Roddick is renowned for his booming serve
What does it take to make the leap from a player with great potential to the world's number one?
Andy Roddick blasted his way into the tennis world as a 19-year-old when he topped the junior rankings.
Two years later, only Roger Federer stood between him and the top spot.
He holds the world record for the fastest serve ever (155mph), and hits his forehand like he's swotting a fly.
I didn't think tennis was the career for me until quite late.
In late 1999, when I was 17, I wasn't doing that well in the juniors and I was ready to go to college.
My coach at the time, Tarik Benhabiles, said to me: "Give me four months, leave it until spring before you go to school".
And after working with him for four months, I was the number one junior in the world, so I thought I might go professional.
I was quite quick out of the gates during my first year as a pro. I went from being a junior one year to becoming the world number 14 the next.
It was pretty quick. I didn't struggle in the Future or Challenger tournaments, I just moved on up.
Lives: Boca Raton, Florida, USA
Fastest serve: 155 mph
Career titles: 15 including the US Open
Tarik and I will always be friends. He's been a huge influence on my life, not only on the tennis court but off it too.
I think I would still be in college if it wasn't for him so I owe a lot of my success to him.
The quarter-final against Younes El Aynaoui at the 2003 Australian Open was a special match.
The match went to five sets and I ended up winning the final set 21-19!
It was the most games that have ever been played in a final set at any Grand Slam.
The match lasted over five hours and the last set alone was two hours 23 minutes!
You never know what's going to happen going into a match, then five hours later you still don't know.
Not only was it long and dramatic but I think the tennis was at a high level. We both played close to the best of our abilities.
It has taught me a lesson.
I've been in a few situations since then where I'm a set and a break of serve down.
But I say to myself: "You've been something way tougher than this before".
It's kind of the fear of the unknown, but once you've been out there five hours, it makes it easier if you go all the way in a match again.
Roddick collapses after a marathon match in the 2003 Aussie Open
I'm a bit of a goofball off the tennis court.
I guess in England that would mean I was cheeky! You have that term here, right?
I'm always trying to play jokes on people or come up with funny one-liners.
People see me on the court and I'm pretty intense. I guess I have a bit of a temper.
So off court I'm pretty laid back, I just go with the flow.
I love bungee jumping, skydiving, anything that gets my adrenaline pumping a little bit.
The next time I go skydiving I'll be able to do it solo.
Up until now I've jumped with someone strapped to me, but I need to sit a class and then it's me on my own.
How do I do skydiving? Easy - just jump!