You either pray to the gods for the Sox to win at least 8 of their last 10 games or temporarily root for teh Yanks. Seen as how the Sox can barely win these days, I'd say the ladder is your only choice.
Yankees can blatantly lose to the Rays and put them in the playoffs.
Not that the Yankees will lose to spite the Sox because that would be low even for them but Yankees hold the keys imo.