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Tippett and DIPS (August 1, 2003)

Posted 4:46 p.m., August 1, 2003 (#10) - kamatoa
  Regardless of whether one believe Tom Tippett made an important contribution or not to McCracken's work (I happen to think he added a lot to the conversation on BABIP), his approach toward other researchers and his critics is impressive. It was a class act to cite both Voros's and Woolner's follow-up work and he was even-handed in answering his work's critics.

Not having played Diamond Mindh, I'm not sure how adding BABIP to the game will affect outcomes - if I read Tippett's evidence right, the variance accounted for in any ability to affect BABIP is pretty negligible for all but the most extreme outliers (knuckleballers included in the outlier category). Would accounting for pitchers' ability to affect BABIP truly influence a projection system to the point that it would affect outcomes? From a theoretical standpoint, the possibility to affect BABIP is interesting - from a practical standpoint, how much can the discovery of this minor ability affect accurate prediction? It seems that the error variance here is larger than the variance explained by the actual effect.

Although Tippett presented some interesting examples in his original article that showed an apparent ability - I'm also wondering what the population mean would be. That is - what is the average ability of a pitcher to prevent BABIP. If it's close to zero, then that could also mean that, in aggregate, bringing BABIP into the equasion wouldn't add much to a prediction system.

Tippett and DIPS (August 1, 2003)

Posted 5:06 p.m., August 1, 2003 (#14) - kamatoa
  Patriot,

I learned from Tippett's article that there is a minor ability for pitchers to affect BABIP. Although this ability may be impractically small, Tippett's data set had so much power that he was able to detect it. On the other hand, why do you think he contradicts Voros? He said here that his research "fully supports several of McCracken's most important observations."

Tippett and DIPS (August 1, 2003)

Posted 5:08 p.m., August 1, 2003 (#16) - kamatoa
  Patriot - I should have read your question better - you weren't asking what Tippett did that contradicts his work, you're asking what people see in Tippett's article that seriously contradicts his work. The answer to that question should probably be "Nothing." Tippett's work supports Voros's, and extends it in interesting, if not earth-shattering, ways.

Tippett and DIPS (August 1, 2003)

Posted 5:14 p.m., August 1, 2003 (#17) - kamatoa
  Patriot:

Nobody has ever concluded that pitchers DIDN'T have some ability over $H. I think most of the "revelations" of the Tippett study are the results of misunderstanding over Voros' work

If people misunderstood Voros' work, Voros might have contributed to that. On the original Tippett thread, Jim R. (Post #15) wrote:

Its amazing the amount of revisionist history that goes on about Voros' statements. I distinctly remember the "hits allowed are not particularly meaningful in the evaluation of pitchers" and "major-league pitchers don't appear to have the ability to prevent hits on balls in play".

I also remember these kinds of comments. Tippett is showing that these comments are incorrect. Although it's possible that Voros overstated his own findings with comments like these, the fact that the original researcher would make these kinds of statements at least shows that Tippett's research was an extension of the findings and not simply redundant.

New postseason odds (August 17, 2003)

Posted 12:39 a.m., August 19, 2003 (#3) - kamatoa
  I still think Dackle's got the Yankees overranked - even at five games back, the Red Sox offense is better than the Yanks', and New York's pitching has started to lose some wheels. I doubt they'll put another two games on Boston, as Dackle predicts. Converted into odds, Dackle has 13-to-1 against Boston taking the division. Although I'm not sure if the Sox can squeeze out all five games, that would be a tempting bet to take.

Sabermetrics Crackpot Index (August 29, 2003)

Posted 10:24 a.m., August 30, 2003 (#16) - kamatoa
  31 - 40 points for comparing those who argue against your ideas to sportswriters, scouts, or Cam Bonifay.

Valuing Starters and Relievers (December 27, 2003)

Posted 4:08 p.m., December 27, 2003 (#4) - kamatoa
  Very interesting argument, but I'm not convinced that relievers and starters should be evaluated separately for the simple reason that a single run given up in a game has the same weight regardless of whether a starter or a reliever allows it.

Because of that, Win Shares and other systems that use a league average benchmark probably are valuing relievers' and starters' contributions toward team wins accurately - it is simply that these systems inherently account for the relative ease of relieving by giving relievers' a relatively greater per-inning score than starters. It would be foolhardy to argue that this difference arises from relievers' greater talent - thus, this difference must arise from the greater difficulty of starting.

To its credit, Win Shares does not indicate that Ligtenberg is more valuable than Schilling - it does, however, note that Ligtenberg contributed to his teams' wins by 1) preventing runs that might have scored and 2) causing outs - the same tasks as required by a starter. In addition, many of Ligtenberg's innings are likely to be "high-leverage" situations, thus, having a Schilling-like reliever on the mound for an inning or two is likely to contribute a great deal to a team's win - perhaps more than a starter's average inning. On the other hand, Ligtenberg's Win Shares can be compared with that of other middle relievers, and Schilling's with that of other starters, to determine which pitcher excelled within their respective roles.

Finally, and perhaps fatally to the argument in the article, is that the sample suggested to study (pitchers who have pitched a significant number of innings as both starters and relievers over three seasons, are not young, are not old, and who have stayed with the same team for the entire duration) is very non-representative of the population of major league pitchers. Frankly, this suggests a study based on failed starters who managed to hang in the majors via bullpen success. Although Guy notes that this might introduce bias, I think he seriously underestimates the impact that such a non-representative sample will have on the data - most pitchers simply do not fit into this category and the ones who do very likely differ in important ways from those who don't.

In addition, this kind of study ignores the fact that a very large number of pitchers likely fit into their current roles "by accident." It is unclear how many relief pitchers would indeed be successful starters if they had an opportunity and had somehow maintained their readiness for that role. Likewise, it is unclear how many failed starters were not given a real chance to pitch out of the bullpen in any case (think Jim Parque). Finally, the entire sample Guy proposed would likely be so small as to call into question any results at all.

So what would be the best tactic to use to determine starters' and relievers' actual usefulness? I would favor the methods used by James and others who use regression analyses to determine the relative contributions of individual players to their teams' performance (i.e., wins, runs allowed, etc.). Although these methods may not necessarily determine which pitcher has more talent, they would determine which pitchers successfully helped their team reached the goal of winning games, regardless of their respective roles on the team. These methods also avoid the issues of sample size and sample bias that would sink a study like the one proposed here.

Valuing Starters and Relievers (December 27, 2003)

Posted 9:01 p.m., December 27, 2003 (#7) - kamatoa
  David -

ALP sounds like an interesting system (you're right - I can't say I've heard of it). Where could I learn more?

Valuing Starters and Relievers (December 27, 2003)

Posted 10:07 a.m., December 29, 2003 (#23) - kamatoa
  As others have mentioned, this is a very interesting discussion.

I think the most insurmountable problem in Guy's thesis is the sampling issue. However, I would definitely be willing to withhold judgment until seeing the results. If Tango is right when he says that there is no difference in performance based on times through the order, then it would be reasonable to suppose that any difference in the ERAs between starting and relieving in even this highly selective group of spot-starters, swingmen, demoted starters, and stretched-out relievers could be due to the relative ease of pitching from the bullpen. (Although it has just occurred to me that this relative ease of bullpen pitching might be partly due to managerial strategies that enable favorable pitcher-batter matchups - perhaps LaRussa has it right, strategerie could make a difference.)

Tango was somewhat critical of my contention that a single run has the same weight in a game regardless of who gave it up. Although I acknowledge the greater sabermetric expertise of others on the thread, I would simply reassert my belief that pitcher evaluation systems currently in use already measure the relative ease of bullpen pitching (the relative ease of which Guy convincingly argues), since bullpen pitchers receive higher per-inning evaluation scores than starters, despite these pitchers' relatively lesser talent. The marginal per-inning win share for a reliever over a starter probably represents the relative ease of starting, to a significant degree.

A couple of 2003 cases can serve to illustrate (chosen because of their similarity in ERA):

Eddie Guardado: 65.3 IP; 2.89 ERA; 3-5; 41 SV; 15 Win Shares
Esteban Loaiza: 226.3 IP; 2.90 ERA; 21-9; 0 SV; 23 Win Shares

Both pitchers pitched well for their teams and contributed to team wins. Both were rightly considered among the best at their respective roles in 2003. However, Guardado's per-inning win share was .22 (almost exactly the same as Eckersley's MVP year of 1992), whereas Loaiza's Cy Young-contending per-inning win share was .10. Although Loaiza's success in 2003 may or may not have been a fluke (mastering a new "out pitch" may have greatly helped Loiza in 2003), few would suggest that Guardado was more than twice as talented as Loaiza in 2003, inning for inning, especially given their similar ERAs. Since the discrepancy between Loaiza's and Guardado's scores are not likely due to their respective talent in 2003, it is probably somewhat due to the differential difficulty in pitching as a starter vs. a reliever - since making outs as a reliever is "easier," then relievers progress teams more quickly toward wins, on an inning-for-inning basis, and thus earn more win shares due to their role alone.

For a more modest example, take these two pitchers' 2003 stats:
Tim Spooneybarger: 42 IP; 4.07 ERA; 1-2; 0 SV; 3 WS
Adam Eaton: 183 IP; 4.08 ERA; 9-12; 0 SV; 7 WS

Spooneybarger's .071 per inning win share is nearly double Eaton's .038 per inning rate, a difference not likely due to talent. Although Eaton is rightly acknowledged to have contributed more to his team's wins overall, Spooneybarger has the appearance of having contributed more than Eaton in any single given inning, despite their similar ERAs.

Although I know these examples are crude (they do not control for overall team performance and other variables that introduce variance into the win share system), but I think they suitably illustrate that systems like win shares already acknowledge the relative ease of relieving by inflating relievers' per-inning scores relative to starters who post the same ERAs over more innings.

Guy wrote: I think the reliever advantage, if it exists, clearly does have important ramifications for many player valuation systems. I agree with this statement, but comparing relievers and starters on one of these systems, Win Shares, suggests that the system may already acknowledge the benefit relievers receive from their role, regardless of their talent compared to starters.