I know it may seem like an absurd question. Sampras is an incredible player. He had huge weapons and he has the most Grand Slam titles of any player in history. But, the fact is he did lose. He never won more than two Slams in a season, meaning that beyond clay, he lost at a Slam where the surface was favorable to him. I realize that any weaknesses may be fleeting, not arising consistently. But, I think it's an interesting discussion. How does Sampras lose to someone like Yzaga at the USO? Of course, a lot of his losses weren't to pushovers, but to legit champions in their own right, but the question remains. There had to be something, at various times, that enabled others to get the upper hand. Structural weaknesses (strokes), strategy, mental components (focus, intensity), physical, anything?