Activating cheat mode

Press Start to pause the game. Press Triangle, Square, X, Circle(3) on controller two. A piano sound will confirm correct code entry. 
Submitted by Hideyoshi

Choose inning

Enter cheat mode (Above) and press X. The phrase "Let's go to Inning" will appear in the upper left corner. Press X repeatedly to select the desired inning. Press Start to resume the game. 
Submitted by Hideyoshi

CPU vs. CPU

Enter cheat mode and press L2. Press Start to resume the game. To resume human control, enter cheat mode and press L2 again. 
Submitted by Hideyoshi

Automatic home runs

Enter cheat mode and press L1. The phrase "home run" be spoken to confirm correct code entry. Press Start to resume the game. Any hits will be home runs. To resume normal batting, enter cheat mode and press L1 again.