In the early innings, home plate has seven sides, but in the ninth inning, home plate has five sides.
After Dizzy Dan leaves the train, the horn player (who resembles Porky Pig) is wearing a purple uniform. Before that, the uniform was green.
In the setup for the cartoon's finale, the score is supposedly 3-0 Giants. But earlier, with the score at 2-0, Claude gave an in-the-park home run to a dachshund and a four-base error to Dizzy Dan, meaning the score should be 4-0, and Claude's grand slam should have tied the game, not given him the win. A similar, but less game-breaking, math error happened in Baseball Bugs (1946), another Friz Freleng production.
The home plate shown has seven sides - Home plate should have 5 sides.
In the ninth inning, home plate has five sides, but is positioned 180 degrees off - the V-shaped part of the plate should be located toward the catcher, marking the point where the base lines meet.
When Claude throws a pitch that makes the weenie dog Giant dodge it, the umpire shouts "foul!" He should have shouted "ball!" because the ball makes no contact with the bat.
When Claude hits his home run, there is no sign of the three runners Dizzy Dan had just walked.