Grigor Dimitrov
Credit: Photograph by Theo Wenner

Age: 22

Born: Haskovo, Bulgaria

Rank: 34

Profile: Called "little Federer" for his fluid strokes, he's a perpetual threat, particularly on hard court, with a dangerous topspin forehand and a creative, some say restless, style of play.

What opponents fear: "That they're playing me," he says, laughing. "Actually, I'm sure they're worried about playing too many balls to my forehand."

Indulgence: "I like everything on wheels: BMX, motorbikes, downhill mountain biking. I was doing BMX when I was younger – for a while, I was competing, and I was into motorbikes. I was all over the place. I had a couple of bad falls, and I figure tennis is more important, so I just put that away."