All fair and valid points.tangotiger wrote:I once posted the leaders/trailers in WPA for the 1999-2002 time period. (I'll see if I can find it in a sec.)
Anyway, what I did with pitchers was two ways:
1. count all balls in play as 100% responsibility of the pitcher
2. count all balls in play as ZERO% the responsibility of the pitcher
And, guess what? With 4 years of data, the results were virtually the same.
From the pitcher's perspective then, whether I'm able to figure out how to properly assign responsibility for a ball hit in the gap (presuming I have hit location data), it becomes not worth it, in the aggregate sense.
Of course, it matters on a game basis. For example, in that Cubs meltdown in 2003, most of those balls were hardhit, and it didn't matter who the fielders were (except for that SS error). But, we know that, because we all saw that game. If all we have left is a game account of it, we wouldn't be able to really know that, and we'd have to rely on hit location and other things to infer responsibility.
As to the fielder, we never really think of his "game saving" plays, but rather just the play itself, irrespective of the game situation.
For this reason, I prefer, for simplicity's sake, to give 100% responsibility to the pitcher, and stick with UZR for fielders.
I was mostly just wondering how much wading into those waters has been done. The only thing that partially bothers me is that errors count as a demerit for a pitcher, who should have gotten something positive out of the play. And they go as a positive for the batter, correct? But I guess everything evens out--hitters get robbed by great plays too that possibly shouldn't have been made.
--P--
