sports science: tennis players use math for net gains

Who knew? Your favorite tennis star may also be a master of Bayesian probability theory, according to a study in the Jan. 15 Nature. Konrad P. Kording and Daniel M. Wolpert of University College London report that the sort of visual and spatial judgments a good tennis player’s brain has to make when she or he returns a serve are based on mathematical principles formulated by Thomas Bayes over 200 years ago. (Bayesian theory, which concerns how outcomes are affected by prior knowledge, helped give rise to modern statistics.) The researchers tested people playing a computerized game that required them to point to where they thought a target sphere would land, similar to a tennis player having to judge an opponent’s shot. It appears that good players not only used information on what they saw around them, but also used judgments they had made about variations in the speed and trajectory of the ball from previous trials.

This news brief appeared in the Discoveries column of the Boston Globe’s Health/Science section on 1/20/2004.