How to throw a knuckleball

The gripThe pitch is not thrown with the knuckles, as the name suggests, but with the tips of the fingers and the nails dug into the ball just above the seams. Some pitchers, including the Mets' R.A. Dickey, grip the ball with the index and middle finger. Other pitchers believe they get more action on the ball by gripping it with three fingers - index, middle and ring fingers.

The deliveryKeeping the wrist straight, the pitch is made by outstretching the fingers at the release and pushing the ball toward the plate. The ball releases with little or no rotation.

The resultThe lack of spin causes the air around the ball to become turbulent, which produces the unpredictable flutter effect, making it hard to hit and tough to catch.