Patrick Mouratoglou, who helps coach Serena Williams, compares the 15-time Grand Slam champion to 17-time Grand Slam titlist Roger Federer.

“I always compare her to Roger (Federer) on the men’s side because it’s the same,” Mouratoglou told TennisShorts.com. “They’re really very, very different because they still keep unbelievable motivation for the game; for winning and making history. She always wants to improve, she always wants to learn new things and always wants to keep on being competitive. It shows how much she loves tennis.”