In the 1921 season, Meusel started in 149 out of 154 games, primarily playing right field. He batted .318, finishing second in the league in home runs with 24 and third in the league with 136 runs batted in. He hit for the cycle in a win against the Washington Senators on May 7. In the second game of a September 5 doubleheader, he tied a major league record for outfielders (previously accomplished by nine others) by recording four assists. He broke a club record and tied Jack Tobin of the St. Louis Browns for the league lead in outfield assists with 28; he was considered to be one of the league's best all-around players. Meusel's brother, Irish, was acquired by the New York Giants from the Philadelphia Phillies mid-season, and helped lead the Giants to the pennant. The two brothers played against each other in the 1921 World Series, where the Giants faced their tenants (the Yankees played their home games in the Polo Grounds, the ball park owned by the Giants). Bob Meusel stole home in Game 3 of the Series. He doubled in Babe Ruth for the winning run in Game 5 for a one-game lead, but the Yankees lost the next three games and the Series (the last best-of-nine in World Series history). His batting average in those eight games was a mere .200.