In 1979, 16-year-old Tracy Austin became the youngest player ever to win the U.S. Open when she defeated four-time defending champion Chris Evert 6-4, 6-3. Austin’s deep and unerring ground strokes led her to the title at Flushing Meadows again in 1981, and despite recurring sciatica, she intermittently held the No. 1 ranking. But by 1983, back and neck problems had taken their toll, forcing her to take a four-year hiatus from the sport. Austin was unable to fulfill her promise, which could have seen her challenge Evert and Martina Navratilova, the dominant forces of the decade. Today’s age restrictions, designed to protect young players from physical and mental burnout, can be traced to Austin. Now 48, she’s a sought-after commentator and covers Wimbledon for the BBC.