Martina Navratilova (Czech: Martina Navrátilová born Martina Šubertová October 18, 1956) is a retired Czech and American tennis player and coach. Billie Jean King, former World No. 1 player, said in 2006 that Navratilova is "the greatest singles, doubles and mixed doubles player who's ever lived." In 2005, Tennis magazine selected her as the greatest female tennis player for the years 1965 through 2005. Tennis historian and journalist Bud Collins has called Navratilova "arguably, the greatest tennis player of all time."