It’s not easy to define Keith Thurman. Yes, he’s a fighter. Yes, the WBA/WBC welterweight titlist is among the world’s best 147-pounders. Yes, Thurman is an iconoclast when it comes to boxing. The 28-year-old from Clearwater, Florida, kind of marches to his own beat. On April 19, Thurman (28-0, 22 knockouts) underwent surgery to remove painful calcium deposits and bone spurs from his right elbow. Originally, he thought he would return to the ring by later this year.