Why does the knuckleball dance?

Imagine…you are up to the plate facing the famous Tim Wakefield from the Boston Red Sox. He winds up and throws. You watch the ball leave his hand, but as it comes near you…it doesn’t seem to be spinning…or following the path you expect. You swing... "STRIKE!" That pitch you just missed was called a knuckleball.

The knuckleball is one of the hardest pitches to hit, catch, and throw in the game of baseball. If you have ever played and faced a knuckleballer, you will know that the ball tends to dance and move as it is coming toward you. You probably will not know where it will be when it gets to you…earning yourself a strikeout or a walk.

This pitch is designed to minimize the spin of the ball when it is thrown. This lack of spin causes the ball to change paths and move in the air. If thrown correctly, it can dip, dive, and sometimes vibrate in flight, tricking the hitter. The dancing that the ball does refers to the stitching of the ball randomly changing orientation.

It also has a very slow spin, aiming to have about one and a half to two rotations from the pitcher's release to the catch. The spin is caused by the Magnus effect. This is where the air mass is deflected in one direction and the ball mass is deflected in the other direction. With the knuckleball, the center of mass of the ball is constantly changing direction, and with it the air mass must change too.

With this movement, the seams (stitches) slowly move and cause the air to separate from the ball. The orientations of the seams cause the air to push the ball causing it to go in different directions giving the illusion of dancing.

"Knuckleball" comes from the original grip of the ball; the knuckles gripped the ball instead of the fingers and then pushed with the release. This technique has been altered over time to the pitcher digging the fingernails of the middle and pointer fingers into the ball, with the thumb and pinkie as a support, but still pushing the ball with the release.

When thrown, every pitch can have control problems; however, the knuckleball is one that can be the most difficult to master. If a pitcher can learn how to throw it, it can be a very dangerous weapon in the pitching game. So watch out when you face one…you may win, but you also may lose…especially if you face a guy like Wakefield...don’t worry, he is been on the DL most of this season.