12. Rafael Nadal
Career years: 2002-Present
Another athlete, another set of stans seeking validation. There's no doubt that he's the rightly crowned "King of Clay"—eight French Open titltes in nine years speaks for itself. Nadal only (using "only" feels harsh here, but such scrutiny is needed when evaluating the tennis pantheon) has three Grand Slam outside of Roland Garros' clay courts, leaving the door wide open for brutal "Rafa Nadal or Roger Federer?" debates. Federer's 237-week stretch as the world's No. 1 and his higher number of Grand Slam championships should make it an open and shut case for Federer, but Nadal stans will never have it. Nothing is worse than a pack of stans clutching at straws.