NEW YORK, NY - SEPTEMBER 11:  A detail of the shoe of Stan Wawrinka of Switzerland during his Men's Singles Final Match against Novak Djokovic of Serbia on Day Fourteen of the 2016 US Open at the USTA Billie Jean King National Tennis Center on September 11, 2016 in the Flushing neighborhood of the Queens borough of New York City.  (Photo by Michael Heiman/Getty Images)