Have NHL players maxed out the slap shot? The science behind the speed

Thirty years ago, the average PGA golfer drove the ball 261.84 yards. Davis Love III was the longest hitter at 283.8 yards.

In 2024, the average distance is 300.9 yards, with Cameron Champ leading the way at a whopping 323.3 yards. Technological advances for both clubs and golf balls — combined with a greater focus on fitness — have turned 7,000-yard tracks into pitch-and-putts for the world’s best golfers.

Thirty years ago, Al Iafrate won the NHL’s hardest shot competition at the All-Star skills competition with a 102.7 mph blast, down from his 105.2 a year before.

At the 2024 All-Star weekend, Cale Makar won with a slap shot of 102.5 mph. Utah’s Michael Kesselring and the Buffalo Sabres’ Tage Thompson recently had blasts of 103.77 mph and 104.69 mph, respectively — the only two 100 mph clappers in the league this season. Last season, the 10 biggest bombers combined for 26 shots at or above 100 mph, with the Winnipeg Jets’ Colin Miller topping out at 102.59.

What gives? Iafrate was using an old-school wooden stick. Makar, Kesselring, Thompson, Miller and everyone else in the league is using a custom composite stick, designed to their exact body and mechanical specifications to generate maximum force. Yet the numbers are comparable. There might be more big shooters in the league — tracking data in the NHL only dates back to the 2021-22 season, so we’ll never know for sure — but they’re not really raising the bar by much. Certainly not to the degree that golfers are. Or tennis players are, for that matter.

In fact, it’s more akin to baseball, in which pitchers seem to have reached the limit of human capability at about 105 mph. More and more pitchers throw hard every year — 203 pitchers averaged a four-seam fastball of 95 mph or more this season, up from 123 just seven years ago — but the ceiling isn’t budging. Since Aroldis Chapman hit a record 105.8 mph back in 2010, only Ben Joyce and Jordan Hicks have touched 105, and only once each (Chapman did it nine times). Of course, pitchers aren’t using any equipment. It’s just muscle and mechanics. The human body can only do so much, no matter how feverishly you exercise, no matter how impeccable your nutritional habits are.

Hockey’s different, right? Shouldn’t there be 110 mph shots by now? Or 120, for that matter? Shouldn’t we be talking about scaling back the technology to preserve the integrity of the game, the way the golf world always is? Like every other sport, hockey players keep getting bigger and stronger. But the low-100s remains the gold standard for shot speed.

It begs two questions: Have we reached the ceiling of what a slap shot can be? And why?

“There’s always a limit,” said Detroit Red Wings defenseman Moritz Seider, who has reached 95.54 mph this season, in the league’s 91st percentile. “The human factor only allows you to do so much. And there does come a point where we’re not superhuman.”

Alain Haché knows a thing or two about high-speed projectiles. The experimental physicist and University of Moncton professor seemed to defy the very laws of physics in 2002 when he and one of his students sent a pulse of radiation 120 meters at superluminal speed — that’s faster than the speed of light. But Haché is a hockey nerd, too, the author of two books on the science behind the sport. It makes him uniquely qualified to address such an esoteric topic.

He believes the plateauing speeds of NHL slap shots means that we might have reached our technological limit when it comes to hockey sticks. Iafrate and Al MacInnis and Bobby Hull were physical freaks in the wooden-stick days. All the composites have done is let the rest of the league catch up to them.

“What it means probably is the limitation is no longer the stick itself,” Haché said. “Hockey sticks are pretty efficient already.”

A slap shot is pretty simple from a physics standpoint. When a player rears back and fires, he doesn’t aim for the puck, but rather a foot or so behind the puck. When the stick hits the ice, it flexes, or bends. By flexing the stick, a player is storing potential energy into the stick. When the stick unbends and whips back around, it’s turning that potential energy into kinetic energy, sending the puck on its way.

Energy is always lost in the bending and unbending of the stick, Haché said. A perfectly elastic stick would convert 100 percent of a player’s potential energy into kinetic energy, but modern sticks are pretty close. Haché estimated that modern composites convert “maybe 90 percent.”

“So if you improve your stick (even further), you’re not going to gain a lot,” he said. “You’re not going to double the amount of energy you can transfer. So the energy becomes limited by the player.”

In Iafrate’s and MacInnis’ day, the wooden sticks could flex only so much, and there wasn’t any significant variety from twig to twig.

These days, players have all sorts of options with composite sticks. A stick’s flex — or “whippiness,” in the players’ parlance — is assigned a number. A number above 100 is stiffer, a number below 100 is “whippier.”

Zdeno Chara, a nearly 7-foot-tall giant who holds the record for hardest shot in an NHL skills competition at 108.8 mph, used a famously stiff stick. Alex Ovechkin, on the verge of becoming the league’s all-time leading goal scorer largely on the strength of his cannonading one-timer slap shot, uses an extra whippy stick, in the mid-to-upper-70s. Connor Bedard, who doesn’t have the physical stature of either of those players, uses a super-whippy stick in the low-70s. Whatever suits the player’s mechanics best.

Chicago’s Connor Bedard uses a particularly “whippy” stick, with a flex in the low-70s. (Chris Tanouye / Freestyle Photography / Getty Images)

Naturally, there’s more to it than that, depending on how deep into the scientific weeds you want to get. There’s the “bounce effect,” which means a shot will have more velocity if the puck is moving toward the player at speed when he hits it — think of big Aaron Judge squaring up a 100 mph fastball and imagine the exit velocity. Judge wouldn’t be able to hit a ball off a tee nearly as far, or as fast. It’s not a one-for-one factor because it’s not a perfectly elastic collision; if a 60 mph pass from behind the net is one-timed back toward the net, the shooter won’t get an additional 60 mph on his shot. But he will get a bump.

Now if the player is carrying the puck up the ice at speed and manages to get off a slapper on the rush, he will get all that additional speed. Let’s say Connor McDavid is carrying the puck up ice at 23 mph, his top speed so far this season. If he somehow managed to rip a full slap shot at 83 mph, his top shot velocity this season, while the puck was still moving at 23 mph, his shot would go 106 mph. Easier said than done, but maybe Hall of Famer Marián Hossa was onto something when he would blast those slap shots while racing into the low slot during shootout attempts.

The stick — wood, fiberglass, carbon fiber, aluminum, whatever — is just a tool, though. Technique matters more than anything else. But a little muscle mass doesn’t hurt.

“The power comes entirely from the player,” Haché said. “He will rotate his body. He will time the slap shot so that he can put as much flex as he can in the stick.”

That’s why San Jose defenseman Jake Walman says his shots are harder and heavier earlier in the season, while he still has all the muscle he added over the summer. Players typically lose much of their bulk over the course of the grueling season, as weight-lifting takes a back seat to the endless cardio they’re doing night after night. Their shots can fade along with their weight.

But while behemoths such as Chara and Shea Weber (who nearly caught Chara with a 108.5 at the 2015 All-Star weekend) and the 6-6 Thompson have an inherent advantage, size isn’t everything. Timing is crucial. Pick the puck clean instead of hitting the ice first and the stick won’t flex and the puck will flutter weakly. Hit too far behind the puck and most of the kinetic energy will be spent before the blade even gets to the puck.

“Everyone shoots different, but there are certain things you have to do in order to have a hard shot,” said Chicago’s Seth Jones, who topped out at 97.97 mph last season. “You see small guys have hard shots all the time. You don’t need to be 220 pounds and 6-3 to have a hard shot. And the flex is whatever you’re comfortable with. Some guys shoot harder with (a) 100 flex, some guys shoot even harder with a 75. There’s no one way to do it.”

Zdeno Chara unleashes a 108.8 mph slap shot at the NHL’s 2012 hardest shot competition in Ottawa. (Bruce Bennett / Getty Images)

Power in one sport doesn’t necessarily mean power in the other. Walman’s best golf drives go a relatively modest 270 yards down the middle.

But oh, man, can Walman spin the ball.

“I’m hitting down on it pretty hard,” he said.

The Sharks defenseman blasted a slapper 101.6 mph last year in Vancouver when he was with the Detroit Red Wings. This year, he’s topped out at 94.93 mph. And it’s the same body mechanics that allow him to put so much backspin into a 9-iron that allow him to so consistently hit a hockey puck really hard — the way he rears back and opens up his upper body, the way he transfers nearly all the weight into his front foot with vicious body torque, the way he leans into the stick to create all that flex as he hits the ice six to 12 inches behind the puck, the way he follows through with all of his weight moving forward.

“You’re leaning over way more in hockey than in golf,” he said. “I’m bent over, all my power is generating into that one spot in front. … I’m leaning so far over the puck that all my weight is going down into the puck.”

Walman’s always had a big shot, even when he didn’t have the right tools. He said he was pretty much the last kid in youth hockey to play with a wooden stick. His teammates chirped him for it, and his coaches “gave my mom and dad heck” for not buying him a composite stick. But even at a young age, Walman was able to bring out the flex in the wood and launch missiles all day. To this day, he still wonders which kind of stick is really more powerful when leveraged perfectly.

“I’d say the first 50 percent is everything that you do — the power you’re generating, leaning into it,” Walman said. “And then the stick takes over after that. The second half is the technology.”

So while Haché thinks sticks might be approaching the point of perfection, players aren’t so sure. Jones, for one, was skeptical when asked if the NHL had hit the ceiling.

“It depends on where the technology can go,” Jones said. “Athletes are developing every year, we’re getting faster and stronger and bigger, but it’s not just the human body. It’s a little different than pitching, where it’s just you and your arm and the ball. Here, we’re using equipment. Right now, it seems like it maxed out with how light and strong sticks are with the carbon fiber. But who knows in 10 years where the hell technology can be?”

There’s another question that needs to be addressed here: Does any of this even matter?

While MLB teams have high-tech “pitch labs” and huge staffs devoted to squeezing every last bit of velocity and spin out of their pitchers — if a pitcher’s velocity drops a single mile per hour from one start to the next, team medical staffs kick into gear and fan bases go into a panic — NHL players seem a lot less concerned with the science behind the shot.

See puck, hit puck. Puck go fast.

“I honestly have no idea” how the science works, said Edmonton’s Evan Bouchard, who hit 103 in an AHL skills competition.

Most of the biggest shots in the game come from defensemen, and you’ll see them firing off blasts from the point at that night’s starting goalie at the tail end of every morning skate. It’s more of a ritual than a rigorous scientific process, though.

“I just figure the more you do it, the better you get at it,” Bouchard said. “It’s just practice, repetition.”

When told he was in the top 10 percent in the league when it came to shot speed, Seider said: “That’s obviously cool. But that’s not a stat I’ve ever checked.”

See, a 100 mph shot is a great weapon in hockey. But there are several reasons why it’s not the be-all, end-all the way a 100 mph four-seam fastball is.

For one, full-bore slap shots are very difficult to get off in game situations. There’s a reason most of the biggest blasts come from skills competitions with pristine conditions — a free run-up, a stationary puck (the timing is too tricky to risk playing for the aforementioned bounce effect) and no defender. In a game, time and space are often nonexistent.

“The game is just way too fast for taking the time, going all the way to the top and letting one rip,” Seider said. “People are just in your way more. There’s better coverage, opponents have better sticks on you. You hardly ever get off your best slap shot in an actual game.”

Another reason it’s not as critical: Harder isn’t always better. Back when the Blackhawks were winning championships, they had big Brent Seabrook blasting shots from the point on the power play. But light-hitting Michal Rozsíval would get his share of power-play time, too. And his wimpy little shots just seemed to have a knack for getting through traffic, hitting the net and creating rebounds.

“It’s hard to get off a big shot nowadays,” Bouchard said. “Sometimes it’s better to throw a quick wrist shot on net and see what happens. It doesn’t always have to be as hard as you can hit it. That’s not always the best shot.”

A big windup also gives a defender an extra split second to throw himself in front of the puck. That said, Jones posited that one big shot that gets very painfully blocked might lead to an open lane later in the game, as a defender thinks twice about stepping in front of the next one.

But even he acknowledged that rarely happens.

“It’s a competitive sport,” Jones said. “You’re still going to see guys laying out in front of shots to win the Stanley Cup, whether it’s 80 miles per hour or 120.”

After all, physics might be able to explain how flex and torque and weight transfer and potential energy all add up to a classic clapper. But there’s no explaining what drives someone to step in front of one.

“No one said we’re smart,” Jones said with a chuckle. “We’re athletes.”

(Illustration: Meech Robinson / The Athletic. Photos: Bruce Bennett, Patrick Smith, Steph Chambers / Getty Images)