— Where BTF's Members Investigate the Grand Old Game
Thursday, April 10, 2003
Win Values 2002
Did Barry Zito really deserve the Cy Young Award?
Last year I introduced a new stat to measure the value that a starting pitcher brought to his team on a game-by-game basis. In short, win values assigns a number between -1 and +1 to each starting pitcher for each game to reflect how well the pitcher performed given the run support he was provided. The win value figure is the difference in probabilities that the starting pitcher?s team would have won the game given its offensive run support with the pitcher?s performance compared to if a league average pitcher would have started in his place.
As an example, a pitcher who wins a game 1-0 is earns a very high number of win value points since his team would very likely have lost the game (scoring only 1 run) with league average pitching. On the other hand, a pitcher who wins a game 10-0 earns only a few win value points since his team would very likely have won the game (scoring ten runs) with league average pitching. A complete description of the win value methodology and results from previous seasons is available here.
Top AL Starting Pitchers in 2002
Retrosheet just released the play-by-play data for the 2002 season. Thus, I am now able to calculate the starting pitcher win values for last season. The following table presents the top ten starting pitcher performances according to win values in the American League.
I wish to thank David Smith, Tom Ruane, Ray Kerby, Tangotiger, and all the Retrosheet volunteers for making available the 2002 season data.
Table 1: 2002 AL Win Value Leaders
The entries in the table are the pitcher?s won-loss record, his park-adjusted ERA relative to league, his wins above average (which is based solely upon his ERA+ and number of innings pitched), his win values relative to a league average pitcher, and his win values relative to a replacement level pitcher. Bartolo Colon?s stats reflect his pitching in both leagues last season; Colon accumulated 2.78 win values relative to league average in the AL and 1.21 win values in the NL.
As you know, Barry Zito won the 2002 AL Cy Young award, largely due to his 23-5 record. Pedro Martinez finished second in the voting, with Derek Lowe third; the only other pitcher to appear on a ballot was Jarrod Washburn who got a lone third place vote.
Win values suggests that the AL pitcher who contributed the most to his team last season was Tim Hudson, a pitcher who did not even appear on a single Cy Young ballot. The reason, of course, is that Huddy only went 15-9 and Cy Young voters are enamored with a pitcher?s won-loss record.
A game-by-game look at Hudson?s season reveals why win values tabs it as the best in the AL.
Table 2: Tim Hudson?s 2002 Game-by-Game Win Values
* Last inning Tim Hudson appeared in (partial innings, including facing one or more batters without recording an out, count as a full inning).
** The score at the conclusion of both halves of the last inning Hudson appeared in; Oakland?s score is given first.
Let me describe Hudson?s first game to make sure the reader understands what is being reported in the table. The first row indicates that Hudson?s first start of the season was at home against Texas on April 2. Hudson pitched into the 7th inning, and the score at the conclusion of the 7th inning was 2-1 in favor of Oakland. The A?s won the game 3-2 (details below). Hudson got a no-decision in the game. Hudson?s performance was worth .370 win value points. That is, Hudson put the A?s into a position (leading 2-1) in which his team had a .370 higher probability of winning the game after 7 innings than if a league average pitcher had started that day for Oakland.
You will see that Hudson?s hard luck stayed with him for the entire season. Games in which Hudson pitched very well but came up without a victory include the following.
By my count, if neither team had scored any more runs after Hudson left each of his starts, he would have gone 21-9 (with four ties). Since he actually went 15-9, it is clear that Hudson?s bullpen mates cost him several victories. In short, Hudson?s W-L record does not do justice to how great a season he actually had.
Barry Zito, Pedro Martinez, and Derek Lowe each had better ERA+ and better W-L records than did Hudson. So how can their win value be lower?
Seasonal averages can mask a myriad of issues that a detailed game-by-game analysis can take into account. Zito pitched very well last year but there were several games in which his team did not need him to pitch so great. For example, here are the scores in six of Zito?s starts when he left the games: 10-3, 11-1, 9-3, 7-0, 7-1, and 8-1. Even with a league average pitcher, the A?s would likely have won these games, and accordingly Zito is given little credit for winning these games.
Similarly, in five of Derek Lowe?s starts the Red Sox outscored the opposition 49-0 when Lowe was the pitcher of record (10-0, 9-0, 9-0, 10-0, and 11-0). Obviously Lowe pitched great in these games but receives little win value credit since his run support was so high in each of these games. This is an illustration that win values is a "value" stat (backward looking) rather than an "ability" stat (forward looking).
Pedro Martinez had another outstanding season in 2002. The main reason why he doesn?t finish higher on the win value ladder is that Pedro only started 30 games last season. Contrast that to Zito?s 35 and Hudson?s 34. I am confident had Pedro started 34 or 35 games, he would have had the league?s highest win value total. The Red Sox rightfully protect their franchise pitcher?s arm, so I am not suggesting that they pitch Pedro more; I am merely pointing out why he finished fourth in win values.
Martinez and Lowe illustrate another issue related to how win values are calculated. In the win value system, as in WAA, Pete Palmer?s TPI, and Michael Wolverton?s SNW, the pitcher is given total credit for run prevention, be it via the strikeout or the groundout. Thus, Pedro receives no additional credit for being such a dominating strikeout pitcher (nor do Clemens, Johnson, Seaver, et al.).
Barry Zito, Pedro Martinez, and Derek Lowe all had outstanding seasons in 2002. However, according to win values, none contributed more to his team winning (in a probabilistic sense) than did Tim Hudson.
Top NL Starting Pitchers in 2002
Table 3 presents the top ten National League starting pitchers according to win values.
Table 3: 2002 NL Win Value Leaders
Randy Johnson dominated the NL once again in 2002 (especially in light of Curt Schilling?s late-season slide) and unanimously won his 4th consecutive and 5th overall Cy Young award. Schilling was a near-unanimous second place finisher. John Smoltz and his 55 saves came in third for the Cy Young. Roy Oswalt tied Eric Gagne for fourth.
We don?t need to spend a lot of time discussing the NL. Any evaluation tool that claims someone other that Randy Johnson was the best starting pitcher in the NL last season is highly suspect. However, it is worth noting that Curt Schilling and Randy Johnson were virtually tied in win values after Schilling?s September 15 start. That night Byung-Hyun Kim blew a save in the ninth or else Schilling would have gone to 24-5 (Johnson was 22-5 at the time). Johnson closed out the season with two great victories whereas Schilling?s last two starts were both struggling losses.
Greg Maddux had another great season last year and, due to Schilling?s late season fade, actually finished second in win values in 2002. In the next section of the article, I will update Johnson, Maddux and the other top active pitchers? career win value totals to include the 2002 figures.
Updating Top Active Pitchers? Career Win Values
In my previous article, I presented a table of the greatest starting pitchers of the last thirty years, the seasons for which Retrosheet has made available the play-by-play data, according to win values.
Below, I update the active pitchers included in that table to incorporate their 2002 seasons. Note that the table is sorted by career win values relative to replacement level, though win values relative to league average are also presented.
Table 4: Win Values for Top Starters of Last 30 Years
Roger Clemens is deemed to be the greatest starting pitcher in the last 30 years, both in win values relative to replacement level and in win values relative to league average. At this point in his career, Clemens is treading water, so he?ll likely not add much to his totals.
Greg Maddux is still one of the best pitchers in the majors, and has a good shot of surpassing Clemens in the next two seasons.
Although Randy Johnson has not yet cracked the top ten in win values relative to replacement, he is currently fourth in win values relative to league average, and may well eclipse Tom Seaver to move into third place in this measure before he retires.
Pedro Martinez is the other member of this modern quartet (sure-fire Hall of Famers). Pedro is still in mid-career, so he hasn?t yet accumulated a ton of win values relative to replacement, at least compared to pitchers who pitched for 20 years. On the other hand, the meteoric first-half of Pedro?s career (highest ERA+ in history) yields the sixth highest win values relative to league average, behind only Clemens, Maddux, Seaver, Johnson, and Palmer.
Other active pitchers who are making inroads on the list of the best modern starters include Tom Glavine, Kevin Brown, Chuck Finley, Mike Mussina, the recently revived David Cone, Kevin Appier, Curt Schilling, John Smoltz (now a closer), and David Wells. Conventional wisdom puts Glavine into the Hall of Fame, and none of the other guys as of now, though Mussina will likely have a solid case before he ultimately retires.
In this article I have presented updated results of my new win value system that evaluates starting pitchers. Thanks to the wonderful volunteers at Retrosheet, the required data for the 2002 season recently became available. Thus, I have calculated win values for each league for last season.
We saw that Randy Johnson contributed the most among NL starting pitchers to his team in 2002, and deservedly won his 4th consecutive and 5th overall Cy Young award. In the AL, on the other hand, win values suggests that Tim Hudson, a pitcher who did not appear on a single Cy Young ballot, contributed the most among AL starting pitchers. As always, Cy Young voters and the general public place too much emphasis on a pitcher?s won-loss record.
Many sophisticated analysts disregard a pitcher?s W-L record altogether and instead focus entirely upon ERA (ERA+). I have found that there may be valuable information in a pitcher?s W-L record, especially looking backward. Accordingly, I developed the win values system to be the best integration of W-L and ERA+ data when attempting to determine how much the pitcher contributed to his team. In my system, run prevention is critical but its value in helping a team win must be measured in the context of the number of runs the team?s offense scores.
Comments on the method or the 2002 results are encouraged.