I've just recently been playing a lot of basketball recently & am amazed at how it was improved my overall tennis game. I feel quicker on the court. My stamina is better as is my footwork. This has resulted in better confidence & better shot-making. Obviously tennis pros on television have a lot of money at stake so it is understandable that they perhaps just stick to tennis. However, there are a few who do play other sports. I know Sampras when he played was an avid basketball player. That was very evident in his great leaping ability & excellent footwork. I think even Tommy Haas incorporated basketball training in his regimen, which they showed on the tennis channel. I'm sure many of the spanish & french players play soccer as well. Steve Nash (basketball) plays only soccer in the summer time. Can anybody think of any other examples? Also, do you think it is beneficial for tennis pros to cross-train doing other sports?