Which of the following was the greatest service returner in the history of the game of tennis: Andre Agassi or Martina Hingis?
Andre Agassi: Andre Kirk Agassi ( ; born April 29, 1970) is an American retired professional tennis player and former World No. 1 who was one of the sport's most dominant players from the early 1990s to the mid-2000s. Andre Agassi:  Generally considered by critics and fellow players to be one of the greatest tennis players of all time, Agassi has been called the greatest service returner in the history of the game.
i don't know