In Baseball press 2 for underarm. To go back press 1.

Unlockable	How to unlock
"Split-ter	When you are pitching downwards,do a splitter and your guy will do a "Split-ter".
Fast ball	Don't press any button when throwing.
Screw ball	Press and hold A-button, when throwing.
Curve ball	Press and hold B-button, when throwing.
Splitter	Press and hold A+B-button, when throwing.
Underhand	Press and hold 2-button, when throwing.
From underhand to overhand	Before throwing, press 1-button (your remote will make a little shake) and then throw any overhand throw.