Steffi Graf

Steffi Graf remains the only player in tennis history to achieve the Golden Slam—winning all four Grand Slams plus Olympic gold in a single calendar year (1988). Her 22 Grand Slam singles titles are one fewer than #1 Serena Williams, but she holds the longest tenure as world number one in women's tennis history at 377 weeks, 58 weeks longer than the runner-up. Graf's forehand was lauded as the most technically complete shot in women's tennis, and John McEnroe called her the greatest player of all time, male or female. She won 107 career titles, with a win percentage of 88.7% across 902 matches.