Billy Beane is the general manager of the Oakland Athletics baseball team, famous because his revolutionary approach to assessing talent and creating a professional sports team. It's not often a book - and then an Oscar-nominated movie - are written about a sports executive.
Beane studies lots and lots of statistics in assessing talent, creating unique calculations of value in a process called sabermetrics. So, whereas another general manager would have seen great value in a strapping young prospect with a batting average of .350 (hits/at bats), Billy Beane might find the prospect's actual value to be far less looking at his (hits +walks) (total bases)/(at-bats + walks).
Bored yet? Lots of old-school managers were, too. Until Billy started winning. And winning. And winning with a pretty small payroll. A million here, a million there, and pretty soon you'll catch people's attention.