Two other American tennis players win a lot of doubles tournaments when they are healthy and focused.
Asked what it is like to face Venus and Serena Williams on a doubles court, Lisa Raymond said it is just about what it looks like.
"It's just a lot of power coming at you," said Raymond, who, with partner Liezel Huber, lost to the Williams sisters in three sets last year in the Wimbledon semifinals after winning the first set. "I think you're playing the best server of all time in women's tennis in Serena Williams, and her sister's not too shabby with her serve. You have to have a very specific game plan, and you have to follow it to a T, because if you don't, they're going to make you pay."