Despite being currently ranked 772nd in the world, Englishman Marcus Willis has advanced to play none other than Roger Federer on Centre Court at Wimbledon. Federer is making quick work of him, but that hardly matters. Willis has no business being there in the first place.The man has made quite the turnaround since his days playing at the Knoxville Challenger tournament in 2014, where he was seen toting around a can of soda, a candy bar, and a sizeable paunch during the match. The announcer—they had an announcer for the Knoxville Challenger, so at least there's that—was absolutely beside himself. "He's eating a Snickers? Come on, this is all a joke. I feel like this is a put on, right?"Willis guesses he weighed as much as 225 pounds at his heaviest, and generally treated his body in the exact opposite way one would expect from a supposed professional athlete. He earned and embraced the nickname Cartman—a reference to the fat shithead on South Park—and even calls himself a "tubster" on Twitter. Willis toiled away in the lower ranks of tennis, peaking at No. 322 in the world before spiraling down to 785th last month. With the urging of his girlfriend, however, he is now focused on turning this into a real thing.Willis, ranked 775th before the qualifying tournament, had nearly given up on his dreams of reaching Wimbledon and was planning to move to Philadelphia, where offers of coaching jobs were waiting."I was adamant I was going to go to America to coach," Willis said. "I had called up someone about the visa — and then I met a girl. She basically told me I was an idiot and that I should keep going, and I'm very grateful for that."He then entered the Wimbledon main draw by winning three qualifying matches and then won his opening round match against the 53rd-ranked Ricardas Berankis on Monday. Now he's playing Federer on Centre Court. Federer won the first two sets 6-0, 6-3 so get over to ESPN and watch Willis while you still can.