Chris Evert

Chris Evert never lost a Grand Slam final until her 19th appearance, going 18 for 18—a record unmatched by any player in tennis history. She won 18 Grand Slam singles titles, matching Martina Navratilova's tally, and maintained a career win-loss record of 1,309-146 (89.96%), the highest winning percentage in professional tennis history. Her rivalry with Navratilova spanned 80 matches over 16 years, with Evert winning 37 of those encounters. She reached at least the semifinals of 52 of her 56 Grand Slam tournaments, an extraordinary consistency rate of 92.9%.