Serena Williams described her desire to be “perfect.” “I know perfect doesn’t exist,” she wrote in Vogue earlier this month, announcing her plans to leave professional tennis. “But whatever my perfect was, I never wanted to stop until I got it right.” Williams’s serve — the most elementally sound component of her game — might come as statistically close to perfection as a tennis stroke can get.

This week, fans can appreciate this masterstroke as she plays her last U.S. Open and takes one more crack at tying Margaret Court’s all-time record of 24 Grand Slam titles.

Fluid like water but powerful like a jackhammer, Williams’s serve has underpinned her 23 Grand Slam victories — more than any player in the Open Era. Her dominance began and ended with that signature stroke. The Grand Slam titles came easily when she won an astronomically high percentage of first serve points, harder when her first serve was marginally off.

Williams turned professional in 1995 at age 14, following the lead of her older sister Venus. Unfortunately, the WTA did not start keeping match statistics until 2008, which lops off the first 13 years of her incredible career — a period in which she won six majors. But since 2008, Serena’s monopolization of the serving categories has become all the more apparent.

Williams’s serving dominance made it nearly impossible for opponents to make headway in her service games. If an opponent was lucky enough to get a look at a second serve, they often saw a massive kick serve. By changing the serve’s spin from slice to topspin, she would hamper her opponents’ ability to make a quality return. While Williams isn’t the career leader in the share of second serve points won, she’s still up there, hovering right around 50 percent, which is a mark of excellence in that stat category. Her high win rate on first serves compares favorably with her male counterparts,  greats like Roger Federer at 77 percent, Novak Djokovic at 74 percent and Rafael Nadal at 72 percent.

Her former coach, Patrick Mouratoglou, called Williams’s serve the greatest ever. The statistics certainly suggest that her serve was the best in the women’s game. She averaged 106 mph and recorded the fastest at 128.6 mph in 2013. Williams’s serve speed often exceeded that of her male counterparts. As recently as 2021, her fastest serve at the Australian Open (125.5 mph) equaled Nadal’s fastest at the same tournament and was faster than that of 52 men in the event. 

But more important than possessing raw speed, her serve has been consistent. Over 27 years, she executed a serve with an abidingly reliable motion tens of thousands of times. It’s a tribute to its efficiency that she’s still standing, knees intact, shoulder in one piece.

“Serena has the unique ability to ace with a less than 90 mph slice serve with the same exact motion that she hits a 120 mph serve down the T from the exact position. This makes it virtually impossible for the returner, who can only guess,” said Joseph Oyebog, a former hitting partner to the Williams sisters early in their career.

Williams has attributed her serve’s consistency to the details. In her pre-serve routine, she always bounces the ball five times before first serves and twice before second serves. She never stashes a second ball. Her iconic toss has been studied for its uncannily constant placement — something related to her use of a finger roll. Other powerful servers in the women’s game, like Ana Ivanović, never nailed the consistent toss. Williams’s backswing — neither too long nor short — has always been hitch-free. Her arm extension and footwork have been studied by physicists seeking answers about her serve’s efficiency. Most players use a continental grip on their racket, but she uses an Eastern forehand grip for more power. Her timing achieves the rhythm of a bowhunter: slow, slow, slow, fast.

Reflecting on her fastest, 128.6-mph serve at the 2013 Australian Open, Williams remarked that it was “my fastest that went in. I’ve hit some 150s, but of course, they’re, like, to the sky.” Of course.