Comments on: Pitcher Win Values Explained: Part Four

By: Colin Wyers

Colin Wyers — Thu, 15 Jan 2009 17:19:23 +0000

I’m starting to come around to the idea that the split shouldn’t be even – that a replacement-level team is worse on offense than defense, typically. We know, after all, that our typical replacement-level hitters are also typically average defensively.

By: TangoTiger

TangoTiger — Thu, 15 Jan 2009 15:23:50 +0000

That’s a fair enough point, and easy enough to test.

By: MattS

MattS — Thu, 15 Jan 2009 04:44:10 +0000

This is a little bit nit-picky, but it’s not really proper to divide by .92 for every one. Unearned runs occur less frequently for strikeout pitchers and flyball pitchers, because balls in play are more likely to be botched than strikeouts and groundballs are especially likely to be botched. I would think it’s best to re-devise coefficients based on a regression of RA on K/9 BB/9 and HR/9, and then do the adjustments you’ve done to that FIP.

The goal here is a proper ordering of players. While these effects may be small, you want a consistent estimator that properly orders players by their effects on run prevention.

By: Dave Cameron

Dave Cameron — Wed, 14 Jan 2009 18:39:25 +0000

Historical, empirical evidence gives us a .300 win% for a team of replacement level players. To win 30% of your games, however, does not mean that you have a .300 win% run scoring and .300 win% run prevention. Because of the multiplicative effect, a perfectly balanced team of replacement level players would have a .395 offense and a .395 defense. Run prevention is divided up between starters, relievers, and defenders, based on their retrospective amount of responsibility. The results of slicing .395 those three ways is .380 for starters and .470 for relievers. Read this and this for more data.

By: azruavatar

azruavatar — Wed, 14 Jan 2009 18:16:03 +0000

There’s still little explanation as to how the 38% is actually derived. A link to an old tango post in which he says he sets it at 38% but no indication as to how the result was really arrived at.

By: Dave Cameron

Dave Cameron — Wed, 14 Jan 2009 18:01:01 +0000

Parks actually do have an impact on walks and strikeouts. Dave Studeman covered this in the Hardball Times Annual a few years back.

And, that’s actually somewhat besides the point. Regardless of what factors the park actually impacts, the win value of a run changes with the environment. In a park where you only have to score three runs to win, a 5.00 FIP is much less valuable than it is in a park where you have to score six runs to win.

If we were projecting future performance, component park factors would be necessary. For retrospective valuation, it isn’t.

By: Dave Cameron

Dave Cameron — Wed, 14 Jan 2009 17:58:24 +0000

Saying he’s not Johan Santana is ragging?

By: Torx

Torx — Wed, 14 Jan 2009 17:29:07 +0000

With regards to the wonderful work you have all done here (with which I will waste many, many hours), I’d like a clarification.

If a ballpark suppresses or inflates offense by x%, why would you adjust the FIP by that same percentage?

If I understand FIP correctly, only one of the variables can be affected by park conditions. Does FIP scale appropriately with park conditions such that you can make this calculation? Or should you do something in the order of “since Safeco Field suppresses offense by x%, you adjust the FIP by x over y% since there are park conditions that do not factor into HR?”

Thanks again for the great work!

By: Jim C.

Jim C. — Wed, 14 Jan 2009 17:26:33 +0000

I’m tired of you constantly ragging on Cha Seung Baek.