Esther Vergeer of the Netherlands serves against Marjolein Buis of the Netherlands during the 2011 U.S. Open at the USTA Billie Jean King National Tennis Center on Sept. 8, 2011 in New York City.
Esther Vergeer is the Steffi Graf of wheelchair tennis. In singles she has won 21 Grand Slam titles and three Paralympic gold medals. She has also won more than 450 matches in a row—a streak that stretches back nearly a decade to January 30, 2003. “I’ve never felt comfortable calling myself the best or the most dominant athlete,” Vergeer told TIME ahead of the 2011 Championships at Wimbledon. “But I suppose I’ve stopped worrying about my record because it does seem pretty unlikely that anyone will match it, at least in the foreseeable future.” Vergeer lost the use of her legs when she was eight years old as the result of surgery meant to correct a spinal defect.