ESPN Sport Science - Serena's serve

about an hour ago

As Serena Williams makes her attempt at completing the calendar Grand Slam, she'll depend a lot on her massive serve to beat the field. John Brenkus and the ESPN Sport Science team reveal that there's more than just power to her game.

ESPN Sport Science - Hard Court Slide

about an hour ago

Sliding use to be seen only on clay courts, but in recent years, tennis players are using this technique on hard court surfaces