from Amazon
Friday, July 09, 2010
Do you want to bet Rob Neyer?
He says:
Maybe you still don’t believe in luck. That’s fine. I have my belief system, and you have yours. But I can tell you, with metaphysical certitude, that if you bet on pitchers with sub-.280 BABiPs allowed to do it again next year, you’ll lose almost every time. Because almost anything lower than .280 (or higher than .320) can easily be dismissed when discussing a pitcher’s skills.
By my count, since 1996, with at least 400 balls in play in both seasons, the sub-.280 happened 286 times in year 1, and stayed at sub-.280 in year 2 86 times. That’s a 30% chance of winning money from Rob. 107 times did a pitcher post a .320+ BABIP, and 25 times he did it again. That’s a 23% chance of winning money from Rob. If I drop the requirement to at least 200 balls in play, you win 57 of 274 times (20%) on the .320+ bet, and 208 of 606 (34%) on the .280- bet.
UPDATE: what is the breakeven point? There were 979 pitchers with sub .291 BABIP in year 1, and 490 of them repeated it. That’s 50%. On the flip-side, there were 814 pitchers with a .299+ BABIP in year 1, and 408 repeated it in year 2. That’s 50%. As you can see, the breakeven point is pretty much close to the league average.