Overview of Website
The basic calculation of Player won-lost records is described here. I made fairly significant modifications to some aspects of Player won-lost records in January and July of 2019. These are discussed here. Player won-lost records are compared to WAR (as calculated by Baseball-Reference and Fangraphs) in an article here.Headers and Links
Player Stat Tables
Player won-lost records are arrayed by season. For seasons in which a player played for more than one team, the default shows the player's season totals. Clicking the "+" sign next to the season will show player totals by team for the season. The season and team names link to League and Team pages for the relevant season, respectively.
Following season totals, career totals are shown on three lines. The first shows career regular-season totals. The second shows career postseason totals. Clicking the "Postseason (career)" link will open the player's postseason page. This page is described later in this document. The final row of the first two player tables, then, show combined career totals, regular season and postseason.
The headings to this table - Batting, Baserunning, Pitching, and Fielding - link to pages which decompose player performance within each factor by component (and fielding position). These tables are described later in this document.
Inter-Game compares the relative importance of situations within the same game. Inter-Game context is identical to the concept of Leverage.The final three columns of this table present what I call win adjustments. This represents changes to player winning percentage based on differences in player performance across different contexts.
Intra-Game compares the relative importance of situations across games.
Combined context, then, is the product of inter-game and intra-game context.
Inter-game Win Adjustments measure differences in performance depending on the inter-game context of the performance. In effect, Inter-Game Win Adjustment measures how "clutch" a player was.The impact of context on player value is discussed in some detail in an article I wrote which compares the 2005 seasons of David Ortiz and Alex Rodriguez That article can be found here.
Intra-game Win Adjustments measure differences in performance depending on the intra-game context of the game.
Expected Win Adjustment measures a player's expected intra-game win adjustment based on the player's (context-neutral) winning percentage. Expected Win Adjustment helps adjust for the non-linear effect of player performance on team winning percentage.
Player Game LogThe Player Game Log provides links to every game in which a player played for which I have calculated Player won-lost records - regular-season and postseason. Clicking on the "+" in front of a season will display all of the player's games for that season, in chronological order. The teams, score, and date are shown - clicking on this will open the Game Page for that game - as well as pWins, pLosses, and net pWins (pWins minus pLosses) for the player in each game.
Most Similar PlayersThe Most Similar Players page identifies the players most similar to the player of interest as measured by Player won-lost records.
First, one can vary the number of players shown.All of these options can be selected on the "Most Similar Players" page by filling in the appropriate boxes and clicking the "Go" button.
Second, one can compare Player won-lost records over a specific age range.
Third, one can choose to include pWins (which tie to team wins and hence incorporate context) or not. The default option is to include pWins (over positional average and replacement level) in the comparison (along with eWins).
Fourth, one can normalize season lengths (to 162 games) for all players and/or extrapolate missing player games before making comparisons. The default option is to not normalize season lengths or extrapolate missing games.
Finally, one can assign unique weights for the six factors that are used for comparison: Batting, Baserunning, Pitching, Fielding, eWins, and pWins. The default weights are one for each of the six factors. Note that if the "context" option is set to "n" (No), the weight on pWins will be zero, regardless of what is entered here.
Value DecompositionThe Value Decomposition table decomposes a player's value into its constituent parts, by season and for the player's career as a whole.
Clicking the "Value Decomposition" link on the pWins table decomposes pWORL; clicking the "Value Decomposition" link on the eWins table decomposes eWORL. One can switch from one to the other by adding or subtracting "&p=1" to the end of the filename: including "&p=1" will open the pWORL version of the Value Decomposition page, excluding that term will open the eWORL version. The first table here shows the player's wins relative to average in the four aspects at which a player can earn Player wins: Batting, Baserunning, Pitching, and Fielding. The headings of these four columns link to the player's Batting, Baserunning, Pitching, and Fielding pages, respectively. These tables are described next. For batting and baserunning, the "average" against which these are measured is non-pitcher average. For pitching and fielding, average is simply a .500 winning percentage.
The final column of this table sums the totals for these four aspects. For the version of this table based on eWins, the results here are context-neutral and teammate-adjusted. For the version of this table based on pWins, these numbers are context-dependent.
The first column of this second table, headed "Positional Adjustments", adjusts for the player's positional average. Positional averages adjust for differences in average player performance across different positions. A negative number indicates a positional average over .500 (so that a player's wins over positional average are less than his wins over .500); a positive number indicates a positional average below .500.
The second column of the second table shows Wins over Positional Average (WOPA), which is equal to the sum of the last column of the first table and the first column of the second table.
The next-to-last column, then, presents "Replacement Value". Replacement Value is simply the difference between WORL and WOPA. In effect, this measures the raw value of playing time.
The final column, then, is equal to the sum of the two preceding columns, Wins over replacement level, WORL.
BattingThe Batting player page shows details of a player's batting record by component. Player won-lost records are calculated via nine components. These are described in my basic article explaining the calculation of Player won-lost records here.
Context measures the relative importance of the situations in which the Player performed. Average context is equal to 1.0 by construction.
Inter-Game compares the relative importance of situations within the same game. Inter-Game context is identical to the concept of Leverage.Win Adjustments represent changes to player winning percentage based on differences in player performance across different contexts.
Intra-Game compares the relative importance of situations across games.
Inter-game Win Adjustments measure differences in performance depending on the inter-game context of the performance. In effect, Inter-Game Win Adjustment measures how "clutch" a player was.
Intra-game Win Adjustments measure differences in performance depending on the intra-game context of the game.
BaserunningThe Baserunning player page shows details of a player's baserunning record by component. Player won-lost records are calculated via nine components. These are described in my basic article explaining the calculation of Player won-lost records here.
Context measures the relative importance of the situations in which the Player performed. Average context is equal to 1.0 by construction.
Inter-Game compares the relative importance of situations within the same game. Inter-Game context is identical to the concept of Leverage.Win Adjustments represent changes to player winning percentage based on differences in player performance across different contexts.
Intra-Game compares the relative importance of situations across games.
Inter-game Win Adjustments measure differences in performance depending on the inter-game context of the performance. In effect, Inter-Game Win Adjustment measures how "clutch" a player was.
Intra-game Win Adjustments measure differences in performance depending on the intra-game context of the game.
PitchingThe Pitching player page shows details of a player's pitching record by component. Player won-lost records are calculated via nine components. These are described in my basic article explaining the calculation of Player won-lost records here.
Context measures the relative importance of the situations in which the Player performed. Average context is equal to 1.0 by construction.
Inter-Game compares the relative importance of situations within the same game. Inter-Game context is identical to the concept of Leverage.Win Adjustments represent changes to player winning percentage based on differences in player performance across different contexts.
Intra-Game compares the relative importance of situations across games.
Inter-game Win Adjustments measure differences in performance depending on the inter-game context of the performance. In effect, Inter-Game Win Adjustment measures how "clutch" a player was.
Intra-game Win Adjustments measure differences in performance depending on the intra-game context of the game.
FieldingThe Fielding player page shows details of a player's fielding record by position. The first table shows the player's total fielding wins, losses, winning percentage, and fielding wins over replacement level, across all fielding positions, by season and for the player's career (regular-season only). The same data are also shown for the player's "primary" position. The player's primary position is determined as the position for which the player earned the most total (regular-season) career fielding decisions.
Context measures the relative importance of the situations in which the Player performed. Average context is equal to 1.0 by construction.
Inter-Game compares the relative importance of situations within the same game. Inter-Game context is identical to the concept of Leverage.Win Adjustments represent changes to player winning percentage based on differences in player performance across different contexts.
Intra-Game compares the relative importance of situations across games.
Inter-game Win Adjustments measure differences in performance depending on the inter-game context of the performance. In effect, Inter-Game Win Adjustment measures how "clutch" a player was.
Intra-game Win Adjustments measure differences in performance depending on the intra-game context of the game.
Postseason RecordThe Postseason Record page presents a player's Player won-lost record in postseason games. The first table shows pWins, pLosses, eWins, and eLosses, as well as winning percentages based on both sets of numbers. Data are shown by season and for the player's career.
The first three columns of numbers present game context multipliers. These measure the relative importance of the situations in which the Player performed. Average context is equal to 1.0 by construction.
Inter-Game compares the relative importance of situations within the same game. Inter-Game context is identical to the concept of Leverage.The last two columns present what I call win adjustments. This represents changes to player winning percentage based on differences in player performance across different contexts.
Intra-Game compares the relative importance of situations across games.
Combined context, then, is the product of inter-game and intra-game context.
Inter-game Win Adjustments measure differences in performance depending on the inter-game context of the performance. In effect, Inter-Game Win Adjustment measures how "clutch" a player was.
Intra-game Win Adjustments measure differences in performance depending on the intra-game context of the game.
First, one can change how the players' seasons line up: by Age, by Experience, or by Year. You don't have to type the full words in the box here (although you can): you can simply type "a" for Age, either "e" or "x" for experience, or "y" for year (without the quotation marks in all cases).
Second, one can vary the records compared. There are six options. The first two of these are overall records: pWins, which tie to team wins, or eWins, which are adjusted to neutralize context and control for teammate-ability. These comparisons show Player wins, losses, and wins over positional average (WOPA) and replacement level (WORL).
In addition to total Player won-lost records, one can also compare player won-lost records in the four aspects of the game in which player wins are earned: Batting, Baserunning, Pitching, and Fielding. In these cases, the numbers shown are context-neutral and teammate-adjusted.
The Player Comparison tool accepts the following abbreviations for the six player record options: pw (for pWins), ew (for eWins), bat (for batting), r or run (for baserunning), pitch (for pitching), and f or field (for fielding). Or, you can type out any of the options in full (as they appear on the Player Comparison page).
There are three additional options below those: including postseason games, normalizing season lengths, and extrapolating missing games. Additional details on some of these options are discussed in some more detail below.
Finally, one can choose the time period over which positional averages are calculated. This is an option on most stat pages. Options for positional averages are 0.500 for all positions, or position-specific averages calculated over one year, nine years (the year of interest plus four years prior and four years after, if available), or all seasons for which Player won-lost records are calculated (currently 1916 to 2019). For pitchers, one can also choose how to calculate positional averages for starting vs. relief pitchers (0.500 for both, empirical - i.e., overall record for all starters vs. overall record for all relievers, or empirical only for those pitchers who did both in the same season). Positional averages are discussed in more detail here.
For Batting and Baserunning, the Player Comparison tool shows what it calls "WOPA_b". WOPA_b measures (batting or baserunning) wins relative to a league-average non-pitcher. This allows one to compare players in DH leagues (where non-pitcher league average will be 0.500) with players in non-DH leagues, where raw offensive winning percentages of position players are boosted by having their offense compared, in part, to pitchers' offense.Here is a fielding comparison of Frank Thomas and Ozzie Smith.
For Pitching, the Player Comparison tool shows wins over positional average, WOPA, where separate positional averages may be calculated for starting pitchers and relief pitchers.
For Fielding, the Player Comparison tool shows what it calls "WORL_f". This measures Fielding wins over a player's overall replacement level. The purpose of this comparison is to enable one to compare fielders at different positions. Players at more difficult defensive positions will tend to have lower replacement values against which they are compared.
For this comparison, I use replacement level instead of positional average to highlight the idea that, for example, a below-average defensive shortstop is nevertheless providing his team with positive value merely by playing shortstop. A player with a positive value of WORL_f (as most players have) is a player who is more valuable playing the field (if one uses WORL as one's measure of player value) than not. On the other hand, it is possible for a player to be such a poor fielder that his fielding value "over replacement" may actually be negative, suggesting that such a player would have been more valuable as a DH (or PH) than by trying to play a defensive position. For his career, Frank Thomas was an example of such a player.
Ozzie Smith | Frank E. Thomas | |||||||||
Age | Games | eWins | eLoss | Win Pct. | WORL_f | Games | eWins | eLoss | Win Pct. | WORL_f |
---|---|---|---|---|---|---|---|---|---|---|
22 | 60 | 0.7 | 0.9 | 0.438 | -0.1 | |||||
23 | 159 | 8.0 | 8.0 | 0.498 | 0.7 | 158 | 0.8 | 1.0 | 0.433 | -0.1 |
24 | 156 | 7.4 | 6.7 | 0.525 | 1.4 | 160 | 2.9 | 3.5 | 0.458 | -0.2 |
25 | 158 | 7.8 | 7.1 | 0.524 | 1.4 | 153 | 1.7 | 2.5 | 0.400 | -0.6 |
26 | 110 | 5.1 | 4.6 | 0.526 | 1.0 | 113 | 1.4 | 1.4 | 0.501 | 0.2 |
27 | 140 | 7.6 | 6.1 | 0.555 | 2.2 | 145 | 1.5 | 1.5 | 0.491 | 0.1 |
28 | 159 | 7.4 | 6.2 | 0.547 | 1.9 | 141 | 1.9 | 2.2 | 0.473 | -0.0 |
29 | 124 | 6.7 | 6.1 | 0.526 | 1.3 | 146 | 1.3 | 1.4 | 0.485 | 0.1 |
30 | 158 | 8.5 | 7.2 | 0.541 | 2.0 | 160 | 0.2 | 0.3 | 0.351 | -0.1 |
31 | 153 | 6.2 | 5.7 | 0.522 | 1.1 | 135 | 0.5 | 0.6 | 0.483 | 0.0 |
32 | 158 | 6.8 | 5.1 | 0.574 | 2.3 | 159 | 0.4 | 0.4 | 0.513 | 0.1 |
33 | 153 | 7.1 | 5.6 | 0.559 | 2.1 | 20 | 0.0 | 0.1 | 0.134 | -0.1 |
34 | 155 | 6.3 | 5.6 | 0.531 | 1.3 | 148 | 0.1 | 0.1 | 0.317 | -0.1 |
35 | 143 | 5.3 | 4.3 | 0.555 | 1.5 | 153 | 0.3 | 0.4 | 0.407 | -0.1 |
36 | 150 | 5.9 | 5.4 | 0.523 | 1.1 | 74 | 0.1 | 0.0 | 0.553 | 0.0 |
37 | 132 | 6.1 | 5.3 | 0.534 | 1.3 | 34 | 0.0 | 0.0 | 0.0 | |
38 | 141 | 6.2 | 5.9 | 0.510 | 0.8 | 137 | 0.0 | 0.0 | 0.0 | |
39 | 98 | 4.0 | 3.6 | 0.527 | 0.8 | 155 | 0.0 | 0.0 | 0.0 | |
40 | 44 | 1.8 | 1.6 | 0.532 | 0.4 | 71 | 0.0 | 0.0 | 0.0 | |
41 | 82 | 2.4 | 2.1 | 0.531 | 0.5 | |||||
------ | ------ | ------ | ------ | ------ | ------ | ------ | ------ | ------ | ------ | ------ |
CAREER RECORDS | 2,573 | 116.6 | 102.0 | 0.533 | 25.0 | 2,322 | 13.7 | 16.4 | 0.456 | -1.1 |
Treatment of Postseason WinsIn 2010, Roy Halladay made his 33rd start of the season in the Philadelphia Phillies' 157th team game. Halladay left that game healthy. Based on the 5-man rotation used that season by the Phillies, Halladay was in line to start the Phillies' final regular-season game of the season.
Normalizing Season LengthMy Player won-lost records are constructed on a game-by-game basis. In the case of pWins and pLosses, the number of total player decisions is exactly equal to three per team game. Hence, my work implicitly values each game the same. Rather than considering individual games to be of equal value, however, it might make more sense to think of individual seasons as being of equal value.
162-Game SeasonFirst, prior to 1961 in the American League and 1962 in the National League, seasons were 154 games long. Since 1962 (1961 in the AL), seasons have been 162 games long. Eight games may not seem like much, but over the course of a 20-year career, an additional 8 games per season adds up to another full season (20*8 = 160).
Labor StoppagesSecond, there have been regular-season games missed due to labor strikes during four seasons in major-league history: 1972, 1981, 1994, and 1995. The first of these was relatively short, reducing season lengths by about 7 games on average (teams played 153 - 156 games that year). The last reduced season length by exactly 18 games per team (teams played a 144-game schedule in 1995). The middle two were particularly bad, costing teams 50 or more games each season and, in the latter case, eliminating the postseason as well. There were no players whose careers were affected by all three (1994-95 was a single work stoppage) of these work stoppages, but even for players affected only by the 1994-95 strike, the lost games added up to nearly half a season. For players affected by both the 1981 and 1994-95 strikes, the lost games added up to nearly a full season.
Year | Games Played |
---|---|
1979 | 6 |
1980 | 15 |
1981 | 88 |
1982 | 156 |
1983 | 156 |
1984 | 160 |
1985 | 150 |
1986 | 151 |
1987 | 139 |
1988 | 109 |
1989 | 145 |
1990 | 130 |
1991 | 155 |
1992 | 144 |
1993 | 115 |
1994 | 100 |
1995 | 133 |
1996 | 59 |
1997 | 74 |
1998 | 109 |
1999 | 58 |
2001 | 51 |
2002 | 97 |
Year | Games Played |
---|---|
1979 | 6 |
1980 | 15 |
1981 | 132 |
1982 | 156 |
1983 | 155 |
1984 | 161 |
1985 | 151 |
1986 | 152 |
1987 | 139 |
1988 | 108 |
1989 | 145 |
1990 | 130 |
1991 | 155 |
1992 | 144 |
1993 | 115 |
1994 | 143 |
1995 | 149 |
1996 | 59 |
1997 | 74 |
1998 | 109 |
1999 | 58 |
2001 | 51 |
2002 | 97 |
Missing Play-by-Play DataThe third potential issue with games played is unique to Player won-lost records, rather than to the actual seasons played. My Player won-lost records are only calculated based on games for which Retrosheet has released play-by-play data. Unfortunately, Retrosheet is missing some games in seasons prior to 1928. Missing games are not uniform, but are worse for some teams than others. The exact games missing by season and by team are detailed here.
Adjustments Based on Season LengthMy Player Comparison tool allows two types of adjustments based on season length.
First, one can normalize the number of team games to adjust for differences between 154-game and 162-game schedules and to account for games lost due to strikes. Entering "y" in the "Normalize Season Length (y/n)" box will normalize all seasons to 162 games.The default position of the Player Comparison tool is to not adjust for either season length or missing player games.
Second, one can extrapolate missing player records for games for which Retrosheet has not yet released play-by-play data. Entering "y" in the "Extrapolate Missing Player Games (y/n)" box will adjust Player won-lost records based on the total number of actual games played by the player for those seasons (prior to 1928) for which Retrosheet may be missing play-by-play data for some games.
While extrapolating Player won-lost records in this way can be helpful to try to get a general sense of how players might compare, the resulting numbers are, of course, merely an estimate, based on an implicit assumption that the player(s) performed exactly as well in the missing games as in games for which play-by-play data are available. Nevertheless, I think that this can be a helpful addition to my Player comparison tools.
A comparison of Barry Bonds and Babe Ruth with seasons normalized to 162 games and missing player games extrapolated (for Ruth) can be found here. Note that it is only possible to extrapolate games for seasons for which Retrosheet has released partial play-by-play data. Hence, the comparison here still excludes the earliest seasons of Babe Ruth's Red Sox career.
Team Franchise PageIf no season is specified, a Team Franchise page will be shown. At the top of the Team Franchise table, one can select a specific season, which will pull up a Team Page (as described below).
Team PageIf a specific season is chosen, the season-specific team page will appear. On this page, the line under the name of the team is a link to "Traditional Statistics and Splits" for the team at Retrosheet. The third line provides a link to the team's franchise page (which is described above).
The first table on the team page presents Player won-lost records for position players. Players are sorted by pWins over replacement level (pWORL). In addition to pWORL, player records are shown for pWins, pLosses, pWOPA, eWins, eLosses, eWOPA, and eWORL.
The second table on the player page mirrors the first table, but for pitchers. Players are again sorted by pWORL.
Below these two tables are team totals for the same statistics.
The next three tables somewhat parallel the previous three tables, but show (context-neutral) wins, losses, and winning percentages decomposed into Batting, Baserunning, Pitching, and Fielding. Separate tables are presented for position players, pitchers, and team totals. Players are sorted by total pWORL in this table, so that the players are presented in the same order as in the first two tables.
The next set of tables presents players and their player won-lost records by position. Two sets of tables are shown by position. The first set of these tables show eWins, eLosses, and eWOPA earned by players at the relevant position. Players are sorted in these tables by eWins earned at the position of interest. Team wins over positional average (eWOPA) by position are then summarized in a single table. These tables are then repeated for pWins, pLosses, and pWOPA by position.
Postseason Team PageFor teams which made the postseason in a particular season, their regular-season team pages include a link to a Postseason Team Page.
The first three tables on the Postseason Team Page parallel those on the regular-season page. The first shows Player won-lost records for position players. Position players are sorted by pWins. Records are shown for pWins, pLosses, eWins, and eLosses. The second table shows the same statistics for pitchers. Below these two tables, then, are team totals for the same statistics.
Below these summary tables are separate tables for each playoff round. These list pWins and pLosses by round by player, with players sorted by pWins.
The first table shows the probabilities of stolen bases, caught stealings, and wild pitches (and passed balls) by outs and baserunners.
The second table shows the ex ante probabilities of basic events - out, single, double, triple, and double play - based on the final result for balls in play.
The third table shows the ex ante probability of an out made by fielding position, based on the final result for balls in play.
The fourth table shows the ex ante probability of each fielding position being the first fielder on a ball, based on the final result for balls in play.
The final two tables, then, show the probability of baserunner outs and baserunner advancement by baserunner based on the type of play.
Positional AveragesAt the top of the Leaders page, as at the top of most stat pages, one can choose the time period over which positional averages are calculated. This is an option on most stat pages. Options for positional averages are 0.500 for all positions, or position-specific averages calculated over one year, nine years (the year of interest plus four years prior and four years after, if available), or all seasons for which Player won-lost records are calculated (currently 1916 to 2019). For pitchers, one can also choose how to calculate positional averages for starting vs. relief pitchers (0.500 for both, empirical - i.e., overall record for all starters vs. overall record for all relievers, or empirical only for those pitchers who did both in the same season). Positional averages are discussed in more detail here. Note that the choices made here will only matter for leaderboards which are centered on wins over positional average (WOPA) and/or replacement level (WORL).
Time Period to be AnalyzedThe first four lines allow one to choose the grouping for the leaderboards. One can create single-season leaderboards by entering a league name in the first box. Enter the year and either "A" for American League (any word that starts with an "A" - or "a" - will work) or "N" for National League (any word that starts with an "N" or an "n" will work). If the American or National League is not specified, leaders will be shown for the entire major leagues for the season chosen.
Statistics to Show for Leaders and TrailersThe next seven lines provide options for which leaderboards can be created.
Regular Season OnlyThe first five lines are based on regular-season statistics only.
Statistics including Postseason
Leaders in pWins, pWOPA, and pWORL across all postseason series, or by individual series, can be shown by clicking the relevant link on this line.Postseason (Players only)
Leaders in total wins, WOPA, and WORL including both regular-season and postseason games can be tabulated based on either pWins or eWins from the final row of leaderboard options.Total Wins (Regular Season plus Postseason)
The main body (left-hand side) of the Article List page shows the most recently written articles.
To the right of the main body are links to additional articles and article lists.
The "Additional Articles" link opens a page which shows all articles available on the website, organized into five general categories:The last of these - "Older Articles" provide links to articles which were written before the significant changes to Player won-lost records in the summer of 2019 which are described here.
- Articles about Players
- Articles about Seasons
- Analytical Articles
- Other Articles
- Older Articles
Below the "Additional Articles" link are direct links to the several key articles which explain Player won-lost records.The last two articles shown on the right-hand side of the "Article List" page discuss the seasons over which Player won-lost records are calculated and what games are missing from some of the earliest seasons and provide a Glossary of terms which I use on my website (and in my books). All articles are written so that they pull data directly from the most recent version of the Player won-lost database. In some cases, this could lead to a disconnect between the text and data presented in some older articles.
- Baseball Player Wins and Losses: The Basics explains how Player won-lost records are calculated
- "Overview of Website" is the article you're currently reading.
- "Comparing Players" is a 53-page PDF which looks at how to compare players using Player won-lost records with a primary focus on positional averages.
- "Calculating Customized Value Statistics" describes how to construct a user-defined "Uber Statistic" to rank players using this page.