When Dave Roberts was being tutored by Maury Wills on the finer points of base-stealing, a passion the two shared in Los Angeles for 21/2 years, there was one thing the Los Angeles Dodger instructor and former all-star often said that stuck in Roberts's mind.

"Maury told me that anyone can do the safe thing," said Roberts, who played outfield for the Dodgers from 2002 until the July trade to the Boston Red Sox, "but it takes someone special to take a chance."

Consider Roberts special.

David Ortiz was named the American League Championship Series' most valuable player after hitting .387 with three home runs and 11 RBI against the New York Yankees. Johnny Damon had two homers and six RBI in Boston's decisive Game 7 victory Wednesday night, pitchers Curt Schilling and Derek Lowe provided several gutsy starts, and an overtaxed Red Sox bullpen came through when it was needed most.

But the Red Sox would not be hosting the first two games of the World Series this weekend if not for Roberts, whose stolen base in Game 4 was the pivotal play of the AL Championship Series.

Trailing the best-of-seven series three games to none, trailing the Yankees, 4-3, in the bottom of the ninth Sunday, facing baseball's most dominant October closer, Mariano Rivera, with the Yankees three outs from a series sweep, Roberts replaced Kevin Millar after the first baseman drew a leadoff walk in the ninth.

Roberts stole 38 bases in 41 attempts this season, a 92.7 percent success rate that was second only to Carlos Beltran (93.3) in the major leagues, and Rivera, mindful of Roberts's speed, threw over to first base three times before delivering a pitch to Bill Mueller.

But Rivera, as Roberts said, "is not used to having guys on base," and the right-hander did not shorten his leg kick on his first pitch to Mueller. Roberts, who did not play in the first three games of the series, broke for second with a burst of speed, sliding head-first just in front of catcher Jorge Posada's throw for a stolen base.

Mueller squared to bunt the next pitch but pulled back, taking a strike. After Manager Terry Francona took off the bunt, Mueller singled to center to score Roberts with the tying run, the Red Sox went on to win, 6-4, in 12 innings, and Boston went on to become the first team in baseball history to erase a 3-0 deficit and win a seven-game series.

"I think the biggest play of the series was Dave Roberts's stolen base in Game 4," Lowe said after winning Game 7 Wednesday night. "It gave us an opportunity to get to Rivera, and you know, you always say you think you have a chance, but realistically, maybe in the back of your mind you don't know. But we just kept winning, and we wanted to try to get to the next day, and we kept doing that."

Roberts also played a key role in Boston's Game 5 comeback. After Ortiz hit a home run off reliever Tom Gordon to open the eighth inning, pulling the Red Sox within 4-3, Millar drew another walk and was replaced by Roberts.

This time, Roberts didn't steal second, but he appeared to distract Gordon enough to where the Yankee setup man fell behind Trot Nixon, who lined a 3-and-1 pitch to center to advance Roberts to third. Jason Varitek's sacrifice fly off Rivera tied the score, 4-4. The Red Sox went on to win, 5-4, on Ortiz's run-scoring single in the 14th.

"It's not just about stealing a base," Roberts said. "It's about putting the team in a better position to score, making the pitcher throw more fastballs."

Roberts's speed and left-handed bat and Marquis Grissom's power from the right side formed an effective center field platoon for the Dodgers in 2002, with Roberts enjoying his most productive year in the big leagues, batting .277 with 63 runs and 45 stolen bases.

Leg injuries hampered Roberts in 2003, when he batted .250 with 56 runs and 40 stolen bases, and with 2004 deals for Milton Bradley before the season and Steve Finley at the July 31 trading deadline, Roberts became expendable in Los Angeles.

Boston General Manager Theo Epstein, believing Roberts would make a nice spare part on a team with World Series aspirations, swung a deadline deal for Roberts with Dodger GM Paul DePodesta, and all it cost the Red Sox was marginal outfield prospect Henri Stanley.

Roberts, 32, batted .256 and scored 19 runs in 45 games for Boston and, combined with bench players such as first baseman Doug Mientkiewicz and outfielder Gabe Kapler, gave Boston a key edge over New York in the AL championship series.

While the Yankees bench featured one-dimensional players such as first baseman Tony Clark, outfielder Bubba Crosby and infielder Enrique Wilson and had little impact on the series, Roberts and Mientkiewicz, who made a superb backhand scoop of Mueller's throw to retire Derek Jeter on an eighth-inning groundout Wednesday night, made significant contributions.

"Dave Roberts has been unbelievable," Francona said Thursday in Fenway Park. "He deserves to play more than he does. He understands the situation, and the same thing with Mientkiewicz. They have been very professional, above and beyond their call of duty in their attitudes. We're here to win and your egos and personal things get thrown aside if you're doing it right, and they have done it right.

"But they also contribute. Mientkiewicz made that play [Wednesday]. Dave Roberts stealing a base in the ninth inning [in Game 4]. To me that was as big a play in the series as any. I marvel at the fact that he can do that. Not only do they sit with good attitudes, but they're weapons for our team to win games."

Neither player is thrilled about his backup role -- both are in their prime and want to play every day -- but reaching the World Series makes it worth it.

"It doesn't get any better than this," Roberts said. "I wish every player could experience this."

While most kids dream of hitting the game-winning home run in the last inning of the World Series, Roberts, the 5-foot-10, 180-pound speedster, has a different vision.

"I dream of being on first base in the bottom of the ninth, being down by a run," Roberts said, "and everyone in the stadium knowing I'm going."

David Ortiz batted .387 with three home runs and 11 RBI in earning the ALCS MVP award. Ortiz, Boston's designated hitter, will be asked to play first base in St. Louis. Woody Williams will start Game 1 for St. Louis against Boston knuckleballer Tim Wakefield. Williams went 11-8 for the Cardinals, who won a major league-best 105 games. After a less than dominating ALCS, Pedro Martinez will start Game 3 on Tuesday for the Red Sox in Busch Stadium. Martinez was 16-9 with 3.90 ERA during the regular season. Albert Pujols slugged 46 home runs and batted .331 during the regular season and was even better during the NLCS, where he was named MVP with 4 home runs, 11 RBI.