 Based on the 2003 nonfiction book of the same name by Michael Lewis, the film focuses on the 2002 season of the Oakland Athletics baseball team.The team's general manager Billy Beane (Pitt), and assistant general manager Peter Brand (Hill), decide to build the team by opting for a sabermetric approach to selecting players.The screenplay was written by Aaron Sorkin and Steven Zaillian, while Stan Chervin wrote the story.