Roger Federer criticized the Women's Tennis Association's age rule following Cori "Coco" Gauff's spectacular performance at Wimbledon.
Gauff became the youngest player in the Open Era to qualify for a Wimbledon singles draw and is the youngest woman in the Open Era to qualify for a Grand Slam tournament main draw. She beat Venus Williams along the way before losing to Simona Halep in the fourth round.
But the WTA's age restriction policy will limit the number of tournaments Gauff can play in.
The rule was introduced in 1994 in response to the struggles of Jennifer Capriati—a phenom who burst onto the scene at 13 in 1991.