How to throw a curveball like Tim Lincecum or with the Sandy Koufax grip
Why is the curveball so popular?
The curveball is one of the most popular pitches in baseball. The key to this pitch is the diving movement of the ball. It's slower than a fastball, but it can be a lot harder to hit because it's hard for a hitter to judge where the ball is going to be as it crosses in front of him. The spin on the curveball is the exact opposite of a fastball.
I consider Sandy Koufax to be the best curveball pitcher of all time. Bob Feller also had a great curveball. Tim Lincecum has one of the best curveballs in the modern game.
I'm going to show you how you can improve your curveball and show you the best grip to use. Because of the violent wrist snapping movement, it's recommended that you do not throw curveballs until you are about 16 years old, after your arm has had a chance to develop and get strong enough for the curveball. You can cause elbow and shoulder damage if you throw curveballs too often at too young an age.
The curveball grip
The key fingers for my curveball are the middle finger and the thumb. Grip the ball so your middle finger rests along a seam with the seam on the right of your finger (assuming your are right handed). Your thumb will also rest along a seam on the bottom of the baseball with the seam at the right of your thumb.
Throwing the curveball
When you're bringing your arm forward in your throwing motion, your thumb should be facing the batter. Before you release the ball, rotate your wrist and hand inward. It's the same motion as if you were tightening a screw with a screwdriver. You want your middle and index finger (which should be positioned tightly against one another on the ball) to come over the top of the ball. The ball should snap up and out of your hand and forward toward the target. The purpose of this motion is to get the ball to rotate forward, in the same direction the tire on a car would spin as the car moves forward. Note that a fastball produces backward spin. The overall effect will be that the ball comes out of your hand going slightly upward, but then will have the illusion of diving downward hard as it approaches the plate.
I've found some videos of some good curveballs. The Barry Zito curveball is an example of a 12 to 6 curve, which means its movement is from up to down without much side to side movement. Notice how high the ball goes before diving down. The other type of curveball is also called the slurve, and for a right handed pitcher it moves from up and inside to down and away. The movement on these is not as great, but because it's moving from side to side it can still be very effective.
The following are videos of some really good curveballs: