Over a winter that saw them essentially fire a Hall of Fame manager and sign their third baseman to the richest contract in baseball history, the most important thing the Yankees did was, unlike these other moves, infinitely uncharacteristic: They committed to Phil Hughes, 21, Joba Chamberlain, 22, and Ian Kennedy, 23. Having found the religion of young pitching, Yankeeland has bet the success of the entire season on three pitchers who between them have 16 major league starts. New converts are always the most fervent. However much this recalls the Mets’ ill-fated reliance on Generation K, it may not be as risky as it seems. The Yankees will play 162 ball games this year. If you cautiously assume that Chien-Ming Wang and Andy Pettitte will each start 30 of them, and that Mike Mussina will start another 25, this leaves 77 games. Divide this workload among Hughes, Chamberlain, and Kennedy, and assume that each will average six innings per start, and it comes to 26 starts and 156 innings apiece. Divide it among these three and Kei Igawa, and it comes to 19 starts and 116 innings apiece.

On the lower end, these are reasonable expectations. Last year, between the majors and the minors, Hughes pitched 116.3 innings, Chamberlain 116, and Kennedy 165.7. Going by the rule of thumb that a young pitcher’s innings should never increase by more than 30 from the one year to the next, each of the greenhorns should be able to handle 116 innings and still have gas in the tank for October. So long as Wang, Pettitte, and Mussina take their turns, and so long as Igawa or similar pitchers take theirs, the Yankees won’t be asking too much.

On the higher end, though, the team may have a problem. Let’s say Hughes and Chamberlain each pitch 156 innings in the regular season and then make three starts in October. For each, this would represent an increase of about 60 innings. It likely wouldn’t put them at any risk of immediate injury (though perhaps it would, given their sketchy medical histories), but as Sports Illustrated’s Tom Verducci has documented over the years, increases this large put pitchers at meaningful risk of abrupt decline.

This is partly a selection effect, as any young pitcher given a large major league workload is likely to be very good and thus likely to regress the next year. Mostly, though, it’s a reflection of how physically demanding pitching is and of how long it takes for a young pitcher to build up the stamina to handle a role at the front of a rotation.

The Yankees could probably get away with riding their three young starters as hard as the Chicago Cubs rode Kerry Wood, Mark Prior, and Carlos Zambrano in 2003, when those three averaged 235 innings apiece, including the playoffs. But then they’d probably end up like the Cubs, with one ace, one reliever, several ruined seasons, and a lot of bitter fans. Trading the future for the present doesn’t work, even when it wins you a pennant.

An awareness of this is what inspired last year’s famous Joba rules and what led the Boston Red Sox to shut down 23-year-old Clay Buchholz (who, frighteningly enough, may be better than Chamberlain and Hughes) last fall even after he threw a no-hitter in his second start. Like the Red Sox, the Yankees are to be congratulated for demonstrating that, unlike the Cubs, they have bare common sense and an idea of what the word “restraint” means. Now, though, they have to keep it up.

Hypothesizing that if everything goes well the team won’t be put in a position where it has to ask more of Hughes and Chamberlain than it should is one thing, but everything does not always go well. Last year, Tyler Clippard, Matt DeSalvo, and Darrell Rasner started a half-dozen games apiece for a $200 million team that spent the summer in a frantic pennant race. If Mussina hits a spell where his fastball won’t break much past 80 and Pettitte’s elbow and effectiveness goes the way of his credibility as a trustworthy friend, the team will be faced with a concrete choice between pushing their studs toward innings levels they shouldn’t reach and giving the ball to pitchers like Clippard.

The choice is clear. Even if it means deliberately giving away the pennant, the Yankees have to protect the futures of their young pitchers. It’s the most important organizational priority, an essential commitment they made by not trading Hughes and Kennedy for Johan Santana. What we don’t and can’t know, no matter how many protestations are made to the contrary, is whether the team has, at every level from ownership down to the dugout, fully appreciated the main implication of this, which is that the storied Yankees may have to give something less than their best effort.

tmarchman@nysun.com