I think there's no reason the Davis Cup couldn't be as powerful and popular and profitable as any of the four majors are today, given some changes.

If they had rankings in baseball, maybe I would have been able to do the math and figure out my chances of being a professional baseball player versus a tennis player. But that was the decision-maker for me, I just thought I was better in tennis.

I've been lucky enough to primarily work for myself over the years.

People handle stress in different ways.

Tennis is more than just shots. It's about being clutch and beating the people on the other side of the net.

I think the Davis Cup has some untapped potential. It should be as prominent as the Grand Slams when it takes place. If you put it together with Fed Cup for an organized, nationalistic team competition taking place in a central location for two weeks, I think that would be beneficial from a fan interest stand point, from a media stand point and from a television stand point.

You have to be extreme to be exceptional. I couldn't revel in being number one. I had to get to zero. When my fitness was at its peak, I was intimidating. I made guys cave in. They'd be dejected in the locker room after matches, and I'd go out for a run, as if it wasn't enough. I'd rub it in their faces. I meant to do that.