Throwing a proper curve ball requires that the pitcher maintain a proper grip throughout the throwing motion. A snap of the wrist at the point of release and a strong follow through give it the spin that makes it curve.
- Find the proper grip
Grip the ball with the middle and index fingers together across the widest part of the seam, or, alternately, with the index finger running along the seam on the pinky side. Maintain a tight grip on the ball with your two fingers and thumb while keeping the ball from touching the palm. This will help generate the topspin necessary to make the ball drop as it reaches its target.
- Use the same arm motion and speed as you would for a fastball
Keep your elbow level with or above your shoulder. Your general motion should be the same as the one you use for your fastball. The spin on the ball will naturally slow it down and make it move.
- Snap your wrist on the release
As you release the pitch, turn your wrist and snap it down, rotating your thumb upward and your middle finger downward. Release the ball close to your body, or the rotation won't be sharp enough for it to curve properly. A curve ball with a loose rotation usually ends up hanging, which makes it one of the easiest pitches to hit.
- Follow through and get into fielding position
The follow through is critical to making a curve ball break. After you release the ball, the back of your hand should be facing home plate. Your pivot foot should continue forward from the mound. Let your throwing arm swing across your body, allowing you to assume your fielding position.