While many of us eagerly await the May arrival of Will Carroll’s “The Juice” in finer bookstores, “Moneyball” author Michael Lewis shines some light on the subject and its impact on player development in tomorrow’s New York Times Magazine section.

Another piece of evidence that steroids work is the reluctance of the players to part with their drugs. A few weeks ago, not long after after Major League Baseball’s public humiliation before Congress, the commissioner’s office released the names of 41 minor-league players who failed spring-training drug tests. The players came from just 10 of the 13 major-league organizations tested so far. Given the public outrage over steroid use during the off-season, you might think that the minor leaguers would have arrived in camp prepared. (They needn’t stop taking steroids altogether; to avoid being caught they only had to stop taking them a few weeks before the test.) And yet an average of more than three players per organization appeared to be unwilling to play clean.

Perhaps all this means nothing. Perhaps minor leaguers are deluded about the importance of the drugs. On the other hand, they might be right that they need them — that steroids are so helpful in today’s game that a 15-game suspension and a reputation as a steroid user is a small price to pay for the benefits. The evidence is unlikely ever to be anything but inconclusive. There are too many alternative explanations for the power surge: players have altered their swings (though most swings are still idiosyncratically personal affairs); players have grown naturally stronger (but have they?); some hitters, like Barry Bonds, have switched from ash to maple bats (though most hitters haven’t); pitchers aren’t as good (though there is no hard evidence of this); ballparks are smaller (though a few are actually bigger).

But the ambiguity of steroids’ effects may have, in an odd way, increased their grip on the game. Unable to parse the statistics and separate natural power from steroid power, the people who evaluate baseball players for a living have no choice but to ignore the distinction. They’ve come to view the increase in the number of young players without power who become older players with power as a new eternal truth about the game. ”Good hitters become power hitters, power hitters don’t become good hitters” has become a kind of cliche for baseball’s more statistically minded general managers. Power is now understood as less an innate gift than a gettable skill — more like speaking French than being 6-foot-3. Which is to say that steroids may have changed not only the way the game is played but also the way the game is understood. They have given birth to a big, beefy idea from whose side-effects no player is immune.