Factual error: When Beane takes his daughter to look at guitars, she plays and sings Lenka's "The Show", a single which wasn't released until 2009, despite the movie taking place in 2002-2003. (00:42:45 - 00:44:10)
Factual error: In the crowd at one of the games where Brad Pitt (Billy Beane) shows up to the game, there is a kid with a camera phone taking a picture of him. Camera phones weren't available in the US until after the time frame of this movie.
Factual error: When Billy Beane is listening to Game 5 of the 2001 ALDS on his portable radio, we should either be hearing the Athletics radio announcers or ESPN Radio's coverage. Instead, we keep hearing the voice of Thom Brennaman, who was calling the game on television for the Fox network.
Factual error: Jeremy Giambi and Carlos Peña were not traded on the same day. Giambi was traded on May 22nd and Peña was traded on July 5th.
Factual error: Game 5 of the 2002 ALDS between the A's and Minnesota Twins wasn't a night game, as depicted in the film. The game started in Oakland at 1:00pm. (01:51:15)
Factual error: Scott Hatteberg shouldn't have had to realize he could increase his chances of getting on base by taking more pitches and getting walks; in real life, he was always willing to take called strikes instead of swinging at pitches he knew he couldn't make contact with. That ability to take a lot of pitches and get on base was the primary reason Billy Beane was so eager to sign him in the first place.
Factual error: Boston Redsox stadium did not look like that when Billy visited it in the movie. Fenway Park has gone through multiple renovations since then. The most obvious errors included the concessions section he enters Fenway through was newly renovated since '02, the first shot of Fenway includes the '04 & '07 banners, and a later shot included the wall with the monster seats, which did not yet exist.
Factual error: In the scene where Billy (Brad Pitt) comes to talk to Scott Hatteberg about joining the A's, Scott wears Nike+ shoes, although Nike+Ipod was only introduced in 2006, whereas the film takes place around 2003.
Factual error: Throughout the film, it's implied that Scott Hatteberg was a poor fielder at first base. He actually ended the 2002 season with a fielding percentage higher than the league average for his position.
Factual error: When he's shown as a Twin in 1986, the Cleveland Indians' catcher is wearing the uniform from 1992 with the memorial patch for Steve Olin and Tim Crews who both died tragically during Spring Training of '92 in a boating accident. (00:46:25)
Factual error: In the flashback of Billy Beane at Dodger Stadium, the ballpark looks as it does in the 21st century, not as it did in the mid 1980s. Most noticeable is the dugout fence, which did not exist until after the 2004 season.
Factual error: The final out in game 5 of the the ALDS against the Twins, the movie focuses on third baseman Corey Koskie catching the final popout. In the actual game, the ball was hit over by the A's bullpen where the second baseman Denny Hocking sprints over to make the catch.
Factual error: The NBA arena adjacent to the Oakland ballpark has the Oracle label on the exterior. At the time, the venue was simply known as The Arena in Oakland. Oracle purchased the naming rights in 2006.