Is Serena Williams the GOAT? Yes. No. Probably. Maybe. Without a Doubt.

In the stands this month at the Western & Southern Open in Ohio there seemed to be no debate.

There were shouts of “GOAT!” in Serena Williams’s direction and banners that read “GOAT” in her honor.

In February, Williams appeared to be in a similarly conclusive frame of mind during Milan Fashion Week when she wore a black sweatshirt with “GOAT” in large white letters: a product of her own fashion line.

With her retirement now imminent, it is certainly time to celebrate her long and phenomenal career, one of the most extraordinary from start to near-finish of any athlete.

A successful Black woman in a predominantly white sport, she has beaten the odds, and talented opponents from multiple generations, across four decades. She has swatted aces and baseline winners, hustled for drop shots, lunged for returns and scrapped back from adversity on and off the court with the sort of sustained tenacity and triumph that only transcendent champions can muster.

As she bids farewell, emotions are rightly running high, yet to unreservedly proclaim her the GOAT (greatest of all time) in women’s tennis is not as straightforward as a short overhead into an open court.

Great will mean different things to different people. Performance is part of it but surely not all of it, and it seems fitting that the first athlete to embrace the GOAT acronym was Muhammad Ali, who billed himself understandably as “the Greatest” and managed some of his business interests through a company named G.O.A.T. Inc. Ali was no doubt a fabulous boxer but also a deeply symbolic figure.

GOAT arguments are passionate and often unresolvable no matter what the sport. In the case of Williams, larger than life herself, it deserves to be a debate, not a processional.

Though they are likely to be inconclusive, there are legitimate reasons to lean toward one of Williams’s predecessors, in particular Martina Navratilova or Steffi Graf, if you don’t want to travel through the mists of time to Margaret Court, who achieved the Grand Slam in 1970 and was the best player of her era.

Tennis history is long for a modern sport: Wimbledon dates to 1877 and the U.S. Championships to 1881. The game and equipment have improved drastically (Navratilova and her friendly rival Chris Evert once played with wooden rackets), and the measures of success have shifted, too.

“It’s really difficult to compare one generation to another,” Williams once said. “Things change — power, technique, technology.”

While there are still formidable obstacles to fair comparisons, and though Williams’s 23 Grand Slam singles titles, an Open-era record and her signature achievement, loom like Mount Rushmore, the title count was not the coin of the realm in earlier eras.

“Nowadays, the Grand Slams are much more revered than they were in my time,” Navratilova said.

Achieving a Grand Slam, by winning all four majors in the same calendar year, was a clear goal after Don Budge became the first to do it in 1938, but a player’s total number of Grand Slam singles titles was not always a major talking point.

“We really weren’t concerned with the number,” Rod Laver, the red-haired Australian who completed Grand Slams twice in singles, in 1962 and 1969, once told me. “I’m not sure I even knew exactly how many I had.” (He had 11 Grand Slam singles titles.)

Wimbledon and the U.S. Championships, now the U.S. Open, have had cachet nearly from the start, but the prestige of the other two Grand Slam tournaments, the Australian Open and the French Open, has fluctuated greatly. International stars regularly skipped them until the 1990s, dissuaded by distance and Christmas-season dates that came with the Australian Open and by more lucrative and sometimes binding commitments.

Players have always had to miss major tournaments because of injury, but champions like Billie Jean King, Navratilova and Evert missed quite a few by choice. So did Court, who retired early, only to reconsider, and later had two pregnancies that interrupted her career.

Court, an imposing net rusher from Australia who dominated her rivalry with King, finished with 24 Grand Slam singles titles and 64 Grand Slam titles overall. Both are records. And though 11 of Court’s major singles titles came in Australia when it had smaller draws and often weaker fields than other majors, 24 is still the number that Williams has been chasing openly and unsuccessfully since taking her own maternity leave in 2017.

Graf, the only player to have won all four majors at least four times, finished with 22 Grand Slam singles titles despite playing about a decade less than Williams. Evert and Navratilova finished with 18 apiece and would surely have won more if they had committed to all the majors like Williams and other contemporary stars.

Evert and Navratilova also had a still-fledgling tour to carry, which meant a busier schedule than today’s biggest stars.

“There was definitely more of a commitment from the WTA standpoint because it was early on and we really had to prove ourselves,” Evert said.

Williams has blown hot and cold on the tour, sometimes skipping its bigger events, including the year-end tour championships.

That lighter schedule probably extended her career but also helps explain why Williams ranks third in total weeks at No. 1 with 319. Graf leads with 377; Navratilova is next with 332. Though Williams finished as year-end No. 1 on five occasions — another significant measure of success — Navratilova did it seven times and Graf a record eight times.

There is also a big disparity in tour singles titles. Williams’s total of 73 puts her fifth on the Open-era career list, far behind Navratilova, who won 167 singles titles and 177 doubles titles in a period when doubles had more cachet than it does now. Navratilova also had a long period of genuine dominance, losing just 14 singles matches in five years from 1984 to 1988. Evert, also a consistent threat, won 157 singles titles; Graf won 107 even though she retired at age 30.

Two other points in Graf’s favor: She had a career winning percentage in singles of 89 percent, the best of the modern GOAT contenders (Williams’s is at 85 percent). Graf is also the only player, male or female, to complete the so-called Golden Slam, winning all four majors and the Olympic singles title in 1988.

Navratilova and Williams both had great runs in majors: Navratilova won six straight in 1983 and 1984; Williams twice won four in a row, the so-called Serena Slams, from 2002 to 2003 and from 2014 to 2015. But neither Navratilova nor Williams could cope with the heavy pressure that came with finishing off the true Grand Slam, falling two matches short.

Williams was stunned in the semifinals of the 2015 U.S. Open by Roberta Vinci, an unseeded Italian whose sliced backhand caused Williams big trouble, but not as much trouble as Williams’s nerves.

“She lost to the Grand Slam more than anything else,” Navratilova said that night, speaking from experience.

What bears remembering is that Williams was 33, retirement age for many a previous champion, and yet she was seemingly still peaking: a tribute to her talent, competitive drive and work with Patrick Mouratoglou, an ambitious Frenchman who became her first formal coach on tour other than her parents, Richard and Oracene.

With Mouratoglou, she chose a racket with a larger head and changed strings to add more spin and develop more margin for error and a more effective Plan B.They also emphasized competing more often week to week to make her sharper at the majors.

Her results and confidence soared. With Mouratoglou, she went on to win 10 more Grand Slam singles titles, all in her 30s. That had no precedent in women’s tennis, and it is one of the strongest arguments for bestowing GOAT status on Williams. She and her older sister Venus changed the game and raised the bar for the opposition, many of whom could not keep up, fading or retiring while the Williamses continued.

Serena Williams was not consistently dominant: She had more dips in form and barren patches than Navratilova, Graf and Evert, and even dropped out of the top 100 in 2006. Arguably, she also lacked a transcendent rivalry, dominating Venus, 7-2, in major finals and playing her in only one final at any level after 2009. Though they had some memorable duels, the rivalry between the sisters was, particularly early on, sometimes as uncomfortable for the viewers as for the siblings.

“Martina had Chrissie; Steffi had Martina and Monica Seles; Court had Billie Jean and Maria Bueno,” said Steve Flink, an American tennis historian and author.

“During Serena’s great years in her 30s, she had no formidable rival to test her to the hilt; that is not her fault but a factor,” Flink added, of the GOAT debate. But Williams, despite her dips, did rule over the best talent available, compiling a 176-72 record against players who have been ranked No. 1. She went 20-2 against her tennis muse Maria Sharapova, a blond Russian who out-earned her in sponsorships for years, which Williams understandably viewed as an injustice in light of her superior résumé.

Williams would agree that she knew how to channel a grudge.

In her essay in Vogue this month announcing her imminent retirement, she wrote: “There were so many matches I won because something made me angry or someone counted me out. That drove me.”

Williams endured and excelled, reaching four Grand Slam singles finals after returning from pregnancy in 2018 despite some in her close circle counseling against a comeback at age 36.

Matching or breaking Court’s record, however flawed, at that late stage might have truly ended the GOAT debate. But Williams has still moved many as a working mother and as a superstar willing to put herself back on the line past her prime.

Williams, unlike Navratilova, one of the first openly gay superstar athletes, has not been a political crusader. She has declined, most recently, to comment on Roe v. Wade being overturned. Her approach has been shaped perhaps by her faith (she is a Jehovah’s Witness) and perhaps because of the risk athletes from earlier generations ran with sponsors for straying outside the lines (“Republicans buy sneakers, too,” Michael Jordan once said).

But Williams’s 14-year boycott of the tournament at Indian Wells, where she and her family were booed and, according to her father, Richard, subjected to racist taunts, spoke louder than words. She has had major outbursts that have cost her some fans. But she has been consistently inspiring, as a champion and a Black woman who roared back after major setbacks in her professional and personal life.

Those include the murder of her half sister Yetunde Price; the separation and divorce of her parents; a blood clot in her lung in 2011 that she said had her on her “death bed”; and another dangerous blood clotting issue during the birth of her daughter, Olympia, in 2017.

Resilience is a mark of greatness, too, and though she may or may not be the greatest in a very strong field, it is certainly one more reason to appreciate her as she walks into the din on Monday night — less than a month from her 41st birthday — to play in one last U.S. Open.