Throwing a Curveball

When the Philadelphia Phillies meet the New York Yankees this week in the 2009 World Series, it’s a safe bet that a batter will swing at a curveball and miss. Why is that pitch so difficult to hit?

A mind-bending animation created by four visual researchers demonstrates that the curveball is a simple trick of the eye. When batters try to gauge their approach to the ball, they must make a mid-swing switch between peripheral and central vision.

The animation — created by visual researchers from American University, Dartmouth College, the State University of New York College of Optometry, and the University of Southern California — took first place this past May in the sixth annual Best Visual Illusion of the Year Contest, sponsored by the Neural Correlate Society.