Just pulled this while perusing some Yankees' stats:
Alex Rodriguez would lead baseball in home runs if he only hit against right-handed pitchers. You could throw out his 101 AB against lefties, and he'd lead Prince Fielder by one. A-Rod has 31 HR in 288 AB against righties, 4 HR in 101 AB against lefties.
He's third on his own team in homers against lefties -- both Matsui (7) and Posada (5) have more.
Jeter has one HR against lefties. His power numbers are usually about the same against lefties and righties, with a better average against lefties.