In the opening dialogue, and again once during the movie, Brooklyn is referred to as "Brooklyn Island". It's not -- it's a part of Long Island.
The plot of the movie largely hinges on Brooklyn's poor attendance, yet all the stock footage of the ballpark shows the place jammed with fans.
In the final baseball sequence, Brooklyn is beating St. Louis 2-1. There are 2 outs and bases loaded and the relief pitcher runs the count to 3-2. The announcer twice indicates that the next pitch will decided the pennant and even says "If it's a strike, it's Brooklyn. If it's a ball, it's St. Louis." Not true. A ball would walk in a run TYING the game, not giving the game to St. Louis. A baseball announcer would surely know that.