Pitch (baseball)

In baseball, a pitch is the act of throwing a baseball toward home plate to start a play. The term comes from the Knickerbocker Rules. Originally, the ball had to be literally "pitched" underhand, as with pitching horseshoes. Overhead throwing was not allowed until 1884.

The biomechanics of pitching have been studied extensively. The phases of throwing include windup, early cocking, late cocking, early acceleration, late acceleration, deceleration, and follow-through. [Clinical Journal of Sport Medicine. 15(1):37-40, January 2005.Benjamin, Holly J. MD *; Briner, William W. Jr. MD +]

Pitchers throw a variety of pitches, each of which has a slightly different velocity, trajectory, movement, hand position, wrist position and/or arm angle. These variations are introduced to confuse the batter in various ways, and ultimately aid the defensive team in getting the batter or baserunners out.

To obtain variety, and therefore enhance defensive baseball strategy, the pitcher manipulates the grip on the ball at the point of release. Variations in the grip cause the seams to "catch" the air differently, therefore changing the trajectory of the ball, making it harder for the batter to hit.

Fastballs

The fastball is the most common pitch in baseball, and most pitchers have some form of a fastball in their arsenal. It is basically a pitch thrown very fast; some with movement, some without. The cut fastball, split-finger fastball and forkball are variations on the fastball with extra movement, which are sometimes called sinking-fastballs because of the trajectories. The most common fastball type pitches are:
* Four-seam fastball (rising fastball)
* Two-seam fastball
** Cutter
** Split-finger fastball
** Forkball
** Sinker

Breaking balls

Well-thrown breaking balls have movement, usually sideways or downward. The notion of a pitched ball's trajectory moving is actually incorrect a ball "moves" due to the changes in the pressure of the air surrounding the ball as a result of the kind of pitch thrown. Therefore, in actuality, the ball keeps "moving" in the path of least resistance, which constantly changes. For example, the spin from a properly thrown slider (thrown by a right-handed pitcher) results in lower air pressure on the pitcher's left side, resulting in the ball "sliding" to the left (from the pitcher's perspective). The goal is usually to make the ball difficult to hit or confusing to batters. Most breaking balls are considered off-speed pitches. The most common breaking pitches are:
* Curveball
** Knuckle curve
** Slurve
* Slider
* Screwball

Changeups

The changeup is the staple off-speed pitch, usually thrown to look like a fastball but arriving much slower to the plate. Its reduced speed coupled with its deceptive delivery are meant to confuse the batter's timing.cite web |url = http://www.hardballtimes.com/main/article/pitch-identification-tutorial/ |title = Pitch Identification Tutorial |last = Walsh | first = John |date =2007-09-19 |accessdate=2007-09-19 |work = The Hardball Times] The most common changeups are:

* Straight change
** Palmball
* Circle changeup

Others

Other pitches which are or have been used in baseball are:

*Knuckleball
*Eephus pitch
*Spitball
*Gyroball
*Shuuto
*Knuckle Slider

References