Sinking fastball
The sinking fastball is a type of fastball that moves toward the pitcher’s arm side while dropping as it approaches the plate.
In Major League Baseball (MLB), the term “sinker” typically refers to this pitch.
However, in Japan, the word “sinker” is commonly used to describe a different pitch—one that is slower and more similar to a changeup.
In MLB, some pitchers rely heavily on the sinking fastball as a primary pitch, just like the four-seam or two-seam fastball.
In contrast, it is rarely used as a main pitch in Japan.
Like the two-seam and one-seam fastballs, the sinking fastball is mainly used to induce ground balls.
Grip and Release
The finger placement is essentially the same as a two-seam fastball.
Place your index and middle fingers along the narrow seams where they are closest together, and position your thumb underneath the ball along the lower seam.
From the two-seam grip, slightly adjust the angle of the ball so that it leans a bit more toward a one-seam fastball orientation.
The arm action is the same as a standard fastball.
Do not “take something off” the pitch—throw it with full arm speed and focus on generating strong rotation.
At release, use your index finger as the primary axis to create stronger arm-side run and increased movement.
Similar to a traditional sinker, it is more difficult to generate movement with an overhand delivery.
A lower arm slot, such as a three-quarter delivery, tends to produce greater movement and sink.
The sinking fastball is most effective when it combines velocity with late movement.
Focus on maintaining fastball arm speed while refining your grip and release to maximize both sink and control.