It is very dangerous to have your self-worth riding on your results as an athlete.

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.

Getting to number one in the world without a coach is highly unlikely.

Without a doubt, there's huge satisfaction when a relatively smaller nation can take on a bigger nation and defeat them. There's a lot of pride in that.

Many books have been written about what the X-factor is, what separates people who win big matches versus those who struggle. Some of it's innate, but there's a piece of it that's learned, embracing those moments.

Us going out there and performing our best. That's how I define success. I'm not going to define it for us by the wins and the losses as much as by the effort and how we handle ourselves.

There's a reason why Federer and Nadal are so gracious when they lose. They sleep well at night knowing that they've given their best.