Pitch Movement – Curveball

Pitch Classification

The curveball is a type of pitch in baseball thrown with a characteristic grip and hand movement that imparts forward spin to the ball causing it to dive (i.e. “break”) in a downward path as it approaches the plate.

This pitch is thrown with topspin which creates a higher pressure zone on top of the ball, which deflects the ball downward in flight. Instead of counteracting gravity, the curveball adds additional downward force, thereby gives the ball an exaggerated drop in flight.

Also know as the bender, the hook, yakker, The Hammer, Lord Charles, The Uncle Charlie, The Duce and The Big Nasty,

Best Use

Since most batters prefer an inside pitch instead of outside pitch, right-handed pitcher usually throws to right-handed batter and left-handed pitcher to left-handed batter.

Grip

The curveball is gripped much like a cup or drinking glass is held. The pitcher places the middle finger on and parallel to one of the long seams, and the thumb just behind the seam on the opposite side of the ball such that if looking from the top down, the hand should form a ‘C shape’ with the horseshoe pointing in towards the palm following the contour of the thumb. The index finger is placed alongside the middle finger, and the other two extraneous fingers are folded in towards the palm with the knuckle of the ring finger touching the leather. Occasionally some pitchers will flare out these two fingers straight and away from the ball to keep them clear of the throwing motion. The curveball and slider share nearly identical grips and throwing motion.

The delivery of a curveball is entirely different from that of most other pitches. The pitcher at the top of the throwing arc will snap the arm and wrist in a downward motion. The ball first leaves contact with the thumb and tumbles over the index finger thus imparting the forward or ‘top-spin.’ The result is the exact opposite pitch of the four-seam fastball’s backspin, but with all four seams rotating in the direction of the flight path with forward-spin, with the axis of rotation perpendicular to the intended flight path (like a bowling ball).

The amount of break on the ball depends on how hard the pitcher can snap the throw off, or how much forward spin can be put on the ball. The harder the snap, the more the pitch will break. Curveballs primarily break downwards, but can also break toward the pitcher’s off hand to varying degrees. Unlike the fastball, the height of the ball’s flight path arc does not necessarily need to occur at the pitcher’s release point, and often peaks shortly afterwards. Curveballs are thrown with considerably less velocity than fastballs, because of both the unnatural delivery of the ball and the general rule that pitches thrown with less velocity will break more.

Pitch Movement

From a hitter’s perspective, the curveball will start in one location (usually high or at the top of the strike zone) and then dive rapidly as it approaches the plate. The most effective curveballs will start breaking at the height of the arc of the ball flight, and continue to break more and more rapidly as they approach and cross through the strike zone. When thrown correctly, it could have a break from seven to as much as 20 inches in comparison to the same pitcher’s fastball.

“Hanging” curveball is when the ball does not drop off, which makes it easier for a batter to hit the ball out of the park.

What Does the Batter see?

From a hitter’s perspective, the curveball will start in one location (usually high or at the top of the strike zone) and then dive rapidly as it approaches the plate. The most effective curveballs will start breaking at the height of the arc of the ball flight, and continue to break more and more rapidly as they approach and cross through the strike zone. When thrown correctly, it could have a break from seven to as much as 20 inches in comparison to the same pitcher’s fastball.From a hitter’s perspective, the curveball will start in one location (usually high or at the top of the strike zone) and then dive rapidly as it approaches the plate. The most effective curveballs will start breaking at the height of the arc of the ball flight, and continue to break more and more rapidly as they approach and cross through the strike zone. When thrown correctly, it could have a break from seven to as much as 20 inches in comparison to the same pitcher’s fastball.

Injury Risk

Due to the unnatural motion required to throw it, the curveball is considered a more advanced pitch and poses inherent risk of injury to a pitcher’s elbow and shoulder. There has been a controversy, as reported in 2012 in the ‘New York Times,’ about whether curveballs alone are responsible for injuries in young pitchers or whether the number of pitches thrown is the predisposing factor. In theory, allowing time for the cartilage and tendons of the arm to fully develop would protect against injuries. While acquisition of proper form might be protective, Dr. James Andrews is quoted in the article as stating that in many children, lack of proper mechanics, sufficient neuromuscular control, and fatigue make maintenance of proper form unlikely.

For 13 or younger players, they should focus on fastball (4 seam and 2 seam), changeup and sinker and stay away from breaking pitches due to associated increase in injury risk.