I thought is was great. It's a cute kind of romantic comedy by description. I don't know how it would be for someone who doesn't like baseball, but for a baseball fan, it's terrific. I'm a Giants fan first, but 2nd I'm a baseball fan, so I want what's best for baseball. That's what I told myself when the Giants lost to the Angels in 2002 for their first title. Yankee fans probably won't like the movie though. It was cool how they have live footage during the game with Jimmy Fallon and Drew Barrymore.
It was originally a book about a soccer team. The movie was supposed to end with the Sox losing (as usual), but when the magic happened they had to re-work the ending.