Curveball
In baseball and softball, the curveball is a type of pitch thrown with a characteristic grip and hand movement that imparts forward spin to the ball, causing it to dive as it approaches the plate.
The ball first leaves contact with the thumb and tumbles over the index finger thus imparting the forward or "top-spin" characteristic of a curveball.
Unlike the fastball, the apex of the ball's flight path arc does not necessarily need to occur at the pitcher's release point, and often peaks shortly afterwards.
[2] From a hitter's perspective, a curveball initially appears to travel toward a specific location—often high in the strike zone—before rapidly dropping as it approaches the plate.
These pitches are particularly disadvantageous for pitchers, as their low velocity and minimal movement often leave them high in the strike zone, making them easy for hitters to time and drive with power.
The curveball is a popular and effective pitch in professional baseball, but it is not particularly widespread in leagues with players younger than college level.
This is with regard for the safety of the pitcher – not because of its difficulty – though the pitch is widely considered difficult to learn as it requires some degree of mastery and the ability to pinpoint the thrown ball's location.
[3] 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 The New York Times, March 12, 2012, about whether curveballs alone are responsible for injuries in young pitchers or whether the number of pitches thrown is the predisposing factor.
While this pitch still drops due to gravity, the absence of significant topspin results in less vertical movement compared to other curveballs, such as the 12–6, 1–7/11–5, or 2–8/10–4 varieties.
By contrast, a slider’s spin axis is nearly parallel to the ball's flight path, similar to the rotation of a football or bullet, but slightly tilted upward toward 12 o’clock.
A slurve often occurs when a pitcher applies excessive force to a curveball with insufficient finesse, resulting in a slight pronation at the release point rather than a full supination.
The baseball's raised seams augment the ball's ability to develop a boundary layer and therefore a greater differential of pressure between the upper and lower zones.
Thus the fastball falls less than a ball thrown without spin (neglecting knuckleball effects) during the 60 feet 6 inches it travels to home plate.
However, optical illusion caused by the ball's spinning may play an important part in what makes curveballs difficult to hit.
[11] Popular nicknames for the curveball include "the bender" and "the hook" (both describing the trajectory of the pitch), as well as "the yakker" and "Uncle Charlie".
[17] In the early 1880s, Clinton Scollard (1860–1932), a pitcher from Hamilton College in New York, became famous for his curve ball and later earned fame as a prolific American poet.
"[24] In the past, major league pitchers Tommy Bridges, Bob Feller, Virgil Trucks, Herb Score, Camilo Pascual, Sandy Koufax, Bert Blyleven, and the aforementioned Dwight Gooden were regarded as having outstanding curveballs.
