Serena Williams just beat out American Pharaoh as Sports Illustrated's 2015 Sportsperson of the Year . The title makes sense not only because she's a person and American Pharaoh is not, but also because the 34-year-old tennis legend won 53 of her 56 matches this year, maintained the top Women's Tennis Rankings spot every week of 2015, and holds a jaw-dropping 21 Grand Slam titles to date.Williams' skill on the court isn't the only reason the magazine chose the athlete. "We are honoring Serena Williams too for reasons that hang in the grayer, less comfortable ether, where issues such as race and femininity collide with the games," Sports Illustrated's Christian Stone writes . Williams' profile details her advocacy around race alongside her tireless dedication to her sport — "I do want to be known as the greatest ever," she states.The magazine also nods to Williams' contributions to the conversation on body positivity. "She was a difference-maker in other areas," Stone writes, "speaking out against body-shamers in both words and actions, posing for the Annie Leibovitz–shot Pirelli calendar in only a bikini bottom. The cover shot of this issue? Her inspiration, intended, like the Pirelli shots, to express her own ideal of femininity, strength, power." Her stunning cover captures all three. View Sports Illustrated's video below for more Serena.