Wimbledon, England: For several years now, a trickle of promising young players have bubbled up, threatened to erode the top layer of men's tennis, and receded again. Roger Federer and Rafael Nadal have held firm, allowing room only for Novak Djokovic, then for Andy Murray. (How Roger Federer beat Milos Raonic to set up title clash vs Djokovic)
Only twice in the past 37 Grand Slam tournaments, going back more than nine years, has someone outside that Big Four won a title: Stan Wawrinka at this year's Australian Open and Juan Martin del Potro at the 2009 U.S. Open. No place, however, surrenders to tradition as reluctantly as Wimbledon, where one of the Big Four has won the past 11 times. It will be a 12th come Sunday, when Djokovic and Federer meet at Centre Court.
On a warm and windy Friday, Djokovic and Federer were presented with two more contenders, a pair of 23-year-olds rising through the rankings.