Factual error: In the final game, the Pittsburgh manager calls for a left-hander in the bottom of the ninth inning. The pitcher strides to the mound, Roy takes his stance in the batter's box...and no warm-up pitches are taken. I understand that a pitcher isn't required to take warm-up pitches, but no pitcher who throws smoke would be willing to cut short his career just to get the game over.
Factual error: After the Knights clinch a tie for the pennant and are celebrating in the clubhouse, Hobbs tries to call Iris on a pay phone that is of early 50's vintage. The movie was set in 1939.