The Next To Win 20?

In every full season since 1983 at least one pitcher has become a 20-game winner for the first time, including Roy Oswalt, class of '04. Oswalt was 26 at the start of that season, which put him smack in the middle of the sweet spot for this group: Of the 62 pitchers to win 20 for the first time over this span of 21 full seasons (excluding strike-shortened 1994 and '95), 33 of them, or 53%, were between the ages of 23 and 29. With that in mind, here are the five aces most likely to join the 20-Win Club in 2006, in order of their potential (with 2005 record).

RICH HARDEN, 24, Athletics (10-5) The righthander missed 14 starts last year (muscle strains in his torso) and had off-season surgery on his left shoulder, but his throwing arm is fine. Harden was the AL's toughest pitcher to hit (.201 average) among those who threw 100 innings in 2005. He's 22-0 when he gets four runs, foreshadowing a breakout year with an improved offense behind him.

JAKE PEAVY, 24, Padres (13-7) He already has won National League ERA and strikeout titles and had two seasons with an ERA below 3.00. Though only 6 feet and 180 pounds, the righthander has excellent movement on his fastball and a killer changeup. Last season he averaged 4.32 strikeouts for every walk, the best such rate in the NL aside from Pedro Martinez's 4.43.

MARK BUEHRLE, 26, White Sox (16-8) With a career .616 winning percentage (85-53) and four seasons with between 16 and 19 wins, Buehrle has succeeded Mike Mussina of the Yankees as the best active pitcher never to have won 20. Scheduled to make his fifth Opening Day start, Buehrle has been remarkably durable: five straight seasons with at least 32 starts and 221 innings.

MARK PRIOR, 25, Cubs (11-7) In 2003, the one season the righthander stayed healthy, he won 18 games. Despite starting last year with an inflamed right elbow and then getting hit there by a line drive, Prior led the majors with 10.15 strikeouts per nine innings. A prototypical ace because of his size (6'5", 230) and power stuff, Prior has a career winning percentage of .641 (41-23).

JOSH BECKETT, 25, Red Sox (15-8) This righty is Prior's doppelg�nger, similar in size (6'5", 220), age (four months older), career record (41-34 with 4 1/3 fewer innings), draft position (both were No. 2 picks) and frailty. Beckett won a career-high 15 games last year with the Marlins despite a left oblique strain, recurring blisters and late-season shoulder stiffness.