During Pat Murray's last at-bat, his batting helmet changes between when he asks Maz for advice and when he walks to the plate.
At the 34-minute mark, Fotch tells Maz that a players get drafted from independent leagues every year. Players that fail to get drafted and play independent leagues have in fact used up their draft eligibility and are free to be signed as free agents. MLB teams do not draft players from independent leagues.
When Ty and Vinnie are in the back seat of the police cruiser and ask the officer to adjust the mirror so that they can watch the game, they both tell the officer to stop adjusting the mirror at the same time, i.e. the mirror in the one position. However, Ty and Vinnie should have a different perspective not being seated in exactly the same position relative to the mirror.
In the final inning, Maz says that Palaco is batting after Murray, at #8 in the order, with David hitting ninth, Garvey's spot, and then back to Maz at the top of the order. But after the fight, Palaco replaced Ty at third, and would bat at his spot in the order, 3rd. Barone, the DH, would enter the game at catcher, but still hit in his same spot, 2nd. David, who replaced Vinnie in right field, would hit at Vinnie's #8 spot in the order. And since Barone, the DH, has now entered the game as a position player, Dels the pitcher would now have to hit, in Garvey's #9 spot.
The character John Mazetti, played by Aaron Tviet, is incorrectly referred to John Mazzello. During the roster line up for the first game at the beginning, the coach calls him John Mazzello.
In the movie, John Mazzello bats as a right-handed hitter in every at bat. However, at the end of the film, they show actual footage of John Mazzello's final game-winning hit and, in that home video of the actual event, Mazzello bats left-handed.