During a visit to another club he notices that the general manager over at the other club listens to a particular person before deciding on which players to recruit. Billy doesn't quite understand why just yet, but senses that this is the "something different" he was looking for. Billy then proceeds to include this new person in his latest player swap.
The onetime player Billy is now teamed up with Ivy League graduate Peter Brand (Jonah Hill) whom has a mathematics degree, not baseball. Statistics and probability is something that hasn't really been used before to determine which players to recruit. The scouts have always gone on gut and instinct.
Thus forms an unlikely partnership, recruiting bargain players that the scouts call flawed, but all of whom have an ability to get on base, score runs, and win games, according to the maths. It's more than baseball, it's a revolution - one that challenges old school traditions and puts Billy in the cross-hairs of those who say he's tearing out the heart and soul of the game.
Just like any major change the results don't appear straight away, the coach isn't on board, the fans aren't on board, the commentators go on about how baseball isn't maths, and statistics can't be applied as "heart" is a factor. In the end (this is a Hollywood movie) Billy's approach starts to pay off big.