Saturday, October 13, 2007

Sports Guy gets his stathead on

In response to a reader question about teams moving to a short rotation in the baseball playoffs, Bill Simmons writes,

SG: Graham, that's a fantastic question. I don't have an answer for you. The three-day rest thing only seems to work when you don't have another choice (like the Red Sox in 2004, for example). If it's a conscious decision, the results always seem to be brutal. But I have another question: Why is everyone always so confident that sinkerballers are better on three days rest? People just spout this out like it's a foregone conclusion -- oh, yeah, it's fine when Wang pitches on three days rest, he's a sinkerballer. It is? Who said? Do we have scientific proof that it's better for any pitcher (even someone with a specialty pitch like the sinkerball) to be more tired than less tired? I'm dying for them to tackle this on "MythBusters."

That's a great response from Simmons; I want only to add that this case offers an excellent demonstration of the power of the optical revolution in baseball analysis. We suddenly have the power to know exactly what happens to sinkerballers after three or four days of rest, to see whether any effect correlates with the amount of sink on pitches, and to do all of this with a direct measurement of the pitches' break instead of inferring that measurement from fly ball/ground ball ratios. Amazing.