It's important these days for journalists to own up to their biases, so let me just say up front that I'm a card carrying member of Athletics Nation. I've been an A's fan since 1971, not counting a brief and shameful dalliance with the Giants in the late 1970s (when Charlie Finley let his team go to seed, and my parents had friends with a Candlestick luxury box).

The A's are of course more than just a baseball team. They are an economic phenomenon: A low-budget squad that has made the playoffs five of the last seven seasons (and come close the other two). After Michael Lewis provocatively chronicled the team's success at identifying undervalued talent in the bestseller Moneyball, they also became a controversial phenomenon, with baseball traditionalists splutteringly condemning A's general manager Billy Beane's obsession with statistics and even Freakonomist Steven Levitt wondering if maybe Beane wasn't just lucky.

An article in the summer 2006 Journal of Economic Perspectives by economists Jahn Hakes and Raymond Sauer (it's not available free online, but an earlier draft is) would seem to have put this debate to rest. Hakes and Sauer found strong empirical support for what they called the "Moneyball hypothesis"--that hitters' salaries "did not accurately reflect the contribution of various batting skills to winning games." (Essentially, batters who walked a lot were undervalued.) They also found that, after Moneyball came out in 2003, this labor-market inefficiency disappeared.

Which brings us to yesterday's playoff game between the A's and the Twins. That the A's made it to the playoffs yet again would seem to be testimony to GM Beane's skill, even though he no longer really follows the Moneyball formula (the A's payroll has ballooned all the way up to 21st among the 30 major league teams, and the team's success this year has had more to do with pitching and defense than the ability to get on base).

But the A's 3-2 win over the Twins in game one was about something else. Or someone else: Frank Thomas, whose two homers provided the margin of victory. In the past Beane has explained away the A's lack of postseason success with the excuse that short playoff series are a "crapshoot," not a real test of quality. This year he took a gamble on a gimpy former superstar whom no other team wanted. There's no way any statistical analysis could have told Beane that Thomas was likely to hit 39 homers and drive in 114 runs this season, then almost singlehandedly win the first game of the playoffs. It was a crapshoot, pure and simple, and yesterday it happened to pay off.

There are surely all sorts of important lessons about investing and business to be learned from this. But forget that: There's another A's game on this afternoon.

UPDATE: The crapshoot theme continued in game two, with the best defensive centerfielder in baseball betting that he could get to a line drive by the A's Mark Kotsay and turning out to be wrong. The resulting inside-the-park-homer provided the A's margin of victory.

Also, the Sports Economist blog, which counts among its contributors the abovementioned Raymond Sauer, has a couple of interesting recent posts on the "Moneyball hypothesis."