Spin is a separate quality: some pitchers throw hard but straight, while others (like Hill) throw soft with spin. “Spin and the ability to shape pitches has a lot to do with both the range of motion of your individual joints and, really, the elasticity of connective tissue,” Bannister says. Some players’ ligaments and tendons are stiffer and less responsive, whereas others store a higher amount of potential energy in the milliseconds prior to performing a movement.
