Pitch (baseball)

In baseball, the pitch is the act of throwing the baseball toward home plate to start a play. The term comes from the Knickerbocker Rules. Originally, the ball had to be thrown underhand, much like "pitching in horseshoes". Overhand pitching was not allowed in baseball until 1884.

The biomechanics of pitching have been studied extensively. The phases of pitching include the windup, early cocking, late cocking, early acceleration, late acceleration, deceleration, and follow-through.^[1]

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 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 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 existing score. Pitchers may bounce their pitches in the dirt before they reach the batter, but these pitches are ruled balls even if they pass through the strike zone.^[2]