New York: Two 23-year-olds, Milos Raonic and Grigor Dimitrov, broke through to their first major semifinals at Wimbledon.
Perhaps this year's U.S. Open will be the tipping point for the rise of a new generation. But recent history suggests that if an outsider seizes on the trace of vulnerability in the "Big 4" to win in New York, it's more likely to be a veteran.
"We didn't have many young players who were able to challenge for top spots and win Grand Slam titles," Wimbledon champ Novak Djokovic said. "So this is something that is happening now, but it's still a long way to the Grand Slam title. It's not something that can happen overnight."