I can definitely say the same thing [discussing Steffi Graf's claim that she had played against at least one top player who used steroids]. Steroids can really make a difference, physically and mentally. I'd be really disappointed if I had been ranked No. 2 behind someone who took steroids.

If you're a champion, you have to have it in your heart. You can have the greatest coaches in the world, all the opportunities to play, and the greatest equipment, but if you don't have it inside, you're not going to make it. On the other hand, if you don't have any of those luxuries but you have heart and courage and the guts to go out there and grind it out, then you'll make it.

Ninety percent of my game is mental. It's my concentration that has gotten me this far.

Losses are always a relief. They take a burden off me, make me feel more normal. If I win several tournaments in a row I get so confident I'm in a cloud. If I lose I go back to the dressing room and I'm no better nor worse than anyone else. A loss gets me eager again.

You've got to take the initiative and play your game. In a decisive set, confidence is the difference.

My first U.S. Open I think was just very special for me because that was sort of the beginning of what was a 'Cinderella' story for me.

Relationships are give-and-take, and when you're a tennis player, you're certainly not giving. You have to be self-absorbed. It has to be about you.