British qualifier Marcus Willis gave Wimbledon fans the ultimate feel-good underdog story at the 2016 Wimbledon. This week, the 30-year-old Briton closed the curtain on his pro career. Willis announced his retirement on social media. "Tennis, it's been one hell of a ride," Willis wrote on Twitter. "I've decided that I'll be retiring as a professional tennis player after … [Read more...] about Marcus Willis Announces Retirement From Pro Tour