The fake pick off is illegal
One thing that always bugged me was the fake pickoff at the end of the movie. Billy is developed through out the movie as a baseball genius, which is what allowed him to manage a team despite his age.
Yet, he doesn't know what constitutes a balk? If the film had followed the rules of the game, Griffey would have been awarded second base because it was an illegal play.
Baseball rules state a throw must be made to first base during a pickoff move or the throw is a balk.