http://www.sciencenews.org/view/feature/id/337209/title/Brainy_Ballplayers So all I need to do is watch youtube video of Federer, Nadal, and Djokovic . "Scientists think brain cells known as mirror neurons may help. The value of reflection When a person watches someone else performing an action, the same neurons that would fire if the observer were replicating that action become active — even if that observer is standing completely still. This neural activity is the brain’s way of simulating the motion being witnessed, and can help an athlete reproduce those movements. Mirror neurons thus provide “a system for matching what you do with what you see others doing,” says Salvatore Aglioti of Sapienza University of Rome. "