I just look at their roster and yes, they have some talent, but guys like Nava, Carp, Steven Drew, Iglesias, Saltalamacjkaia, Napoli, Gomes, David Ross, Middlebrooks, whoever the hell also played 3rd for them when Middlebrooks wasn't playing well, etc etc. Felix Dubront, Koji retiring 395 straight batters etc etc
I mean, a lot of these guys are has-beens or never-weres (this guy's dead! Cross him off the list!) and they came together and just rolled.
Now they may lose Ellsbury and I really really think they're gonna get hit hard by the regression monster. Or maybe these guys are all awesome.