Pause the game and then press Square(2), Circle(2), L1, R1. You will hear a sound if you entered the code correctly. After you hear the sound press L1 + L2 + R1 + R2. This will unlock the "Game State" (edit game parameters) and the "Ball Cannon" (set pitch physics) options.
After getting hit by a pitch press Square and the player will rush the mound and fight. The downside is the player will get ejected.