The narrative, from game to game and season to season, is definitely part of it. To toss another reason in there, I know I'm also into it for the sense of comraderie. As a Mets fan, I feel a sense of kinship for all other Mets fans, no matter how different we might be (I feel the same way about other anime fans. ;) ). There's nothing quite like the rush of being in a stadium with 40,000 other people who feel just like you do, and seeing things go great - or the commiseration when they go terribly...