In the Spin Rate and Spin Efficiency section of this series, it was established that only three of the four spin categories affected movement – backspin, topspin, and sidespin. The black sheep of this spin-induced movement family, gyroscopic spin, finds it home in sliders.
These pitches will live close to the center of the break chart Rapsodo displays, but that obviously does not mean they do not move. From a break profile perspective, and since these pitches can typically be thrown at higher velocity than curveballs, sliders can be thought of as midpoints between fastballs and curveballs.
Gyro sliders (those with spin efficiencies <10%) will register vertical and horizontal break at or near the exact center of the break chart. This may sound strange at first, but remember that these break measurements are spin-induced measurements and that gyroscopic spin does very, very little to impact movement on the ball’s flight to home plate.
Sidespin sliders pair best with pitchers who can generate above average run and/or sink on their fastballs. These sliders, similar to sweeping curveballs, should always possess more glove-side horizontal break than vertical break, though the gyroscopic spin profile should still keep these measurements in the single-digit range.