Hitters have a lot to think about when they’re at the plate. Game situation, pitch count, pitcher tendencies and even the last few at-bats. Picking out the fast ball versus the off-speed pitch is hard enough but what if a pitcher could vary not only his speed and location but also the ball’s backspin? The visual illusion of the rising fastball depends on backspin to counteract gravitational forces during the trajectory to the plate. So, playing with different backspins would directly affect the vertical dimension of the ball flight.
Researchers at Japan’s Waseda University designed an experiment to mess with a group of pro, semi-pro and college hitters by asking them to hit pitches with varying backspins but constant speeds. Their research appeared in the Journal of Applied Biomechanics.