Serena Williams prepares to retire from tennis -- and the greatest career in sports history.

As the clock turned to the year 2000, ESPN put out its rankings of the greatest athletes of the 20th century. The list was objectionable on several fronts: Babe Ruth ahead of Muhammad Ali? Secretariat – yes, the horse – ahead of Oscar Robertson? Ahead of Lawrence Taylor? But the worst part about the list was there were just five women in the top 50, with Chris Evert squeaking in at number 50. The highest ranked (23rd) was track-and-field legend Jackie Joyner-Kersee. This arid landscape was the sports world that Serena Williams audaciously set out to rule.

In the year 2000, Serena Williams was a 19-year-old tennis prodigy still playing in the shadow of big sister Venus. But Serena had already won the U.S. Open at 17, and her confidence was running high. That momentum would last another 22 years. She now has the greatest career in the history of professional sports.

With Serena Williams set to retire after the forthcoming U.S. Open, it is worth taking stock of the magnitude of what she has accomplished. When she turned pro, it was 1995 and she was 14. She made $250 in her first pro match. Now Serena’s career ends 27 years later with 23 Grand Slam singles titles and 14 doubles titles to her name. Her career is older than five-time Wimbledon champion Bjorn Borg was when he retired.

The length of Serena’s dominance is rivaled historically only by people like quarterback Tom Brady or basketball king LeBron James. But her career accomplishments also dwarf those of Brady and James precisely because of what Serena had to overcome while also being unquestionably and undeniably herself. She showed the world you don’t have to “get in where you fit in.” She persevered in situations that neither Brady nor James could understand: winning the 2017 Australian Open while eight weeks pregnant? Coming back to her sport after almost dying during childbirth? That’s Serena. And of course, Serena Williams did not only survive the very white, often hostile world of tennis. She thrived. Her hard-fought success blasted caverns in the country club and inspired a new generation of young Black girls to reach for a racket, believing that this sport is now for them too.

She also inspired the pen of author and poet Claudia Rankine, who wrote, “Serena and Venus brought to mind Zora Neale Hurston’s ‘I feel most colored when I am thrown against a white background.’… Serena and Venus win sometimes, they lose sometimes, they’ve been booed and cheered, and through it all and evident to all were those people who are enraged they are there at all – graphite against a sharp white background.”

The unimpeachable success against this “all-white background” is precisely why Williams and her body of work stand alone.

That rather silly, staid list of the 20th century’s greatest athletes contained not a hint of who was coming in like a whirlwind. Now Serena is the standard, and everyone else is looking up.

DAVE ZIRIN is the sports editor of The Nation and the author of The Kaepernick Effect: Taking a Knee, Changing the World.