curveball is a breaking pitch in baseball thrown with a characteristic grip and hand movement that impart down and/or sideways spin to the ball. It is therefore considered a type of breaking ball. Contrary to a fastball (which has only back spin), the curveball has a diagonal spin that creates a wake behind the ball, making the pitch drop on its way to the plate. A curveball is used to disrupt the opponent's timing. While it is a good pitch for doing so, it is also a dangerous pitch to throw. The increased topspin of the ball has the potential to gain tremendous backspin off of a batter's bat, giving it much added distance if well hit. For pitchers, it is better to throw a straight breaking ball, one that breaks from high to low as opposed to side to side. The simple argument for this is that the batter has 33 inches to hit a side to side pitch, while only one inch to hit an up to down pitch.

Theory

A fastball typically has backspin, giving it relatively stable aerodynamic characteristics in flight. The spin of a curveball moves in the opposite direction. This spin causes a curveball to "break", or drop down and sweep horizontally as it approaches home plate, thus frustrating the batter.

When throwing a curve, the pitcher creates downspin by rolling his or her palm and fingers over the top of the ball while releasing it. The direction of the break depends on the axis of spin on the ball. There are many variations of the curveball, but most are described in terms of their movement when superimposed on a clock. A "12–6" or "overhand" has a more or less straight downward action as it approaches the plate, while more sweeping curveballs might be described as "1–7" or "slurves". The slurve is most commonly found in left-handed pitchers, and rarely right-handed. There is no specific point where a ball breaks, but the deviation from a fastball trajectory becomes progressively greater as the ball approaches the plate. The point of breaking is normally determined by the point at which the pitcher snaps his wrist. If the wrist is rotated, or snapped, earlier in the motion the ball will have a more looping or early breaking trajectory. If the wrist is snapped later in the motion the ball will hold its path longer and curve later.

Generally the Magnus effect describes the laws of physics that make a curveball curve. A fastball travels through the air with backspin, which creates a high-pressure zone in the air ahead of and under the baseball. The baseball's raised seams augment the ball's ability to churn the air and create high pressure zones. The effect of gravity is temporarily counteracted as the ball rides on and into energized air. Thus the travel of a fastball is more or less straight, at least over the distance from the mound to home plate.

On the other hand, a curveball, thrown with topspin, creates a high-pressure zone on top of the ball, which deflects the ball downward in flight. Combined with gravity, this gives the ball an exaggerated drop in flight that is difficult for the hitter to track. The curveball may have some horizontal movement as well, depending on the tilt of its axis of spin.

At the professional level, a curveball is usually about 15 miles per hour slower than a fastball. However, curveball behavior is unique to each pitcher. Some use a more looping slow curve and some use a harder, faster slurve. The speed difference between a curveball and fastball, as well as the curveball's movement, serve to deceive the batter. Ideally, a curveball will have its greatest break just as it reaches the plate and cause the batter to swing above it.

To throw a curveball correctly, proper spin must be given to the ball as it is released. Generally pitchers grip the ball deeper into their palm and fingers than they would a fastball. Pitchers usually position their index finger aside one of the ball's raised seams for more leverage in spinning the baseball. At the release point they then roll their hand over the top of the ball to throw it forward with downspin. If this movement is poorly executed the ball will have lazy spin, not break in flight, and be much easier to hit—the "hanging curve".

When thrown correctly, it could have a huge break from seven to as much as 20 inches .

There has been debate on whether a curve ball actually curves or is an optical illusion. In 1949, Ralph B. Lightfoot, an aeronautical engineer at Sikorsky Aircraft, used wind tunnel tests to prove that a curve ball does in fact actually curve. However, optical illusion caused by the ball's spinning may play an important part in what makes curve balls difficult to hit. The curveball's trajectory is smooth, however the batter perceives a sudden, dramatic change in the ball's direction. When an object that is spinning and moving through space is viewed directly, the overall motion is interpreted correctly by the brain. However, as it enters the peripheral vision, the internal spinning motion distorts how the overall motion is perceived. A curveball's trajectory begins in the center of the batter's vision, but overlaps with peripheral vision as it approaches the plate, which may explain the suddenness of the break perceived by the batter. On whether a curve ball is caused by an illusion, Baseball Hall of Fame pitcher Dizzy Dean has been quoted in a number of variations on this basic premise: "Stand behind a tree 60 feet away, and I'll whomp you with an optical illusion!"

A popular nickname for a curveball is the "deuce", since it is commonly the number 2 pitch in a pitcher's repertoire. Catchers often use a two-finger signal when requesting the curveball. Other popular nicknames for the pitch include: "hammer", "bender", "hook", "yakker", "Public Enemy No. 1", (as coined by the Los Angeles Dodgers announcer Vin Scully, in reference to the curve ball of Dodger pitcher Clayton Kershaw and "Uncle Charlie".

There are two types of curveballs: a 12 6 curveball and a 10 4 curveball, with the main differences being in finger placement.

The curve ball (as well as the slider) is analogous to swing bowling in Cricket.

Injuries

A curveball, because of the risk of injury to the pitcher’s elbow and shoulder, can be considered a more advanced pitch, geared towards pitchers with more developed and mature arms. It is suggested that the pitcher be near 12 to 14 years old before attempting a curve ball. This restriction is not due to the ability to learn how to throw a curveball; rather, the restriction is advised to allow for proper maturity of the pitcher’s arm.

Important factors to consider before learning how to throw a curve:

• Has the child hit puberty?
• How developed are the child’s muscles and connective tissues, i.e.—ligaments, tendons, and bones?
• Is the pitcher in the middle of a growth spurt?
• Has the pitcher been taught the correct mechanics in order to throw a curveball?

The parts of the arm that are most commonly injured by the curveball are the ligaments in the elbow, the biceps and the forearm muscles.

The technique can also influence the likelihood of injury, such as whether the pitcher snaps their wrist, or twists their arm.

History

Baseball lore has it that the curveball was invented in the early 1870s by Fred Goldsmith. An early demonstration of the "skewball" or curveball occurred at the Capitoline Grounds in Brooklyn in August, 1870 by Fred Goldsmith. In 1869, a reporter for the New York Clipper described Phonney Martin as an "extremely hard pitcher to hit for the ball never comes in a straight line‚ but in a tantalizing curve." If the observation is true, this would pre-date Cummings and Goldsmith. In 1884, St. Nicholas, a children's magazine, featured a story entitled, "How Science Won the Game". It told of how a boy pitcher mastered the curve ball to defeat the opposing batters. In the early years of the sport, use of the curveball was thought to be dishonest and was outlawed, but officials could not do much to stop pitchers from using it. In the past, major league pitchers Bob Feller, Virgil Trucks, Herb Score, Camilo Pascual and Sandy Koufax were regarded as having outstanding curveballs. Steve Carlton is said to have had the best curveball in the recent modern era. Other notable pitchers who throw or threw great curveballs since 1900 are/were, Barry Zito, Sal Maglie, Dwight Gooden, Nolan Ryan, Darryl Kile, Matt Morris. Orel Hershiser, Tom Gordon, Aaron Sele, Tommy Bridges, Bert Blyleven, Clayton Kershaw, and Three Finger Brown. In 2008 Ben Sheets threw curveballs 33.0% of the time, more than any other starter, and A.J. Burnett threw them a higher percentage of the time than any other AL starter; 29.2%.[54797]

References

External links

• Version 1: Candy Cummings was the inventor of the curveball
• Version 2: Fred Goldsmith: co-inventor of the curveball or pitcher who gave first recorded demonstration of the curveball?
• Aerodynamics of a Curveball in Navier-Stokes Flow
• How to Throw a Curveball - wikiHow page outlining technique