At the time that lewis was writing, the A's had just won 101 and 102 games in two successive seasons.

Since then it has been 95, 91 and 88. lots of reasons for the decline, but I don't think anyone doubts that Beane and Co.s job has grown tougher as more teams catch on. the red Sox won a WS by shifting to a more Moneyball-oriented approach; Beane himself has signalled the change by abandoning the pursuit of high OBP players in favor of defense, and changing his pitching draft strategy to high schoolers.

Beane is still chasing the market inefficiencies, and doing it well-- but it stands to reason that he has a much smaller margin of error given the increased competition.

One thing you have to keep in mind is that Moneyball is a book for a General Manager, not a field Manager, who takes each game one at a time.

The GM looks at the whole season, and tries to put the best team together who will, over the course of 162 games, win 10% more games than the average team.

Keep in mind, baseball is a game of small advantages, which lead to slight differences in overall outcome.

What Billy Beane did was figure out how to make his limited budget go farther.  You sort of pooh-pooh that, but that's what he did, and what lots of people don't.

Its why he realized that he didn't need Five Tools guys, because not all tools were equal.  Its why, during the time of the book, he focused on OBP and college players -- because baseball wasn't paying full value for them, so he got bargains.

Last off-season, by contrast, he saw that baseball was routinely paying too much for starting pitching, so dealt Hudson AND Muldur -- classic Moneyball move: take what the market will give you.

And, in the draft, since the pendulum had swung so much in three years towards college players, he saw an opportunity in undervalued high school kids.  

I suspect he is still seeing value in a couple of other areas, some of which aren't even measured.  I think there's huge benefits from what I'd call balls in play, the number of batted balls that go fair, comapred with plate appearances.  I think Billy has focused on guys who, when they don't walk or get base hits, help the offense by not striking out, putting the ball in play during rallies (preferably on the ground, so players can move up) and who do not give away outs.

"the A's are screwed once every team starts doing the same thing, because then they will back to square one"

thank God not too many teams are buying into what we do, and prolly never will

there are a lot more GM's who still think it makes sense to overpay some guy who strikes out 150 times a year than it is to measure a players real effectiveness.  Even at AN we are constantly bombarded by the silly notion that some over the hill guy who hits 30 HR's will make all the difference in the world to the A's, he won't.