With her victory at Wimbledon this past week, Serena Williams cemented her standing as number one in the women’s world tennis rankings (she has twice as many points as No. 2 Maria Sharapova), and she is a win away at the U.S. Open from completing a calendar grand slam—a feat that has not been accomplished since Steffi Graf did it in 1988. Serena Williams is also one win away from tying Steffi Graf’s record of 22 grand slam tennis championships. Many pundits and commentators are saying that Serena Williams should be viewed as one of the greatest athletes of all time—regardless of gender or sport. She should be up there with Michael Jordan, Wayne Gretzky, Tiger Woods, Muhammad Ali and Joe Montana. So with Serena Williams standing on the doorstep of history, we look at six reasons why she should be viewed as one of the greatest athletes and competitors of all time:

6. She Defies Age

At 33 years, 289 days, Serena Williams became the oldest tennis player to win a grand slam singles title in the open era—male or female. She has now won majors in as a teenage (one), in her 20s (12) and continuing into her 30s (eight). In fact, the eight grand slams Serena Williams has won in her 30s is also a record—male or female. And she has an impressive record of 21 wins to just four losses when competing in grand slam finals—another record for either a male or female tennis player. Serena Williams’ performance in grand slam finals has led sportswriters to label her the “greatest closer in sports,” and for good reason. Even scarier, Serena Williams shows no signs of slowing down. There is currently no other woman in professional tennis who is close to her in points, wins or championships.

5. She Has Won Multiple Gold Medals At The Olympics

Serena Williams not only won a gold medal for her individual play at the 2012 Summer Olympics, she has also won three gold medals for doubles tennis at the 2000, 2008 and 2012 Summer Olympic Games. Paired with her sister Venus, Serena Williams has proven to be a strong doubles threat as well as a dominant singles tennis player. In fact, Serena has 13 grand slam doubles titles to go along with her 21 singles grand slam titles—for a combined 34 grand slam trophies. Serena and Venus Williams have won doubles tennis titles at all the major tournaments—the Australian Open, French Open, Wimbledon and the U.S. Open. Put this together with her four Olympic gold medals and you get a clear sense of how dominant Serena Williams has been in the sport of tennis.

4. She Overcame Long Odds To Reach The Top

Like many all-time great athletes, Serena Williams overcame long odds to reach the pinnacle in the often elitist and cloistered world of tennis. Raised in Compton, California, one of the most violent and dangerous neighbourhoods in the United States, Serena Williams was homeschooled by her father, who has also coached her exclusively since she was in ninth grade. Serena Williams was also pulled from the junior tennis circuit as a youngster because of racist remarks and threats made by rival parents of white children. And Serena’s sister Yetunde, was fatally shot to death in Compton, California, in 2003 when Serena Williams was 22 years old and her tennis career was taking off. And in 2011, Serena suffered a pulmonary embolism that almost killed her. Yet despite an unconventional and poor upbringing, as well as tragedy in her family, Serena has beat the odds and gone on to excel in her sport of choice.

3. Her Ranking As The World Number One Tennis Player

Currently, Serena Williams holds the world number one ranking for a woman tennis player, and has since February 18, 2013—more than two calendar years. She was first ranked world number one in 2002 and has reached the top position now on six separate occasions. Serena Williams is the oldest female tennis player ever to be ranked number one in the world. This is a testament to Serena’s dominance on the court. For more than a decade she has commandeered the top spot in women’s tennis and held that spot like no player before her. Serena Williams is also the most recent player, male or female, to have held all four grand slam singles titles simultaneously—in 2002–03 and, again, in 2014-15. And having more than double the points of the second-ranked Maria Sharapova, Serena shows no signs of relinquishing the world number one ranking any time soon.

2. She Has Been The Face Of U.S. Tennis

American men’s tennis has been in a rut since Pete Sampras and Andre Agassi retired from the sport. The last U.S. man to win a grand slam title was Andy Roddick in 2003. In the intervening years, Serena Williams has become the face of U.S. tennis—male or female—and has dominated the sport like no American male ever has. Consider that Serena Williams has more grand slam titles than John McEnroe and Jimmy Connors combined, and you get a sense of her prowess. Serena has also burnished her image in the minds of American tennis fans through numerous endorsements, celebrity events and charitable work. When people in the U.S. think about tennis now, they think of Serena Williams and look to her as the standard bearer for the country’s tennis program.

1. She Transcends The Sport

Think of basketball and the first name that comes to mind is Michael Jordan. Hockey and its Wayne Gretzky. Boxing and Muhammad Ali comes to mind. Golf and it’s natural to think of Tiger Woods. Men’s tennis and the name Roger Federer likely jumps out. And women’s tennis it is Serena Williams. Like all great athletes, Serena Williams transcends her sport. She has dominated and won to the point that she has become synonymous with women’s tennis. She is an icon and a living legend. And while there have been great female players in the past, none have become linked to the sport like Serena Williams. In an age when tennis players are fitter, stronger and better than at any time in the past, Serena Williams has been the dominant force in the sport. And like all legends, she has accomplished everything there is to in her sport. With a win in this year’s U.S. Open, Serena will achieve her last remaining challenge—a calendar grand slam. But win or lose in New York this September, Serena Williams is already the greatest tennis player of all time.