Leading lefties

Jon Lester's performance has been a boon to the Sox this year. He's won eight of his last nine starts (8-3, 3.20 overall) and has pitched 7 innings or more in all but two of them. Andy Pettitte's 11 wins are fourth-best in the AL, and he (along with the seemingly ageless Mike Mussina) has anchored a Yankees staff beset by injuries and ineffectiveness.