How To Throw A Curveball Correctly

When it comes to pitching, another one of the the most popular questions that is often asked, especially by younger players, is how to throw a curveball correctly.

There are two fundamental components to every pitch, and as with every pitch, when learning how to throw a curveball, you must first understand the proper grip, and then understand the proper release.

The curveball is very similar to the slider with regard to grip, with the primary distinction being a much different release point.
Most commonly, a curveball is gripped with the index finger and middle finger touching and the middle finger pressed against the seams of the baseball just above the point where the seams are closest to each other. When gripped properly and your index finger and middle finger are touching, you will find the tip of your index finger centered inside of the large cup formed by the seams at their widest point. Your ring finger and pinky should be off to the side and not making any contact with the baseball. Even though your index finger is making contact with the baseball, there should be noticeably more pressure placed on the ball by your middle finger and your thumb.

The curveball is considered an off-speed pitch because the arm puts rotation, not force, on the ball, even though it is still delivered with the arm speed of a fastball. For purposes of demonstrating the proper release point, I would point to two different positions. The first is a palm down hand position, which is the traditional release point for a fastball. The second is often referred to as a karate chop position, and is the traditional release point for a curveball.

When teaching someone how to throw a curveball, I like to describe the proper release point as being what is referred to all full supination, or in a visual sense, a full karate chop release point. It is the job of the middle finger to impart rotation, creating a spin, which when coupled with gravity, produces an outside-down action. The easiest mistake to make on this pitch is not staying on top of the ball all the way through release, or said another way, coming back to palm down position before release, eliminating the effect created by the fully supinated angle of the forearm, wrist, and hand.

There are a few variations to the curve ball as well. These include the 12-6 curve and the 10-4 curve. Both use slight variations to the basic grip and release in order to change the curve slightly. The 12-6 curve is a slider that will cause the ball to drop from top to bottom while the 10-4 slider, which is also called the 2-8 curve ball for right handers, is a more traditional type curve ball. The variations in the curve is created by different pressure points used on the ball with the thumb and fingers, causing the ball to have a different spin which will direct the curve. Most pitchers will figure out through constant experimentation and practice, the adjustments necessary in the grip to produce these different results.

When teaching someone how to throw a curveball, the best pitching coaches will ordinarily recommend that the curveball be anywhere from 13-16 miles per hour slower than one's best fastball.

One final caution and it relates to youth pitchers. A curveball is probably one of the most wearing pitches on anyones arm and should not even be introduced until age 13 at the very earliest. Coaches will routinely be asked by players younger than this how to throw a curveball, and they should all be clear about its long-term risks and discourage its use.