Dont let the amount of cheats for this game fool you, because this game is really awsome. even though there are not too many cheats for it, it is still cool. there is only one hint, which is pretty cool.
Hidden Teams
Select exhibition mode. Repeatedly press L2 + R2 and the Dingers and the Islanders teams will be unlocked. A sound will confirm correct entry. The Dingers can also be unlocked in batting practice mode. Press L1 + L2 + R1 + R2 at the batting practice team selection screen and that team will appear next to the Cooperstown Legends.