These cheats work at the versus screen.

• Unlimited Turbo: X, X, X, X, Y, Y, Y, Y, B, B, B, B, DOWN
• Softball Mode: X, X, Y, Y, Y, Y, B, B, DOWN.
• Ball Is Rubber: X, X, Y, Y, Y, Y, B, B, UP.
• Max Out Speed: B, B, B, LEFT.
• More Time After Each Play: X, Y, Y, B, B, B, LEFT.
• Big Heads: X, X, RIGHT.
• Tiny Heads: X, X, LEFT.
• Max Out Batting: X, X, X, LEFT.
• Max Out Power: Y, Y, Y, LEFT.

At the Title Screen or the Main Menu press Y, X, R to unlock all Fantasy Teams and Fantasy Stadiums.