LONDON, ENGLAND - JUNE 26: A general view of centre court with roof closed as Roger Federer of Switzerland serves during his Gentlemen's Singles second round match against Gilles Muller of Luxembourg on day four of the Wimbledon Lawn Tennis Championships at the All England Lawn Tennis and Croquet Club at Wimbledon on June 26, 2014 in London, England. (Photo by Jan Kruger/Getty Images)
