The answer to the question of whose curveball breaks harder — that of the Yankees’ A.J. Burnett or the Phillies’ Cole Hamels — may be neither.
Zhong-Lin Lu, a professor of cognitive neuroscience at USC, along with USC alumni Emily Knight and Robert Ennis and Arthur Shapiro, associate professor of psychology at American University, developed a simple visual demo that suggests a curveball’s break is, at least in part, a trick of the eye.
Their demo won the Best Visual Illusion of the Year prize at the Vision Sciences meeting earlier this year.
Try it at http://illusioncontest.neuralcorrelate.com/2009/the-break-of-the-curveball/.
The idea is that the effect is due to the batters being forced to switch between peripheral vision and central vision during a swing.