In 2015 Serena Williams, 34, won three major titles, went 53–3 and provided at least one new measure of her tyrannical three-year reign at No. 1. For six weeks this summer—and for the first time in the 40-year history of the WTA rankings—Williams amassed twice as many ranking points as the world No. 2; at one point that gap grew larger than the one between No. 2 and No. 1,000. Williams’s 21 career Grand Slam singles titles are just one short of Steffi Graf’s Open-era record. Such numbers are reason enough for Sports Illustrated to name Serena Williams its 2015 Sportsperson of the Year.