But as the ancient diamond rivals meet this weekend - and maybe again next month in the American League Championship Series - an impressive group of young players has emerged as difference-makers for both clubs.
The Yankees have pitchers Phil Hughes, 21, Ian Kennedy, 22, and Joba Chamberlain, 21, playing important roles. They've joined Robinson Cano, 24, Melky Cabrera, 23, and Chien-Ming Wang, 27, young talents who have blossomed in pinstripes the last few seasons.
The Red Sox built their bullpen around 26-year-old Jonathan Papelbon last year and have continued to get strong performances from youngsters Clay Buchholz, 23, Jon Lester, 23, Jacoby Ellsbury, 24, and Dustin Pedroia, 24, this season.
Buchholz has been in the majors for a month and already has three wins, including a no-hitter. Lester, who a year ago was beginning treatment for non-Hodgkin's lymphoma, a blood cancer, is 4-0. Pedroia entered Friday hitting .327, seventh-best in the AL, and is a leading candidate to win rookie of the year.
In the Yankees' bullpen, power-armed Chamberlain had allowed just one run (unearned) in his first 12 appearances. Kennedy has turned in three quality starts since coming up from triple A, Hughes has shown flashes of what has made him a top prospect, and Wang has 18 wins.
Once upon a time, Chamberlain, Kennedy, Hughes and Wang might have been trade bait for the Yankees, especially in a season like this. (They were eight games under .500 on May 29, looking like they were on a road to nowhere.)
