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— Where BTF's Members Investigate the Grand Old Game
Monday, August 19, 2002
Win Values: A New Method to Evaluate Starting Pitchers - Part 3
In this section, I will present some high level Win Value results.? Hopefully, these results will give the reader a comfort level that my new system does make sense.? In addition, the reader will be able to see how Win Values integrate run prevention and W-L information.
Table 1 presents the top Win Value seasons in 1978-2001, the seasons for which the required detailed data are available.
Table 1: Top Win Values in 1978-2001
The table presents the 22 seasons in which a pitcher has a Win Values of more than 5.50.? You can see that the pitchers with the highest Win Values are indeed the pitchers who are generally considered to have had the best seasons in the past 25 years.? Gooden in 1985, Maddux in 1995, Clemens in 1990 and 1997, Pedro in 1997, 1999 and 2000, Guidry in 1978, etc.? The foursome of Maddux (3), Clemens (4), Martinez (3), and Randy Johnson (4) have 14 of the best 22 seasons since 1977.
Now that we have seen that the Win Value system is able to identify the best seasons, let?s see how Win Values handles some tougher calls.? Remember that Win Values integrate run prevention information (e.g., ERA+) with W-L information.? The results of this integration can be reviewed in the next two tables of pitchers with contrasting information.? Table 2 presents a sampling of notable recent pitching seasons with very good W-L records and mediocre ERA, especially when compared to the W-L record.
Table 2: Win Values of Notable Good W-L/Mediocre ERA in 1978-2001
You will note that, in general, Win Values for these ?lucky? pitchers are higher than their WAA figures.? Win Value gives some reward for keeping the game close, for keeping the team in the game, etc.? A pitcher with a mediocre ERA+, and therefore a mediocre WAA, can have a fairly decent Win Value total if he managed to maximize his contributions.?
A pitcher with a league average ERA could well have helped a team significantly.? Consider this hypothetical pitcher?s game scores (runs scored-runs allowed): 4-3, 1-7, 3-2, 2-9, 6-4, 2-1, and 13-5.? In his seven starts, the pitcher?s team scored 31 runs and he allowed 31 runs.? However, due to the fact that he often gave up few runs when his team scored few runs, and pitched poorly when his team scored a lot of runs (or sometimes when they scored few runs), he managed to go 5-2 despite a league average ERA and league average run support.
This is another case of where backwards Bayesian reasoning may provide insights.? We know that a pitcher who regularly keeps his team in the game can make a significant contribution to his team, since he gives his team a chance to win many of his starts.? We can turn around that inference and infer that a pitcher?s W-L record may be a reflection of how well he managed to allocate his runs allowed throughout his starts vis a vis his team?s run support in those games.? That is, a pitcher with a better W-L record than his ERA may well have done a good job of runs management and therefore really might have contributed more to his team winning than his ERA reflects.?
Table 3 presents the other side, recent pitchers who had very good ERA?s but were unable to convert their good pitching into stellar W-L records.? These ?unlucky? guys may well have done a poor job of runs management.
Table 3: Win Values of Notable Good ERA/Mediocre W-L in 1978-2001
Generally speaking, the Win Values for these ?unlucky? pitchers are less than their WAA totals.? The reasoning is similar to that above.? These pitchers generally did a poor job of runs management, such as pitching well when their team scored a lot of runs or pitching poorly when their team scored an average number of runs.? Ultimately, then, by looking at the game-by-game performances, Win Values is able to reflect these pitchers? ?failure? whereas WAA may well be unduly impressed with their seasonal ERA?s.
An ?unlucky? pitcher with a league average ERA may well have contributed significantly less than his ERA would suggest if he does a poor job of matching runs allowed to his run support.? As a parallel to the illustrative ?lucky? pitcher above, consider a pitcher whose team plays the following seven games: 4-5, 1-2, 3-1, 2-4, 6-7, 2-9, 13-3.? Here the team goes 2-5 rather than 5-2, despite the fact that the team scored and allowed exactly the same number of runs on a game-by-game basis, only the runs scored and runs allowed pairs were intermixed.
In this section we have seen the high-level Win Value results.? We saw that the best seasons over the past 25 years according to Win Values were indeed the best seasons, such as Gooden in 1985, Maddux in 1995, Clemens in 1990 and 1997, Pedro in 1997, 1999 and 2000, Guidry in 1978, etc.
We also saw that Win Values integrate run prevention information with W-L information to evaluate a pitcher?s performance.? Generally speaking, when there is a conflict between a pitcher?s W-L and ERA, Win Values takes the middle ground.? We saw that pitchers with good W-L records but mediocre ERA?s often have larger Win Values than WAA; conversely, pitchers with mediocre W-L records but good ERA?s often have smaller Win Values than WAA.? The explanation is that Win Values is able to recognize the pitcher?s runs management, rewarding those who contribute the most to their team while penalizing those who contribute the least to their team.
? The 1978-1990 and 1999-2001 data used here was obtained free of charge from and is copyrighted by Retrosheet.? Interested parties may contact Retrosheet at 20 Sunset Rd., Newark, DE 19711.? I want to thank the efforts and support provided by the Retrosheet organization, especially Dave Smith, Tom Ruane, and Ray Kerby who were all very helpful to me.? I also want to thank STATS, Inc. of Morton Grove, IL who provided me with the 1991-1998 data.? The WAA data was graciously provided by Justin Kubatko to whom I am also very grateful.
? All ERA+ data used in the article are from Total Baseball-VII, with the exception that the 2001 ERA+ figures are from Baseball-Reference.com.
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