Itâ€™s early afternoon in Orlando, the hottest time of day on a characteristically sultry Wednesday in Florida, a state famous for its perennially warm, wet, shirt-soaking conditions, which just so happen to be pretty much perfect for playing tennis.
Or so Iâ€™m told.
Iâ€™m standingâ€”sweating, squinting, pantingâ€”at the opposite end of a court from 21-year-old Ulises Blanch, one of the many elite athletes who train here at the USTAâ€™s National Campus. Iâ€™m here to learn about the upper limits of the serve, the most nuanced stroke in tennis and one of Blanchâ€™s specialties. I tell him Iâ€™m ready. He toes the baseline, lobs the ball into the air, and sends it bolting past me. â€œOne hundred thirty-one,â€� says the speed-tracking system. From across the court I see Blanch grin. Sadistically, I think. Itâ€™s his seventh serve, and his seventh ace.
Blanch possesses a tremendous serve, yet it remains far from the most powerful. Itâ€™s been clocked at 138 miles per hour, which, thirty years ago, would have put him in the running for the biggest hitter in all of tennis. But serve speeds at the professional level have been climbing for decades. The 1990s saw the first official serves in the 140s. By the early 2000s, they were in the 150s. The fastest serve ever recorded came in 2012, when Australian Sam Groth was measured walloping a ball at 163.7 mph. But the Association of Tennis Professionals doesnâ€™t recognize Grothâ€™s serve, because he delivered it at a challenger event, where, according to an ATP spokesperson, serve-speed guns donâ€™t adhere to the same standards as the ones used in tournament play. The fastest serve recognized by the ATP was delivered at 2016â€™s Davis Cup by American John Isner, at a speed of 157 mph.
â€œThere are three big factors in optimizing for speed,â€� says physiologist Steve Kovacs, an expert in serve mechanics. â€œTechnique, technology, and height.â€� The sportâ€™s latest generation of athletes, he says, have pushed the limits of all three.
A former tennis pro himself, Kovacs works with some of the best players on Earth to help them wring as much power as possible from their serves. The technical elements of a stellar stroke, he says, are well understood. You need strength, obviously, but flexibility is equally importantâ€”particularly in the upper body.
During a serve, the majority of a playerâ€™s power originates in their legs, but conveying that power through the body and into the racquet requires stockpiling additional energy in their hips, lumbar, and shoulders, by rotating all three elements in sequence as the ball rises into the air. Tennis types call that rotation coiling. A big serve requires a limber, practiced playerâ€”someone strong and loose enough to twist their torso taught like a rubber band and uncoil themselves a fraction of a second later, with timing so precise that it not only translates the energy from their legs, but augments it.
Hard hitters like Blanch excel at storing and releasing energy throughout their bodies in this way. But theyâ€™re also working with more power, in general. While a typical amateur might produce between 700 and 900 Newtons of ground force with their legs, Kovacs says the most propulsive pros can generate upwards of 1500.
There was a time when tapping into that kind of power on the court was risky. With older, wooden racquets, which dominated the game of tennis for much of the 20th Century, serving too hard significantly increased your odds of overshooting, sending the ball out of bounds.
But in the mid-1970s, manufacturers began blending carbon fiber and resin to produce racquets with bigger heads. The surface area of your typical racquet increased from 70 square inches to well over 100. That expanded the racquetâ€™s sweet spot, which made the game easier for amateurs. But the pros didnâ€™t need a bigger sweet spot. For them, larger, modern racquets have had a different effect: The ability to put more top-spin on the ball. Thanks to a phenomenon known as the Magnus effect, a ball with more top-spin dives toward the court at a sharper angle once itâ€™s cleared the net. Putting more spin on their serves allowed players to lower their risk of launching the ball beyond the bounds of the service box when they hit harder. The result: more powerful play and faster servesâ€”especially for bigger, stronger players.
Today, the hardest hitters in tennis are all tall. Blame physics. â€œIf youâ€™re tall, it means you’ve got longer levers, so you can store energy over a greater amount of time and that allows you to summate your forces over a greater distance,â€� Kovacs says. The spindliest of players have an even greater advantage: â€œAnyone under about 6-foot-7 is still hitting up on their serve.â€� But above that height, a player can reach high enough to actually strike the ball down at their opponent. â€œIf you’re hitting up on the serve, you’re fighting gravity. If you’re hitting down, gravityâ€™s helping you.â€�
Not surprisingly, the five fastest serves ever recorded were pommeled by players 6-foot-4 or bigger. John Isner, who delivered the fastest serve recognized by the ATP, is 6-foot-10. Ivo KarloviÄ‡, who held the record before Isner, is 6-foot-11. But while serve speeds rose steadily throughout the â€™80s, â€™90s, and early 2000s, improvements in the past decade have grown less consistent and more incremental. Kovacs says that one reason for the plateau is that Isner and Karlovic have been playing for a long time, and up-and-coming players have yet to contend with their records.
Whether any of them ever will remains to be seen. Not that there arenâ€™t prospects: American Reilly Opelkaâ€™s serve has been clocked at 145 mph, and heâ€™s only 21. His secret? â€œGood coaching, good mechanics,â€� he says. â€œAlso, being seven-foot helps.â€�
But Opelka says that if the current speed record ever does fall, conditions might play as great a roll as height, technique, and equipment. The fastest serves happen at high elevations, and in hot, muggy climates. (Air density decreases as altitude, temperature, and humidity increase, which reduces drag.) â€œHonestly, that’s why John Isner’s been so successful in Atlanta,â€� Opelka saysâ€“ because his serve, which is already huge, â€œis even more enhanced there.â€�
And yet, players donâ€™t seem to place as much stock in speed as you might think. â€œItâ€™s overvalued,â€� Opelka says. â€œNobody at the tour level pays attention to it.â€� Instead, he says, players gossip about one anotherâ€™s tendencies. â€œThe talk in the locker room before a match, between friends, will be like, â€˜This guy loves his slice serveâ€“last time I played him, every big point, or under pressure, he was hitting his slider.â€™”
Blanch agrees: Speed isnâ€™t everything. Back in Orlando, weâ€™re chatting at the net when he tells me he only recently learned how fast he was capable of serving; his coaches used to hide it from him, so he wouldnâ€™t fixate on it. â€œIâ€™m actually working more on placement these days,â€� he says with a shrug.
Easy for him to say. Even in Orlandoâ€™s hot, humid, speed-friendly conditions, the fastest serve I could manage was 77 mph. I blame my height.
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