Former Roland Garros champion Guillermo Vilas tells Wearetennis.com that the key reason why he and other excellent-clay courters had success on clay was because they knew how to slide.
“Nadal, Borg and I are big ‘sliders’: we know perfectly how to slide, brake and steer on clay, without getting carried away,” he said. “If Americans never win at Roland Garros it’s because they brake with their toes, while the best is to slow down by putting your foot sideways, a bit like skiing. If you run fast and you do not know how to stop, you end up in Canada.”
http://www.tennis.com/pro-game/2013/04/vilas-nadal-borg-and-i-are-p...