Baseball pitch

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. Overhand 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.

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, thereby changing the trajectory of the ball, making it harder for the batter to hit.

The selection of which pitch to use can depend on a wide variety of factors including the type of hitter who is being faced; whether there are any base runners; how many outs have been made in the inning; and the current score.

The responsibility for selecting the type of pitch was traditionally made by the catcher by relaying hand signals to the pitcher with the fingers, usually one finger for fastball and/or the pitcher's best pitch, with the pitcher having the option to ask for another selection by shaking his head. However, current form is to have the manager or a coach relay the pitch selection to the catcher, via secret hand signals to prevent the opposing team from having the advantage of knowing what the next pitch will be. Starting pitchers typically throw more pitches than relievers.

The fastball is the most common pitch in baseball, and most pitchers have some form of a fastball in their arsenal. Most pitchers throw four-seam fastballs. It is basically a pitch thrown very fast, generally as hard as a given pitcher can throw while maintaining control. Some variations involve movement or breaking action, some do not and are simply straight, high-speed pitches. While throwing the fastball it is very important to have proper mechanics, because this increases the chance of getting the ball to its highest velocity, making it difficult for the opposing player to hit the pitch. The cut fastball, split-finger fastball, and forkball are variations on the fastball with extra movement, and are sometimes called sinking-fastballs because of the trajectories. The most common fastball pitches are:

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