Spin Rate

Definition

Spin Rate measures the spin on the baseball when the pitch is released. It is measured in revolutions per minute.

The amount of spin on a pitch changes its trajectory. The same pitch thrown at the same velocity will end up in a different place depending on how much it spins. For instance, a fastball with a high spin rate appears to have a "rising" effect on the hitter -- it crosses the plate a few inches higher than a fastball of equal velocity with a lower spin rate -- while a curveball with a high spin rate will tend to have more break than one with less spin. Conversely, a lower spin rate on a changeup or splitter tends to create more "tumbling" downward movement.

For example: "The pitch had a spin rate of 2,500 rpm."