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In baseball, a sinker is a type of fastball pitch similar to the two-seam fastball which has significant downward movement. The sinker is known for inducing a lot of ground balls.[1] Pitchers who use the sinker tend to rely on it heavily and do not need to change pitch speeds as much as other pitchers do because the sinking action induces weak bat contact. Other pitchers normally change pitch speeds to achieve this effect.[2]


Before the 1950s, pitchers did not know what caused their pitches to sink or "hop". They regarded either ability as a "gift from heaven". Bill James cites Curt Simmons as the first pitcher to be able to throw both sinking and hopping fastballs, apparently indicating that it was now known how to make a pitch sink and how to make one hop.[1]

Throwing mechanics[]

One method of throwing the sinker is to simply grip the baseball along the two seams and throw it like a fastball. This makes the pitch synonymous with a two-seam fastball. However, the sinker ball pitchers may also turn the ball over just before releasing the ball, slightly increasing the pressure on the ball with the index finger.[1]

Effects on the batter[]

The sinker drop 5 to 10 inches more than a typical fastball which causes batters to hit ground balls more often than other fastballs.[1] Horizontal movement also occurs when sinkers are thrown.[2]

  1. 1.0 1.1 1.2 1.3 John Walsh. In Search of the Sinker. The Hardball Times.
  2. 2.0 2.1 Joe P. Sheehan. That Sinking Feeling. Baseball Analysts.