the only 2 differencea iare that the yankees have been able to absorb the horrible signings and get just a little bit more out of who they get than the sox did. AND, the yankees hang onto their players for the most part (Pettitte not withstanding). There are certain parts of your team that you cannot merc out, and for the yankees, it was Jeter, Posada and Rivera. For the sox, that was Petey and Damon, and it was obviously a factor these last 2 yrs (1 for Damon).
Another minor difference, is that for all the fanfare the sox minor league system has gotten over the yankees for the past few yrs, the yankees sure have produced more of their own talent. Proctor, Cano, and Wang to name a few were recent callups from within their system (proctor was traded for when he was still a minor leaguer). While the sox just have Papelbon and a few maybes right now.