In November 2010, 20-year-old Caroline Wozniacki surged past Serena Williams to grab the No. 1 ranking — and she’s holding tight. Wozniacki has won more matches than any other player on the tour this year and has done so without any of the swagger that could accompany a woman who has contested a Grand Slam final and counts Rolex as a sponsor. The daughter of Polish immigrants to Denmark, she speaks six languages — including Russian and Swedish — and keeps busy off the court by playing the piano and baking with her mom. “I love the entertainment business, so if I weren’t playing tennis, maybe I’d be an actress or something along those lines,” she says. She also has ambitions to attend Yale University when she hangs up her racket. “I think they have an architecture major, so I would love to study that, and also English.”