Table 1. Percentage comparison of the stances used when hitting forehands in a set of clay court and grass court tennis in matches performed by Roger Federer (RF)-Alejandro Falla (AF). Court Stroke Open Square Closed RF AF RF AF RF AF Clay Forehand 77 72 13 12 10 18 Backhand 6 36 22 43 72 21 Grass Forehand 72 34 19 41 9 25 Backhand 6 10 26 48 68 42