If you're a baseball fan this is a must see, and even if you're not this is the kind of movie that could turn you to be interested in the sport in the same way "Sideways" made people interested about wine.
The Oakland Athletics lost three great players in Jason Giambi, Johnny Damon and Jason Isringhausen to free agency. General Manager Billy Beane (Brad Pitt) can't get an increase in his payroll to sign big players. The scouts are all quite older than Beane, they are trying to replace those players using the same techniques that have failed before when valuing a player. Beane knows that firsthand. In a flashback, he was scouted by the New York Mets and touted as a five-tool player. These scouts say this is a once in a time opportunity and he has to go all out if he wants a shot in Major League Baseball. His parents seemed skeptical and want him to take his Stanford scholarship.
On a trip to Cleveland trying to find a replacement for Damon in a trade, he comes across Peter Brand (Jonah Hill), a man whose opinion is so valued by the Indians organization that Beane buys his contract. Brand convinces Beane that players are judged on superficial means and some are undervalued. He conceives compiling a team of misfit players on a budget by buying runs. They base their decision almost solely on on-base percentage.
This sends shockwaves to the scouts and to the manager Art Howe (Philip Seymour Hoffman). They sign a player who can no longer be a catcher named Scott Hatteberg (Chris Pratt) to be their new first baseman. They trade for David Justice (Stephen Bishop) for his high on-base percentage and the fact that the New York Yankees will pay half his salary just to get rid of him.
The season gets off to a rocky start starting off at 20-26, Beane starts getting upset with the way Howe is using his team. Howe is putting Carlos Pena in over Hatteberg. Beane retaliates by trading Pena away forcing Howe to put Hatteberg into the lineup.
The team improves over the season and they go on a 20-win streak before ending the season with more wins (103) than the previous season with those star players. Although the film makes it seem like it's due to these sabermetric ideas, the film never even mentions star shortstop Miguel Tejada and third baseman Eric Chavez, pitchers Barry Zito, Tim Hudson, Mark Mulder. If the season wasn't successful, this never would have been a movie.
It's still a great movie that does a great job making a movie about baseball, that isn't about baseball. It's about how you compete in a game that is almost rigged for the teams with more money. The film deduces that you always have a winner with money but then shreds that idea by presenting the story of the 2002 Oakland Athletics.
Would have rated it higher only for the twee song that his daughter sings, this seem harpooned in and went against the feel of the film. It destroyed my suspension of disbelief.