Billie Jean King (née Moffitt) (born November 22, 1943, in Long Beach, California) is a retired tennis player from the United States. She won 12 Grand Slam singles titles, 16 Grand Slam women\s doubles titles, and 11 Grand Slam mixed doubles titles. King has been an advocate against sexism in sports and society. She is known for the \"Battle of the Sexes\" in 1973, in which she defeated Bobby Riggs (who was 55 at the time), a former Wimbledon men\s champion. King is the founder of the Women\s Tennis Association, the Women\s Sports Foundation, and World Team Tennis, which she founded with her former husband, Lawrence King.
Who is the greatest grass court player?