It does take a great hunger to be successful at anything.

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.

There is a lot of pressure on tennis players like other sports that are singular like you're not on a team. When all the pressure rides on your shoulders, it can be a lot different. Team sports you share those moments with the teammates. You share the pressures. You share the wins. You share the losses. You have a coach that can change the course of matches. But in tennis you're out there by yourself. There are no caddies. There are no coaches. You do it alone in the arena and I think that ups the ante a little bit.

Focusing on one thing can be tough, and people with fewer options are more apt to concentrate on what they're doing. There's probably something to hunger.

When your four biggest tournaments all operate relatively independently, and the ATP and WTA tour operate independently, and you have Davis Cup and Fed Cup that operate independently, it makes it a tough message.

We have a lot of options. America is a great country.

I really try not to read the tennis articles, because a lot of times they're guessing at how a player is feeling, and I like to keep myself kind of open minded about how I'm feeling, rather than have someone else explain to me what's going on.