How to Throw a Curveball

The baseball pitching grip most young pitchers want to learn how to throw is the curveball.

Except for the release, the curveball is thrown with the same mechanics as the fastball. Once a pitcher understands that important fact, he will easily learn the proper way to throw a good curveball.

A good curve breaks both vertically and horizontally and also changes speeds. For young pitchers, a flat curve will work because the hitter will bail out. However, the older a pitcher gets, the more he needs to develop downward movement, because older hitters have learned to adjust and stay in to hit the ball. The curve that breaks down is obviously more difficult to hit since the bat is narrower than it is long.

Curveball Grip: The middle finger is the primary source of pressure and is placed against the inside of a seam. It can be gripped several ways, but the most common is the four-seam grip. In this grip, the fingers go in the open end of a horseshoe and are placed against the seam (right side for a right-handed pitcher, left side for a left-handed pitcher). The curve uses a lot of the finger, unlike the fastball, which holds the ball in the fingertips. The index finder simply lies next to the middle finger in the curve grip

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As a general rule, the more the ball is choked back in the hand, the slower the curveball will be. Each pitcher must experiment with the ball placement in the hand, grip tightness, and pitch speed. Pitchers will have many small adjustments to make before they find the best curve for them.

The thumb plays a big role in throwing this pitch. It can be either bent or straight or strait (see picture). Either way, the thumb is on the seam directly opposite that of the middle finger. The thumb and middle finger should be bisecting the ball. The bent thumb can give more flip than the strait thumb, which may cause more rotation.

The thumb’s actions are exactly the opposite of the middle finger’s actions. When the middle finger pulls, the thumb pushes. The result is the spin that makes it break.

The release point is slightly later than that of the fastball. In other words, the pitcher holds onto the ball a little longer. Adjusting the height of a curveball is very simple. If the pitch is consistently high, simply hold onto the ball a little longer. If the pitch is to low, reverse the process and let the ball go sooner.

The pitcher releases it by twisting the hand with the thumb rotating from under the ball to behind the ball, going upward to the top of the ball. The thumb will point toward the plate after the release (see picture). Simultaneously, the two fingers take the opposite path, going from top, to front side, to the bottom of the ball. The top-to-bottom rotation of the fingers is what causes the ball to spin and move in a downward path. If the ball breaks more horizontally, the pitcher is throwing on the side of the ball, and the two fingers and thumb are rotating from side to side.

When the pitcher’s arm is coming into the release area, he rotates the hand a quarter turn. The palm faces the batter until it gets into the release area, when the hand turns so that the palm now faces the pitcher. The fingers don’t stay on top, it is impossible for the pitcher to get any downward break on the curveball.  By placing the hand in this position before release, the pitcher adds consistency to his curveball delivery. From this position it is much easier to stay on top of the curve and throw a consistent curveball with a consistent break.