be confused with actual expected winning percentage.

For the preseason Playoff Odds Report, this is based on the Depth Chart wins and losses. As the season progresses, a team's observed performance will be incorporated into the expectation as well.

The amount of innings pitched based on the expected outs calculated from a pitchers Fair Runs Average (FRA)

Fair Quality Starts

Uses the same basic framework as a normal quality start - at least 6 innings pitched (or 18 outs) and no more than 3 runs allowed. However, expected runs and outs from fair run average (FRA) are used instead of actual runs and outs.

There is also an adjustment made for a pitcher's level of defensive support, when compared with the seasonal run environment and the park where the game is played.

Fair Run Average in relief appearances.

Fair run average for innings by a starting pitcher. "Fair runs" differ from traditional assignment of runs in that a pitcher who leaves the game is charged with the expected run value of any bequeathed runners left on base, whether or not they eventually score.

Batted balls that were classified as fly balls

Percentage of batted balls that were classified as fly balls

Infield fly balls are excluded from flyball percentage. The percentage is based on the number of batted balls that were classified at all -- batted balls which do not have a known type are omitted.

Fielder's Choice

Fielding Independent Pitching converts a pitcher's three true outcomes into an earned run average-like number. The formula is (13*HR+3*(HBP+BB)-2*K)/IP, plus a constant (usually around 3.2) to put it on the same scale as earned run average.

FIP is a component ERA inspired by the work of Voros McCracken on defense-independent pitching statistics, but has become more widely used because of the ease of computation - it requires only four easily-found box score stats, uses only basic arithmetic operations and has four easily-memorized constants. It was conceived of by both Tom Tango and Clay Dreslough, the latter of who called it Defense-Independent Component ERA.

At Prospectus, we are including hit batters in the walks term. The constant we use is both league and season specific - in other words, a pitcher in the American League will have a different FIP constant than a pitcher in the National League. This differs from the presentation of FIP on sites such as Fangraphs, which use one constant for both leagues in each season.

Here is an example of the Fielding Independent Pitching spectrum based on the 2011 season:

A pitcher's FIP minus his earned run average. Provides a quick look at whether a pitcher is over or underperforming his peripherals (as defined as his strikeouts, walks, home runs, and hit batsmen).

Standard deviation of per-start SNVA for each pitcher. This was previously shown as the variance, and was used to compute the "flakiest" pitchers. Standard deviation is just the square root of the variance, so these are equivalent.

"Front Office Type" - a catchall for any denizen of baseball's various front offices, including but not limited to General Managers, Asst. GMs, scouting or player development, etc.

Fair Run Average (FRA) is scaled to run average and measures not only what a pitcher did, but also when he did it. Adjustments are made for defensive quality.

Fair Run Average differs from FIP in a few ways. While FIP is concerned only with what a pitcher is believed to control-typically strikeouts, walks, and home runs, though Prospectus includes hit batsmen in our FIP calculation-Fair Run Average takes things a step further. Pitchers receive credit for good sequencing, thus rewarding pitchers who seem to work out of jams more often than usual. Fair Run Average also considers batted ball distribution, base-out state, and team defensive quality (as measured by Fielding Runs Above Average).

Here is an example of the Fair Run Average spectrum based on the 2011 season:

Excellent - Clayton Kershaw 2.90
Great - Brandon McCarthy 3.42
Average - Ivan Nova 4.36
Poor - Brett Cecil 5.14
Horrendous - Jake Arrieta 5.88

Fielding Runs Above Average is Prospectus' individual defensive metric created using play-by-play data with adjustments made based on plays made, the expected numbers of plays per position, the handedness of the batter, the park, and base-out states.

The biggest difference between Fielding Runs Above Average and similar defensive metrics comes in the data and philosophy used. Whereas other metrics use zone-based fielding data, Fielding Runs Above Average ignores that data due to the numerous biases present. Fielding Runs Above Average instead focuses on play-by-play data, taking a step back and focusing on the number of plays made compared to the average number of plays made by a player at said position. The pitcher's groundball tendencies, batter handedness, park, and base-out state all go into figuring out how many plays an average player at a position would make.

Here is an example of the Fielding Runs Above Average spectrum based upon the 2011 season-for the sake of consistency, the players featured below all play the same position (center field):

Excellent - Jacoby Ellsbury 11.6
Great - Nyjer Morgan 5.5
Average - Marlon Byrd 0.6
Poor - Roger Bernadina -5.2
Horrendous - Melky Cabrera -13.2

WARP components can be found in this article, which also describes 2015 changes to FRAA: http://www.baseballprospectus.com/article.php?articleid=27944

Fielding runs above average.

Fielding runs above average (FRAA), adjusted for league difficulty.

FRAA for catchers is augmented with framing, throwing and blocking contributions. The total of these values is called FRAA_ADJ.

FRAA_ADJ = CSAA_RUNS + EPAA_RUNS + TRAA_RUNS + SRAA_RUNS
= Framing Runs + Blocking Runs + Throwing Runs

FRAA_ADJ is then added to the "normal" FRAA components, such as fielding ground balls, to generate a total FRAA for the catcher.

Fielding Runs Above Replacement. The difference between an average player and a replacement player is determined by the number of plays that position is called on to make. That makes the value at each position variable over time. In the all-time adjustments, an average catcher is set to 39 runs above replacement per 162 games, first base to 10, second to 29, third to 22, short to 33, center field to 24, left and right to 14.

Fielding runs above replacement. A fielding statistic, where a replacement player is meant to be approximately equal to the lowest-ranking player at that position, fielding wise, in the majors. Average players at different positions have different FRAR values, which depend on the defensive value of the position; an average shortstop has more FRAR than an average left fielder.

Fielding Runs Above Replacement. The difference between an average player and a replacement player is determined by the number of plays that position is called on to make. That makes the value at each position variable over time. In the all-time adjustments, an average catcher is set to 39 runs above replacement per 162 games, first base to 10, second to 29, third to 22, short to 33, center field to 24, left and right to 14.

See FRAR, FRAR2. FRAR2 incorporates adjustments for league difficulty and normalizes defensive statistics over time.

how many pitches a catcher had a chance/need to frame

how many pitches a catcher had a chance/need to frame

how many runs RPM would assign using a generic .14 runs available per frame

how many runs RPM would assign using a generic .14 runs available per frame

runs RPM credits to the catcher, using the ball-strike context to calculated run value

runs RPM credits to the catcher, using the ball-strike context to calculated run value

A player's pitcher's Fair Run Average, relative to the league average - 100 means average, 120 is 20% better than average, etc.

Fair Run Average Plus is calculated by taking a pitcher's Fair Run Average, dividing it by the league-average, and then subtracting that number from two. The reasoning is provided by Colin Wyers in the Fair Run Average Plus introduction. In addition, park and league quality adjustments are made.

The Five-Year Attrition forecast measures a player's Attrition Rate and Drop Rate over the forthcoming five seasons. These forecasts consider only players who have completed the comparable year in question.

The Five-Year Forecast is a player's weighted mean PECOTA forecast, taken over his next five seasons.

The Five-Year Performance forecast measures a hitter's forecast EqA or a pitcher's EqERA at various percentiles (90th, 75th, 60th, 50th, 40th, 25th and 10th) over the course of the next five seasons. The percentile forecasts are indicated by solid lines, usually in BLUE, except for his median/50th percentile forecast which is indicated in RED. Also listed is the player's weighted mean forecast in that category, indicated with a dashed YELLOW line.

The Five-Year WARP forecast measures a player's projected wins above replacement. For position players, this value is subdivided into batting wins, and defensive wins.

Speed Changes - This is the average difference, in seconds, between back-to-back pitches.

Speed Changes - This is the average difference, in seconds, between back-to-back pitches.

Pitches a catcher potentially had some responsibility for the call of a ball or strike

Framing Chances include a called balls and strikes that were not out of the extreme region of the plate. All of the excluded pitches were determined to have 0 probability of being called a strike (including but not limited to pitches in the dirt or behind the batter)

Games played (pitched, fielded, officiated).

Properly speaking, a pitcher should only be credited with a game played on his batting line when he actually appears in the lineup (i.e., not when a DH hits for him.) The BP database is currently inconsistent in this respect.

Ratio of ground balls to fly balls.

Ground advancement opportunities: number of times a baserunner was involved in one of the following situations:

• Runner on first only with less than two outs, ground ball or bunt is hit to an infielder where a hit or an error is not credited
• Runner on second only with less than two outs, ground ball or bunt is hit to an infielder where a hit or an error is not credited
• Runner on third only with less than two outs, ground ball or bunt is hit to an infielder where a hit or an error is not credited

In player or team statistical context, batted balls that were classified as ground balls.

In team standings context, Games Back. How far this team is behind the team leading the division. The formula is

((Division Leader's Wins - This team's Wins) + (This team's Losses - Division Leader's Losses)) / 2

The Division Leader is the team with the highest team Wins minus team Losses. GB is traditionally expressed as a dash (-) for the division leader and a whole or half number for teams behind that team. For teams lagging the Division Leader, a win or a Division Leader Loss will reduce their GB by half a game.

GB is not recalculated for League or All MLB groupings; it always reflects a team's status relative to the leader of their division.

Percentage of batted balls that were classified as ground balls (percentage is based on the number of batted balls that were classified at all -- batted balls which do not have a known type are omitted)

Grounded into double play. Not recorded prior to 1933 in the NL, or 1939 in the AL, and not at all for the other leagues. Unfortunately, without opportunity information, I don't find it very useful for inclusion in EqA. There is also evidence, from Tom Ruane, that players who hit into more DP also tend to advance more runners with outs, enough to offset the DPs.

Grounded into Double Play

Amount of times a hitter grounded into or a pitcher induced a double play.

Games in relief

Games started by a pitcher.

Games played at the position of first base

Games played at the position of second base

Games played at the position of third base

Games played at the position of catcher

Games played at the position of center field

Games played at the position of designated hitter

Games played at the position of left field

Guillen Number, the percentage of a team's runs which come via home runs.

Named after manager Ozzie Guillen by Joe Sheehan, because Guillen's White Sox teams have owed much more of their scoring to homers than to the one-run strategies to which their success was often attributed. For historical backgrounds, see here.

Games played at the position of pitcher

Games played as a pinch hitter

Games played as a pinch runner

Games played at the position of right field

Games played at the position of shortstop

How many games the player missed due to the injury.

Number of batted balls classified as ground balls

Hits, or hits allowed.

See BABIP.

Hits allowed per 9 innings pitched.

Hit advancement opportunities: number of times a runner could have gone from first to third on a single, first to home on a double, or second to home on a single.

Hit by pitch.

Not recorded for the NL 1876-1886, the AA in 1882-83, the 1884 UA, and the 1871-75 NA, for either hitters or pitchers.

Hit By Pitch Rate -- HBP per plate appearance

Hit Rate -- hits per plate appearance

Hit List Factor: An average of a team's actual winning percentage and the three Pythagenpat winning percentages from our Adjusted Standings Report, (as well as the Depth Chart win percentage early in the season).

Used to determine a team's ranking in the Prospectus Hit List power rankings.

You can find more information on the process here.

Home runs, or home runs allowed.

Home runs allowed per 9 innings pitched.

Home Runs per Inning Pitched

Home Run Rate -- homers per plate appearance

Hits allowed per 9 innings pitched

Hits per inning pitched

Femoral-Acetabular Impingement Labroplasty is the procedure done to players such as Chase Utley, Mike Lowell, and Alex Rodriguez to repair damage in their hip. First done on skiiers, the procedure was first used in baseball players in the 2008-2009 off-season with a "hybrid" operation pioneered to bring Rodriguez back in just 60 days.

Historical Stats are the player's previous three seasons of performance as they appear in the BP book (with the addition of a player's WARP scores).

The team's ranking in the latest Prospectus Hit List article. Unlike many power rankings, the Prospectus Hit List rankings are determined objectively via the Hit List Factor, an average of a team's actual winning percentage and the three Pythagenpat winning percentages from our Adjusted Standings report. The first-order winning percentage is calculated via actual runs scored and runs allowed, the second-order winning percentage uses Equivalent Runs scored and allowed, which are calculated from run components (hits, walks, total bases, stolen bases, outs, etc.) and adjusted for park and league scoring levels, and the third-order winning percentage uses Adjusted Equivalent Runs scored and allowed, which adjust the Equivalent Runs totals for the quality of each team's opponents' pitching and defense. You can find more information on the process here.

While definitions vary, the most common ones credit a pitcher with a "Hold" when he a) enters the game with a lead, b) records at least one out, and c) leaves the game still in the lead.

Intentional walks.

Not recorded for any league prior to 1955.

Intentional base on balls rate (per plate appearance)

Inherited baserunners.

Total expected run value from inherited runners (runners who are on base when the reliever entered his games).

Number of runners who were inherited by the pitcher (they were on base when he came into the game) and scored while the pitcher was in the game.

Number of runners who were inherited by the pitcher (they were on base when he came into the game) and scored eventually. This includes runners who were on base before the pitcher entered the game and scored after the pitcher left the game.

Innings officated.

Innings completed by a pitcher

Inherited runs prevented from scoring. The expected number of inherited runners that would score in the reliever's appearances based upon league average performance, minus the actual number the reliever allowed to score.

Inherited runners who scored. A raw count of the number of runners who scored. This differs from INR, which subtracts INS from the expected number of inherited runners that would have scored given league average performance in the given situations.

Number of times catcher interference was called

Innings Pitched.

Innings pitched as a relief pitcher

Innings pitched as a starting pitcher

The amount of innings pitched as a reliever.

The amount of innings pitched as a starter.

Innings pitched per start.

Isolated Power (ISO) is a measure of a hitter's raw power, in terms of extra bases per AB. The formula is SLG-AVG, or (2B+3B*2+HR*3)/AB (the two are equivalent).

Improve Rate is the percent chance that a player's production will improve at all relative to his baseline performance.

A player who is expected to perform just the same as he has in the recent past will have an Improve Rate of 50 percent.

Inherited runs prevented from scoring. The expected number of inherited runners that would score in the reliever's appearances based upon league average performance, minus the actual number the reliever allowed to score.

A negative number means the reliever prevented fewer runs than average, while a positive number means the relieve prevented more runs than average.

Inherited Runners. The total number of runners on base when the pitcher came into the game.

The type of injury-i.e. soreness, laceration, contusion, etc.

A "quick and dirty" measure of the lost value due to injuries. The formula used is MORP divided by 180 multiplied by days expected lost.

Abbreviation for "Jaffe WARP Score." System invented by Jay Jaffe to assess a player's worthiness for enshrinement in the Hall of Fame. Equal to the average of a player's peak WARP and total career WARP. Jaffe used the system before, but the term was coined here.

The methodology is explained in full here.

The very self-consciously named Jaffe WARP Score system, which is designed to determine how a Hall of Famer or Hall of Fame candidate measures up to his enshrined peers at his position with regards to his regular season pitching, hitting, and fielding contributions. The goal of JAWS is to identify players who are above-average candidates for Hall of Fame enshrinement in these respects.

A player's JAWS score is the average of his career WARP total and his peak total [(Career WARP + Peak WARP) / 2], where Peak is a player's best seven seasons (early versions of the system used best five consecutive, but this method was abandoned starting with the 2006 BBWAA ballot). This JAWS score is then compared to a modified average of the enshrined Hall of Famers at each position, with a slight adjustment made for positional scarcity among enshrinees.

Because the WARP data undergoes minor tweaks from time to time, JAWS standards at each position need occasional re-computation. The standards for the 2012 BBWAA ballot are:

POS WARP  Peak  JAWS
C    51.7  33.9  42.6
1B   61.1  40.8  51.4
2B   64.7  43.2  53.8
3B   68.6  45.3  55.0
SS   60.6  40.3  50.7
LF   65.1  42.0  53.5
CF   72.8  46.8  58.3
RF   66.2  40.9  53.6
SP   51.1  36.0  43.5
RP   29.1  17.5  23.3

The Jeremy Giambi Effect is a name given to the correlation between playing time and quality of performance. The Jeremy Giambi Effect has important implications for understanding a player's PECOTA forecast.

Strikeouts per 9 innings pitched.

Refers to a pitcher's losses. In context of a team rather than an individual pitcher, refers to team losses.

"First order losses." Pythagenport expected losses, based on RS and RA.

"Second order losses." Pythagenport losses, based on EQR and EQRA.

"Third order losses." Pythagenport losses, based on AEQR and AEQRA.

League-Average Innings Muncher, a term coined by blogger Travis Nelson that is associated with adequate back-end rotation types.

Total expected run value of all inherited runners still on base when the inheriting pitcher is removed.

Batted balls classified as line drives

Percentage of batted balls that were classified as line drives (percentage is based on the number of batted balls that were classified at all -- batted balls which do not have a known type are omitted)

Number of times a player led off an inning, as a rate of his total PA.

Number of times the player led off an inning.

Leverage measures how important the situations a reliever has been used in are. A leverage of 1.00 is the same importance as the start of a game. Leverage values below one represent situations that are less important than the start of a game (such as mopup innings in a blowout). Leverage values above one represent situations with more importance (such as a closer protecting a one-run lead with bases loaded in the 9th inning).

Mathematically, leverage is based on the win expectancy work done by Keith Woolner in BP 2005 (read an explanation by Dan Fox here), and is defined as the change in the probability of winning the game from scoring (or allowing) one additional run in the current game situation divided by the change in probability from scoring (or allowing) one run at the start of the game.

League. 'A' or 'AL' denotes American League. 'N' or 'NL' denotes National League.

Lefty One Out GuY - a left handed reliever specializing in getting one out, often in game critical situations

Luck, as measured by the number of extra wins, and short losses the pitcher actually got, versus his expected record. LUCK = (W-E(W))+(E(L)-L)

The highest number of pitches thrown by a pitcher in one outing.

The maximum amount of Pitcher Abuse Points a pitcher has accumulated in a single start.

Maximum number of pitches in a start

Maximum Pitcher Abuse Points (PAP) in a single start

Someone who can play both middle infield positions, second and short.

A result of a play missing from the BP databases.

MLB% is the percentage of the comps who played in MLB the following season

Marginal Lineup Value, a measure of offensive production created by David Tate and further developed by Keith Woolner. MLV is an estimate of the additional number of runs a given player will contribute to a lineup that otherwise consists of average offensive performers. Additional information on MLV can be found here.

MLVr is a rate-based version of Marginal Lineup Value (MLV), a measure of offensive production created by David Tate and further developed by Keith Woolner. MLV is an estimate of the additional number of runs a given player will contribute to a lineup that otherwise consists of average offensive performers. MLVr is approximately equal to MLV per game. The league average MLVr is zero (0.000). Additional information on MLV and MLVr can be found here.

Marginal Value Above Replacement Player was as introduced in this article. It was updated in this article and this article.

It is set to MORP = $5.0*WARP3 for 2010. Subsequent years can be estimated at about 8% inflation. The benefit of our new MORP formula is that it adjusts for the facts that (1) Draft Picks are part of the cost of Free Agents, (2) Free Agents typically under-perform their projections, and (3) Deals signed before the off-season are part of the labor market.

Marginal Payroll Dollars per Marginal Win, a measure introduced by Doug Pappas which evaluates the efficiency of a club's front office by comparing its payroll and record to the performance it could expect to attain by fielding a roster of replacement-level players, all of whom are paid the major league minimum salary. The formula is:

(club payroll - (28 x major league minimum) / ((winning percentage - .300) x 162)

Recent MLB-wide MP/MW rates using end-of-year payrolls:

2007: $2,460,984

2008: $2,625,267

2009: $2,652,167

95th percentile of velocity among "hard" pitches thrown. These include 4-seam, 2-seam, and cut fastballs.

95th percentile of velocity among "hard" pitches thrown. These include 4-seam, 2-seam, and cut fastballs ("FA","SI","FC" from Pitch Info, as found on player cards and at Brooks Baseball site).

Player's name.

Normalized ERA

The number of additional double plays generated versus an average player with the same number of opportunities. Negative NET DP indicates that fewer double plays than average were produced.

Total number of pitches thrown.

Normalized Runs Allowed. "Normalized runs" have the same win value, against a league average of 4.5 and a pythagorean exponent of 2, as the player's actual runs allowed did when measured against his league average.

Non-Strikeout Out Rate -- batting outs (other than by strikeout, i.e. outs on balls in play) per plate appearance.

Other advancement opportunities: number of opportunities to advance on wild pitches, passed balls, and balks.

Others Batted In -- runs batted in, except for the batter driving himself in via a home run. Equal to RBI-HR

Others Batted In Percentage. Percentage of all runners on base batted in.

On-base percentage. (H + BB + HBP) divided by (AB + BB + HBP + SF). For pitchers, OBP is on base percentage allowed.

The final score, OFP, is an abbreviation of Overall Future Potential. This is a scout's single score on a player. It is not an average of his individual scores.

The final score, OFP, is an abbreviation of Overall Future Potential. This is a scout's single score on a player. It is not an average of his individual scores, as those scores (plus other factors, such as position) need to be weighed differently on a case-by-case basis. The OFP scale works just like the individual tool scale. A 50 score indicates that the scout thinks the players will be an average major league regular. A score in the mid-60s or higher indicates that the player projects to be a star, while a score under 40 usually means a NP or "No Prospect." (from: The Scouting Scale section in this article from Kevin Goldstein)

Total baserunning opportunities: GA_OPPS + SB_OPPS + AA_OPPS + HA_OPPS + OA_OPPS.

Opponent's Quality, Batting Average -- the aggregate batting average of all batters faced (by a pitcher), or allowed by all pitchers faced (for a batter)

Opponent's Quality, On-Base Percentage -- the aggregate onbase percentage of all batters faced (by a pitcher), or allowed by all pitchers faced (for a batter)

Opponent's Quality, On-Base plus Slugging Average -- the aggregate OPS of all batters faced (by a pitcher), or allowed by all pitchers faced (for a batter)

Opponent's Quality, Slugging Average -- the aggregate slugging average of all batters faced (by a pitcher), or allowed by all pitchers faced (for a batter)

Opponent's Quality, True Average -- the aggregate True Average of all batters faced (by a pitcher), or allowed by all pitchers faced (for a batter).

On Base Percentage + Slugging Percentage

Out Rate. Batting outs per plate appearance.

Known outs made by the player or induced by a pitcher, defined by AB-H+CS+SH+SF.

Equivalent Outs.

A player's offensive wins above replacement, as listed on his PECOTA card. Analagous to BRAR.

Offensive Winning Percentage. A Bill James stat, usually derived from runs created. In EqA terms, it could be calculated as (EQA/refEQA)^5, where refEQA is some reference EQA, such as league average (always .260) or the position-averaged EQA.

Out-of-zone contact rate: percentage of swings on pitches out of the zone on which contact is made.

This is calculated from PITCHf/x data and uses the rule-book strike zone.

Out-of-zone Swing Rate: Percentage of pitches out of the zone swung at.

This is calculated from PITCHf/x data and the rule-book strike zone.

'Out of Baseball' is the tag assigned to a player's five-year forecast when his Drop Rate in that season exceeds 66.7%. That is, we do not list a player's forecast line when it is substantially more likely than not that he will not be playing professional baseball.

Plate appearances; AB + BB + HBP + SH + SF.

The percentage of the team's total plate appearances that this player had.

Park-Adjusted Defensive Efficiency: Measures the percentage of balls in play that a team's defense converts into outs, with a park adjustment factor.

Based off of Bill James' Defensive Efficiency idea, PADE calculates how well a team performed on defense, while adjusting for their park environments. Certain parks make it easier for the defense to turn a ball in play into an out and this adjusts for that fact.

Introduced by James Click here and updated by Click here.

Here is an example of the Park-Adjusted Defensive Efficiency spectrum based on the 2011 season:

Excellent - Tampa Bay 4.30
Great - Los Angeles of Anaheim 1.47
Average - Atlanta -0.02
Poor - Chicago (A) -1.41
Horrendous - Minnesota -2.41

Pitcher Abuse Points. When used in the Pitcher Abuse Point report, PAP refers to PAP^3, which assigns 0 PAP to a start in which the pitcher throws 100 or fewer pitches and (PC-100)^3 PAP for all other starts.

Plate appearances at the position of first base

Plate appearances at the position of second base

Plate appearances at the position of third base

Plate appearances at the position of catcher

Plate appearances at the position of center field

Plate appearances as a designated hitter

Plate appearances at the position of left field

Plate appearances at the position of pitcher

Plate appearances as a pinch hitter

Plate appearances as a pinch runner

Plate appearances at the position of right field

Plate appearances with runners on base

Plate appearances at the position of shortstop

Passed balls; not available for the NA.

Pitcher Base-Run Average. The PBRA is a newer, slightly more accurate replacement for the PERA. As the name indicates, it is a modification of the BaseRuns concept of run estimators.

Set B = 1.36 (H-HR) + BB + HBP - .06 K

This is your baserunner term.

PBR = HR + X * B * (B+HR) / TBF ,

where X is a constant set for the league, typically around .67.

PBRA is simply PBR/IP *9.

You can also use expected hits allowed instead of actual hits allowed; I call that the PBRA2, and also adjust the innings for the difference between actual and expected hits. If you are working with translated statistics, then you can use the per nine inning stats, with X=.695 and TBF=27 + H/9 + BB/9. You may see small differences between this calculation and what is displayed; HBP, which are included in the DTs even though they are not displayed, are the biggest reason for that.

the difference between actual and predicted passed balls and wild pitches allowed by the catcher

the difference between actual and predicted passed balls and wild pitches allowed by the catcher

PEAK refers to a series of metrics designed to evaluate a player's value in some statistic - most often WARP or non-negative WARP (used by UPSIDE calculations) - over a series of consecutive seasons.

PEAK refers to a series of metrics designed to evaluate a player's value in some statistic - most often WARP or non-negative WARP (used by UPSIDE calculations) - over a series of consecutive seasons. It has had two variations. The one currently in use for UPSIDE on the player cards is the five-year variant referenced by Nate Silver:

The version of Upside that we’re using here is the peak-adjusted variant, which measures a player’s most valuable five-year window up through and including his age 28 season (or simply his next five years of performance if he’s already age 25 or older). -- Nate Silver, 2007

Also used in some writings simply uses the next six seasons of a player's career.

In both cases, seasons which have yet to be played are projected using PECOTA instead of ignored, so young players will have the full complement of five (or six) seasons of data. See also: UPSIDE.

Stands for Player Empirical Comparison and Optimization Test Algorithm. PECOTA is BP's proprietary system that projects player performance based on comparison with historical player-seasons. There are three elements to PECOTA:

1) Major-league equivalencies, to allow us to use minor-league stats to project how a player will perform in the majors;
2) Baseline forecasts, which use weighted averages and regression to the mean to produce an estimate of a player's true talent level;
3) A career-path adjustment, which incorporates information about how comparable players' stats changed over time.

Check out the PECOTA section of the glossary for more on the system's intricacies.

Payroll Efficiency Rating, measure developed by Shawn Hoffman expressing the ratio of a team's estimated marginal revenue (derived from third-order win totals and market size factors) to its expected marginal revenue (derived from payroll). Draft pick value is also factored in to account for the increased value of a high first-round pick. The concept behind PER was introduced here though the name came later. PER' is a variant of this which substitutes actual win totals for third-order win totals in the estimated marginal revenue calculation.

PERA is a pitcher's ERA as estimated from his peripheral statistics (EqH9, EqHR9, EqBB9, EqK9). Because it is not sensitive to the timing of batting events, PERA is less subject to luck than ERA, and is a better predictor of ERA going-forward than ERA itself. Like the rest of a pitcher's equivalent stats, his PERA is calibrated to an ideal league with an average PERA of 4.50.

A component of the Pitch F/X dataset, PFX refers to the horizontal movement, in inches, of a pitch thrown. On an individual basis, righthanded pitchers will have negative horizontal movement on a fastball with lefties posting positive numbers. In larger studies, this data is normalized to avoid any type of skewed results.

A component of the Pitch F/X dataset, PFZ is categorized as the vertical movement, in inches, of a pitch thrown. This is often referred to as the rise or sink on a pitch. The greater the number, the more rise. Sinkerballers and those with two-seam fastballs strive for very low PFZ marks.

Number of times picked off

Player Injury Projection Probabilities. This is the name for the rating system that underlies the Team Health Reports. The name was submitted by reader braden23 in honor of Wally Pipp, who may have the most famous injury in all of baseball history.

This is the number of sequential pitchers in the sample for the given selection.

This is the number of sequential pitchers in the sample for the given selection.

1st Pitch Type: This is the selected pitches for drilling down on a specific sequence.

This is the selected pitches for drilling down on a specific sequence.

2nd Pitch Type: This is the selected pitches for drilling down on a specific sequence.

This is the selected pitches for drilling down on a specific sequence.

A pitcher's park-adjusted RA, expressed on a scale like ERA or RA. RA+ -- Park and league normalized Run Average. Similar to ERA+ found in Total Baseball, but based on RA rather than ERA.

Positional MLV. Runs contributed by a batter beyond what an average player at the same position would produce in a team of otherwise league-average hitters.

Positional MLV rate. Runs/game contributed by a batter beyond what an average player at the same position would hit in a team of otherwise league-average hitters. Like MLVr, it is a rate stat. The comparable season total is PMLV.

Putouts.

Number of batted balls that were classified as popups

Percentage of batted balls that were classified as popups (percentage is based on the number of batted balls that were classified at all -- batted balls which do not have a known type are omitted)

Primary position played (position where the most PA were accumulated). Position numbers: 1=pitcher, 2=catcher, 3=first base, 4=second base, 5=third base, 6=shortstop, 7=left field, 8=center field, 9=right field, 10=designated hitter, 11=pinch hitter, 12=pinch runner. The label "0" can apply to a pinch-hitter (or -runner) when the team bats around, coming to that lineup spot for the second time in an inning.

The defensive value of the position a player plays, in total runs relative to the average player.

Sacrifice bunts (SAC or SH) by position players.

Sacrifice bunts (SAC or SH) by position players (non-pitchers).

Power Percentage, a statistic created by Julien Headley, is described here. POW describes extra-base power on contact, in terms similar to Isolated Power. The formulation used in the Minor League Statistics and Translations page is POW=(2B+(2*3B)+(3*HR))/(AB-SO).

The number of team pickoffs accumulated by runners on first base.

The number of team pickoffs accumulated by runners on second base.

The number of team pickoffs accumulated by runners on third base.

Pitching Park Factor.

PPF is centered around 100, with numbers above and below representing percentage that run-scoring was increased by the mix of parks the pitcher pitched in. For instance, 110 represents 10% above average and 96 represents 4% below average.

Times a pinch runner was used.

Times a pinch runner was used - usually associated with a manager.

Pitcher-only runs above average. The difference between this and RAA is that RAA is really a total defense statistic, and PRAA tries to isolate the pitching component from the fielding portion. It relies on the pitching/fielding breakdown being run for the team, league, and individual. The individual pitching + defense total is compared to a league average pitcher + team average defense, and the difference is win-adjusted.

Pitcher runs above average, adjusted for league difficulty.

Pitcher-only runs above replacement. Similar to PRAA, except that the comparison is made to a replacement level player instead of average. The nominal RA for a replacement pitcher is 6.11 (the same ratio, compared to a 4.50 average, as a .230 EQA is to .260). This assumes that there is a 50/50 split between pitching and fielding. If the pitch/field split is less than that, as it was in the 1800s, the replacement ERA is reduced.

Pitcher-only runs above replacement. Similar to PRAA, except that the comparison is made to a replacement level player instead of average. The nominal RA for a replacement pitcher is 6.11 (the same ratio, compared to a 4.50 average, as a .230 EQA is to .260). This assumes that there is a 50/50 split between pitching and fielding. If the pitch/field split is less than that, as it was in the 1800s, the replacement ERA is reduced.

Pitching runs above replacement (PRAR), adjusted for league difficulty.

the number of passed balls and wild pitches predicted by RPM

the number of passed balls and wild pitches predicted by RPM

the number of strikes the catcher is expected to have received according to RPM

the number of strikes the catcher is expected to have received according to RPM

Value over Replacement Player (VORP) as a pitcher.

Wins Above Replacement Player (WARP) as a pitcher.

An adjustment made to account for the fact that some parks are easier to hit in than average, giving an advantage (in raw statistical terms) to hitters who play for that team. Park factors are always made relative to a league average of 1.00. The park adjustments in the BP are made only on the park factor for runs, averaged over five years; they can be found here. The first column is a one-year park factor, the second column is the five-year average centered on that year (assuming the team did not change or massively renovate their park).

Winning percentage of a team. Computed as team Wins divided by Games played, and traditionally expressed in three digit decimal form.

1st Order Winning Percentage uses Pythagenpat method based on actual runs scored and runs allowed to determine how often a team "should have" won based on their run differential.

Clay Davenport introduces higher-order winning percentage in this article.

2nd Order Winning Percentage substitutes projected runs scored for actual runs scored. This calculates, based on a team's underlying stats, how many runs they "should have" scored and uses that in the Pythagenpat method.

Uses Equivalent Runs scored and allowed, which are calculated from run components (hits, walks, total bases, stolen bases, outs, etc.) and adjusted for park and league scoring levels.

Clay Davenport introduces higher-order winning percentage in this article.

3rd Order Winning Percentage: A team's projected winning percentage, based on underlying statistics and adjusted for quality of opponents.

Uses Adjusted Equivalent Runs scored and allowed, which adjust the Equivalent Runs totals for the quality of each team's opponents' pitching and defense.

Clay Davenport introduces higher-order winning percentage in this article.

95th percentile of velocity among "hard" pitches thrown. These include 4-seam, 2-seam, and cut fastballs.

95th percentile of velocity among "hard" pitches thrown. These include 4-seam, 2-seam, and cut fastballs ("FA","SI","FC" from Pitch Info, as found on player cards and at Brooks Baseball site).

The number of additional runs charged to the starting pitcher that his bullpen allowed to score after he left the game, compared to an average bullpen. Negative Pen Support means the bullpen prevented more runs from scoring than an average pen (i.e. the pitcher's ERA looks better than it should because of good bullpen support).

The Percentile Forecast is a representation of the player's expected performance in the upcoming season at various levels of probability. For example, if a pitcher's 75th percentile ERA forecast is 3.50, this indicates that he has a 75 percent chance to post an ERA of 3.50 or higher, and a 25 percent chance to post an ERA lower than 3.50. Higher percentiles indicate more favorable outcomes.

The Percentile Forecast is calibrated off two key statistics: TAv for hitters, and ERA for pitchers (although the ERA is a component ERA, and thus will not reflect the variance of sequencing in a player's performance).

PECOTA runs a series of regressions within the set of comparable data in order to estimate how changes in peripheral statistics are related to changes in equivalent runs. For example, if it first estimates that Carl Crawford will produce a .290 TAv next year, it then tries to determine what home run total, walk total, and so on are most likely to be associated with a .290 TAv season.

PECOTA then iterates this result to ensure that the peripheral statistics 'add up' to the right calibrating statistic (TAv or ERA). It is important to note that the Percentile Forecast is designed to work around the calibrating statistic only.

A player's forecast is adjusted to the park and league context associated with the team listed at the top of the forecast page. Team dependant stats like Wins, RBIs, and BABIP account for the projected performance level of a player's teammates

PECOTA forecasts playing time (plate appearances) in addition to a player's rate statistics. These forecasts are based on a player's previous record of performance, and the comparable player data, and do not incorporate any additional information about managerial decisions.

On the custom statistic reports, the Pitcher column is a unique identification number for the respective pitcher.

This stat details the additional called strikes outside the reference zone that are credited to the pitcher after accounting for catcher, umpire, pitch type, etc. This stat is calculated on all called pitches (i.e., balls not in play). Pitcher CSAA is a proxy for command, or the pitcher's ability to locate the ball precisely. Both "expected" / mean values and SDs are provided.

This stat details the additional called strikes outside the reference zone that are credited to the pitcher after accounting for catcher, umpire, pitch type, etc. This stat is calculated on all called pitches (i.e., balls not in play). Pitcher CSAA is a proxy for command, or the pitcher's ability to locate the ball precisely. Base "CSAA" values are the "expected" or "mean" values for each player. We're now also pleased to provide, for seasons 2008 to the present, the standard deviations (SD) for both CSAA and CSAA / Framing Runs. SDs allow you to calculate uncertainty intervals to say how certain we are that the true measurement of the player falls within the defined interval.

Number of pitches seen (batter) or thrown (pitcher)

Described more completely in the 2002 Prospectus, the breakdown is a sequence of calculations designed to separate the pitching and fielding components of defense from each other. Certain events (walks, strikeouts, home runs) are considered to be entirely the responsibility of the pitcher. Errors and double plays are assumed to be entirely the domain of the fielders. Other hits and outs are assumed to be 75% fielding, 25% pitching.

The stats versus pitchers or hitters of each side - left or right.

Complete statistical data is available for:

• Batters vs left-handed pitchers (LHP)
• Batters vs right-handed pitchers (RHP)
• Pitchers vs left-handed batters (LH)
• Pitchers vs right-handed batters (RH)

For Hitters:

The Player Profile is a chart that evaluates a given hitter's primary production metrics (batting average, isolated power, unintentional walk rate, strikeout rate, and speed score) as a percentile compared to all major league hitters. For example, a player with an isolated power rating of 75% is superior in this category to three-quarters of all major leaguers. The player profile is based on the player's three previous seasons of performance, rather than his projection.

For Pitchers:

The Player Profile is a chart that evaluates a pitcher's performance in five categories: strikeout rate, walk rate, opponents' isolated power (e.g. home run rate), hit rate on balls in play, and groundball-to-flyball ratio. The rates are presented as a percentile compared to all major league pitchers; for example, a player with a strikeout rating of 75% is superior in this category to three-quarters of all major leaguers. The player profile is based on the player's three previous seasons of performance, rather than his projection.

The Playoff Odds Report displays the latest postseason chances generated through daily simulation of the rest of the season.

Within the Playoff Odds Report users can find and sort teams by their expected winning percentage (with a breakdown of expected wins and losses), the likelihood of them making the postseason (with a breakdown of division odds versus Wild Card odds), and how their odds have shifted over the past day or week. For more on the Playoff Odds Report, check out that portion of the glossary.

The percentage of times a team makes the playoffs - either through winning their division or their league's Wild Card - in the simulated seasons.

The percentage of times a team makes the playoffs - either through winning their division or their league's Wild Card - in the simulated seasons.

For PECOTA, a player's Position is a consideration in identifying his comparables, as well as in calculating his VORP. The player's primary position as used by PECOTA is listed at the top of his forecast page; however, secondary and tertiary positions are also considered based on the relative amount of appearances that a player receives there. The position determination is made primarily based on the position(s) that a player appeared in his most recent season, with lesser consideration given to the position(s) he appeared other recent previous seasons. Both major league and minor league defensive appearances are considered in the determination of a player's position, but major league appearances are weighted more heavily. PECOTA considers LF, CF and RF to be separate positions.

When listed numerically on our statistical reports, positions are: 1, pitcher; 2, catcher; 3, first base; 4, second base; 5, third base; 6, shortstop; 7, left field; 8, center field; 9, right field; 10, designated hitter; 11, pinch hitter; 12, pinch runner.

Break Differential - This stat tells us how much each spin-induced movement is generated on each pitch between the tunnel point and home plate. Think of this like PITCHf/x pitch movement, except that it is only tracking the time between the Tunnel Point and home plate.

Break Differential - This stat tells us how much each spin-induced movement is generated on each pitch between the tunnel point and home plate. Think of this like PITCHf/x pitch movement, except that it is only tracking the time between the Tunnel Point and home plate.

Pythagorean Over/Under. Compute the team's Pythagenpat wins using the Smith/Patriot methodology as indicated in the Pythagenpat glossary entry. Subtract this number from the team's actual wins.

A positive result indicates that a team is outplaying, or "over", its expected record; a negative result indicates a team is lagging, or "under", its expected record.

Pyth O/U is not a good indicator of team quality; a mediocre team can easily have a better Pyth O/U than a great team. Rather, in the abstract a team with a significantly negative Pyth O/U could warrant consideration as a slightly better future bet than their actual record would indicate, and the reverse is true for a team with a significantly positive O/U.

A modified form of Bill James' Pythagorean formula. Instead of using a fixed exponent (2, 1.83), the Pythagenpat formula, developed by Smyth/Patriot, derives the exponent from the run environment - the more runs per game, the higher the exponent. It also improves upon a similar formula, the Pythagenport formula, developed by Clay Davenport and previously used in our Adjusted Standings calculations.

For Pythagenpat, the exponent X = ((rs + ra)/g)^.285. Although there is some wiggle room for disagreement in the exponent, that equation is simpler, more elegant, and gets the better answer over a wider range of runs scored than Pythagenport, including the mandatory value of 1 at 1 rpg. See here for more.

A modified form of Bill James' Pythagorean formula previously used in our Adjusted Standings calculations, since replaced by Pythagenpat.

Pythagenport was the first such formula to use the team's run environment to modify what in the original formula had been a fixed exponent (2 or 1.83), deriving the exponent as X = .45 + 1.5 * log10 ((rs + ra)/g). The winning percentage is then calculated as (rs^x)/(rs^x + ra^x). The formula has been tested for run environments between 4 and 40 runs per game, but breaks down below 4 rpg. The original article is here.

QuikERA (QERA) estimates what a pitcher's ERA should be based solely on his strikeout rate, walk rate, and GB/FB ratio.

These three components--K rate, BB rate, GB/FB--stabilize very quickly, and they have the strongest predictive relationship with a pitcher's ERA going forward. What's more, they are not very dependent on park effects, allowing us to make reasonable comparisons of pitchers across different teams.

Formula:
QERA(unscaled) =(2.69+K%*(-3.4)+BB%*3.88+GB%*(-0.66))^2

Then, QERA is scaled to league average.
QERA(scaled) = QERA(unscaled) / League ERA * League QERA

Note that everything ends up expressed in terms of percentages: strikeouts per opponent plate appearance, walks per opponent plate appearance, and groundballs as a percentage of all balls hit into play. If, for example, Andy Pettitte has a 19.6% K rate, a 7.9% BB rate, and a 62.7% GB rate, he would have a QERA of 3.68. Note further that QERA is exponential, which is appropriate since run scoring is not linear.

Learn more in this article by Nate Silver.

Quality Start: A start where a pitcher completed at least six innings and gave up no more than three runs.

Runs scored (for hitters) or allowed (pitchers).

Runner on first. In the RBI opportunity report, refers to the number of times a batter came to the plate with a runner at first base.

Percentage of runners on first base batted in

Runners on first base batted in

Runner on second. In the RBI opportunity report, refers to the number of times the batter came to the plate with a runner at second base.

Percentage of runners on second base batted in

Runners on second base batted in

Runner on third. In the RBI opportunity report, refers to the number of times the batter came to the plate with a runner at third base.

Percentage of runners on third base batted in

Runners on third base batted in

Actual team runs allowed. Can also stand for Run Average--runs allowed, earned or otherwise, divided by innings pitched, times 9.

Park and league normalized Run Average. Similar to ERA+ found in Total Baseball, but based on RA rather than ERA.

Runs Allowed per Game.

For Pitchers:

Runs above average. At its simplest, this would be the league runs per inning, times individual innings, minus individual runs allowed. However, we have gone one step beyond that, because being 50 runs above average in 1930, in the Baker Bowl, doesn't have the same win impact as being +50 in the 1968 Astrodome. The league runs per inning need to be adjusted for park and team hitting (and difficulty, for the alltime RAA), and then you can multiply by individual innings and subtract individual runs. Finally, that quantity needs to be win-adjusted. See win-adjustment.

For Fielders:

Runs above average at this position, similar to Palmer's Fielding Runs as far as interpretation is concerned.

Rank by Equivalent Average

Rank by equivalent strikeouts per 9 innings

Rank by Fielding Runs Above Replacement

Rank by Wins Expected Above Replacement Player

Runs Above Position: The number of Equivalent Runs this player produced, above what an average player at the same postion would have produced in the same number of outs.

Runs Above Replacement. For a fielder, it is simply Runs Above Replacement for the position, where a replacement-level fielder is determined to be about 20 runs below average for the position; the number varies slightly depending on the number of balls in play.

Runs Above Replacement, Position-adjusted. A statistic that compares a hitter's Equivalent Run total to that of a replacement-level player who makes the same number of outs and plays the same position. A "replacement level" player is one who has 22.1 fewer EqR per 486 outs than the average for that position. For the overall league average (.260), that corresponds to a .230 EqA and a .351 winning percentage.

Essentially, this is the Equivalent Average analog of VORP.

Runs Batted In.

Number of runs a batter has driven in per runner on base during a batter's plate appearances. Defined as total baserunners/RBI (NB: Runners on base are other than the batter himself--RBI's resulting from a batter driving himself in on home runs are removed).

RBI + R - HR. Used in fantasy baseball to approximate runs created in a simple fashion.

RBI Rate -- RBI per plate appearance

Win-Loss record for a particular team and run differential

Relief Percentage -- positive relief decisions (saves and holds) divided by total relief decisions (saves, holds, blown saves)

The number of runs an average player would have produced relative to replacement level.

Raw equivalent average, the first step towards building the EqA. In its fullest form, REQA = (H + TB + 1.5*(BB + HBP + SB) + SH + SF) divided by (AB + BB + HBP + SH + SF + CS + SB). REQA gets converted into unadjusted equivalent runs, UEQR.

Runners On Base: the number of runners on base during a batter's plate appearances.

Reached On Error: when a batter reaches base as a direct result of a fielding error.

Percentage of plate appearances that result in the batter reaching base on an error.

Reached On Error Rate -- reaching on error per plate appearance.

This indicates whether or not a player was a rookie during that season. To be a rookie, a player must have fewer than 130 at-bats and 50 innings pitched.

MLB will exclude players who have spent at least 45 days on a 25-man roster from eligibility for rookie of the year. Due to lack of service time data historically we do not exclude those players, so the rookie flag may not correspond exactly with award eligibility.

Runs Prevented. The extra number of runs an average pitcher would have allowed in the same number of innings pitched (adjusted for park and league). RP greater than zero indicates that the pitcher allowed fewer runs than an average pitcher (i.e. he's better than average). Negative RP indicates the pitcher allowed more runs than an average pitcher (i.e. he's worse than average).

A player's runs per plate appearance, relative to the league average - 100 means average, 120 is 20% better than average, etc.

RPA+ is computed as: RPA/lgRPA Where lgRPA is the league runs per plate appearance, adjusted to match a player's run environment (adjusted for park, in other words). The scale of RPA+ should correspond with that of OPS+ and similar metrics; it will produce the same rank order as True Average, however. Read more here

Runs Per Inning. RPI is the average number of runs scored per inning by a given team or lineup, used to calculate Win Expectancy. RPI is a measure of the strength of a team's offense (or conversely, the strength of the opposing team's pitching staff).

Replacement level MLV rate. Runs/game contributed by a batter beyond what a replacement level player at the same position would hit in a team of otherwise league-average hitters. The comparable season total is RPMLV. It differs from VORPr and VORP only in that it is solely based on batting performance whereas VORP includes basestealing.

Actual runs scored by a team.

Runs Scored per Game.

Denotes position of runners on base. For example, 103 denotes runners on first and third

Runs scored Rate -- Runs scored (typically by a player) per plate appearance

Runs charged to a pitcher before he is removed from the game (i.e. excluding runners on base when he exited who may have been allowed to score by a subsequent pitcher)

A way to look at the fielder's rate of production, equal to 100 plus the number of runs above or below average this fielder is per 100 games. A player with a rate of 110 is 10 runs above average per 100 games, a player with an 87 is 13 runs below average per 100 games, etc.

See Rate. Rate2 incorporates adjustments for league difficulty and normalizes defensive statistics over time.

The first step in putting together equivalent average.

In its fullest form,

RawEQA = (H+TB+1.5*(BB+HBP+SB)+SH+SF-IBB/2) / (PA+SB+CS),

where PA=AB+BB+HBP+SH+SF. Feel free to drop any variable that isn't readily available.

Whether the injury suffered is reoccurring.

Release:Tunnel Ratio - This stat shows us the ratio of a pitcher's release differential to their tunnel differential. Pitchers with smaller Release:Tunnel Ratios have smaller differentiation between pitches through the tunnel point, making it more difficult for opposing hitters to distinguish them in theory.

Release:Tunnel Ratio - This stat shows us the ratio of a pitcher's release differential to their tunnel differential. Pitchers with smaller Release:Tunnel Ratios have smaller differentiation between pitches through the tunnel point, making it more difficult for opposing hitters to distinguish them in theory.

In Team Audit or Playoff Odds Report context, the rank of a team in the grouping and sort currently active.

For instance, the default view of Team Audit is sorted by GB ascending and grouped by division. In this view, the division leaders will all rank 1, second place teams will rank 2, etc. Any teams that have the same values on the sort column will have the same Rnk.

To quickly find a team's rank in any stat, sort by that stat and refer to this column. For example, if you wanted to determine where the Padres ranked in RS/G in all of MLB, sort by the RS/G header, set your grouping to MLB, and refer to this column.

How many runs are likely to score in a certain base-out situation.

The number of runs expected to score from a particular event, based on historical data.

Stolen bases. Not recorded for any league between 1876 and 1885. On the catcher's fielding charts, not available prior to 1978.

Percentage of stolen base attempts that are successful.

Net Stolen Bases, or SB - CS.

Stolen base opportunities: SB + CS + Pickoffs.

The number of team stolen bases accumulated by runners on first base.

The number of team stolen bases accumulated by runners on second base.

The number of team stolen bases accumulated by runners on third base.

Sacrifice flies. The statistical category of "sacrifice flies" did not exist prior to 1954; the concept had been around, on and off, since 1908, but had been always been part of the "SH" category. See SH.

Simple Fielding Runs -- The runs above average contributed by a defender. SFR is a defensive metric currently in a "beta" form based on Retrosheet-style play by play data. SFR for infielders is calculated differently than that for outfielders and for outfielders the metric is park-adjusted.

Sacrifice hits. Not recorded prior to 1894. From 1894-1907, they were essentially the same as the modern rule - a bunt which advanced a baserunner. From 1908-25, they included what we would now call a sacrifice fly (sacrifices increase 25% between 1907 and 1908 as a result). From 1926-30, they included any fly ball on which a runner advanced, not just ones where the runner scored (another 25% increase in 1926). From 1931-38, sacrifice flies were eliminated completely (causing a 45% drop in sacrifices, and a 4-point decline in batting averages); that brought us back to the modern definition of sacrifice hit. In 1939 they re-introduced the run-scoring sac fly (returning to the 1908-25 rules), but eliminated it again in 1940. When sacrifice flies appeared again in 1954, they had their own category, so the rule for what we would call a sacrifice hit has not changed since 1940.

Shutouts.

Sacrifice Hit Rate -- Sacrifices per plate appearance

Skill-Interactive Earned Run Average estimates ERA through walk rate, strikeout rate and ground ball rate, eliminating the effects of park, defense and luck. It adds little value and has been retired from the Baseball Prospectus statistical offerings as of 2011. See Lost in the SIERA Madre for more explanation.

SIERA accounts for how run prevention improves as ground ball rate increases and declines as more whiffs are accrued, while grounders are of more materiality for those who allow a surplus of runners. The formula for SIERA is:

SIERA = 6.145 - 16.986*(SO/PA) + 11.434*(BB/PA) - 1.858*((GB-FB-PU)/PA) + 7.653*((SO/PA)^2) +/- 6.664*(((GB-FB-PU)/PA)^2) + 10.130*(SO/PA)*((GB-FB-PU)/PA) - 5.195*(BB/PA)*((GB-FB-PU)/PA)

where the +/- term is a negative sign when (GB-FB-PU)/PA is positive and vice versa.

This was explained in more detail in the following series: part one, part two, part three, part four, and part five.

Situations where a Double Play was possible -- a plate appearance with a runner on first base and less than two outs

Slugging percentage (hitters) or slugging percentage allowed (pitchers). Total bases divided by at-bats.

The Slugging Percentage of Balls Put in Play.

Similar to Batting Average on Balls in Play, SLGBIP gives an impression of the damage done by the balls in play. As seen here.

Support-Neutral Losses. the pitcher's expected number of losses assuming he had league-average support.

Support-Neutral Lineup-adjusted Value Added - like SNVA, but also adjusted for the MLVr of each batter the pitcher faced.

Support-Neutral Lineup-adjusted Value Added (SNVA adjusted for the MLVr of batters faced) per game pitched.

like SNLVA, but comparing to replacement level, rather than average. Replacement level is now being computed the same way in SNVA and in VORP (using the formulas from Keith Woolner's BP 2002 article).

Rate of Support-Neutral Lineup-adjusted Value Added above replacement level

Rate of Support-Neutral Lineup-adjusted Value Added

SNW / (SNW+SNL)

Support-Neutral Value Added - wins above average added by the pitcher's performance.

Support-Neutral Value Added (wins above average added by the pitcher's performance) per game pitched.

like SNVA, but comparing to replacement level, rather than average. Replacement level is now being computed the same way in SNVA and in VORP (using the formulas from Keith Woolner's BP 2002 article).

Rate of Support-Neutral Value Added

Support-Neutral Wins. the pitcher's expected number of wins assuming he had league-average support.

Support-Neutral Wins Above Replacement-level. the number of SNWs a pitcher has above what a .425 pitcher would get in the same number of (Support-Neutral) decisions.

Support-Neutral Winning Percentage

A pitcher's calculated winning percentage given his pitching performances, assuming he had a league average offense and bullpen behind him.

Michael Wolverton gives an explanation of support-neutral stats here.

Formula:

Read about the underlying mathematical method in this article.

Strikeouts. For pitchers, batters struck out, for batters, times struck out.

Percentage of plate appearances that result in a strikeout.

Strikeout to walk ratio: strikeouts divided by walks.

Strikeouts per 9 innings pitched.

Strikeouts per inning pitched

Strikeout Rate -- Strikeouts per plate appearance

Abbreviation for Speed Score as used in PECOTA cards.

SRAA - Swipe Rate Above Average - is the official name for Bases Stolen Above Average. Please click here for details: Swipe Rate Above Average

Type the definition of the term here, or leave the text as it is if you don't want to add a new term.

Swipe Rate, as its name implies, judges each participant in a base-stealing attempt for his likely effect upon its success. Using a generalized linear mixed model, we simultaneously weight all participants involved in attempted steals against each other, and then determine the likelihood of the base ending up as stolen, as compared to the involvement of a league-average pitcher, catcher, or lead runner, respectively.

(from http://bbp.cx/a/26195)

Stated another way, Swipe Rate allows us to evaluate how good Yadier Molina’s arm is while controlling for the inherent ability of his pitchers to hold runners and the quality of the runners he is facing on base. Likewise, we evaluate the ability of individual pitchers to hold runners while controlling for the possibility that they may be throwing to a catcher with a subpar arm. And for baserunners in particular, we now have something much more accurate to evaluate their base-stealing ability than base-stealing percentage.

Remember that base-stealing percentage, by itself, is not very useful: using straight percentages, an elite base-stealer who swipes 90 percent of his attempts and tries to steal 40 times a year ranks lower than a catcher who had one lucky steal all year (and therefore has a 100 percent base-stealing percentage). In the same way that Controlled Strikes Above Average (CSAA) controls for the effect of other factors on catcher framing, Swipe Rate Above Average regresses baserunners’ steal-success rates against both themselves and others to provide a more accurate assessment of each participant’s effect on the likelihood of a stolen base.

The factors considered by the Swipe Rate are:

• The inning in which the runner was on base;
• The stadium where the game takes place;
• The underlying quality of the pitcher, as measured by Jonathan Judge’s cFIP statistic;
• The pitcher and catcher involved;
• The lead runner involved.

Because the statistic rates pitchers above or below average in preventing stolen bases, average is zero, and pitchers generate either positive (bad) or negative (good) numbers. In 2014, here were the pitchers who were hardest to steal a base on:

A comprehensive Scoresheet valuation metric designed by Ben Murphy, as explained in this article.

(or SS/Sim) Runs above Replacement for Scoresheet Baseball (SS). This should also be helpful for other sim leagues. This statistic accounts for:

Stuff. A statistic developed by Clay Davenport that measures a pitcher's likelihood of success in the majors by analyzing his component rates.

Number of streaks of a particular length