Arizona beats the odds
Interesting article from some site called the Hardball Times (link via the Wall Street Journal website's "Daily Fix" column) positing a rational explanation for why this year's Arizona Diamondbacks are (at this writing) 71-56 despite baseball's version of the Pythagorean theorem saying they should be eleven games worse, 60-67, given that their opponents have outscored them 575 to 543. (Last year, Cleveland, unfortunately, deviated from the Pythagorean theorem in the opposite direction.) The explanation (basically, the D-Backs have great closers, but terrible middle relief) sounds reasonable to me, although it would seem sheer random variation can't be ruled out. The P-theorem in baseball is not perfect. For instance, the very best and very worst teams' P-wins usually under- and overstate, respectively, their actual wins: The P-theorem says that the 1954 Indians should have gone 104-50, but they actually went 111-43, while the '62 Mets were 10 games worse than their predicted record of 50-110.
Has the concept of the baseball Pythagorean theorem entered the mainstream? The article reminded me that I heard it mentioned on a Reds TV broadcast a week or so ago, in the same context as the article -- the incongruity of the D-Backs' won-lost record this year. The Reds weren't playing the Diamondbacks at the time, but the announcers mentioned the final score of that night's D-Backs game, at which point lead announcer Thom Don't Call Me Tom Brenneman commented on how odd Arizona's success was because "generally your won-lost record is determined by the margin by which you outscore your opponents" (as I recall), to which his sidekick responded (again, as best as I can recall) "yep, the Pythagorean theorem." I almost fell off the couch; baseball aficionados have known about the P-theorem for a long time, but it was shocking to hear members of the media acknowledge it.
