Serena Williams turned pro in 1995, at age 14. In all the years since, she has yet to meet her match.

She has played more than 800 tennis matches, won 18 Grand Slam tournaments and set the standard for the rest of the women’s tour for more than a decade. She is 33 years old and has made comebacks from knee injuries, a sliced tendon in her foot, a pulmonary embolism and a hematoma. She hasn’t always been No. 1 in the rankings, but she is now.

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