Originally Posted by tennis_pro
Roddick made the overhead look like a routine shot, while Sampras had to introduce needless acrobatics to get more credit. Anyway, I'm not saying that Sampras had a weak smash, not by any means, he had an excellent overhead, just think that Roddick and Federer have better.
Besides, Sampras didn't have to backpedal much to get to that lob, the ball would land midcourt if he let it bounce.
While most pros rarely miss overheads, Sampras' vertical leap was definitely a plus because it meant that the lob had to be much "higher" (and, therefore, nearly perfect) to clear his "wing span". Backpedalling also works fine, but it robs the smash of power and forces you to rely on placement instead and there is a chance that the opponent can get it back if he guesses right.