Sports

What an Astrophysicist Sees in Basketball That You Don’t

A scientist who closely watches NBA defenses describes how they remind him of a cosmic dance.

A player in a jersey reading "Pioneers" going up for a layup or grabbing a rebound his head and body illustrated as stars in a night sky.
All players are stars, really. Photo illustration by Slate. Photos by Logan Weaver/Unsplash, Adrian Pelletier/Unsplash, and Markus Spiske/Unsplash.

This excerpt is adapted with permission from the new book How to Watch Basketball Like a Genius: What Game Designers, Economists, Ballet Choreographers, and Theoretical Astrophysicists Reveal About the Greatest Game on Earth by Nick Greene published by Abrams Press © 2021.

What does great basketball defense look like? The question is surprisingly difficult to answer. Individual defensive success can be easy to spot—Natasha Howard swatting a layup into the stands or Kawhi Leonard ripping the ball from a dribbler’s grasp like a nasty older sibling—but effective team defense often manifests itself in the things you don’t see. Players can’t penetrate with the ball. Passes get exchanged around the perimeter without purpose. Lanes are clogged, expected geometries denied.

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With all the other action occurring on the court, these defensive subtleties are easy to miss. To help, I sought out an expert in a field that requires looking closely at what’s invisible.

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Bronson Messer specializes in seeing the nigh unseeable. He is a computational and theoretical astrophysicist at Oak Ridge National Laboratory in Tennessee, meaning he tries to make sense of what is happening at the farthest reaches of the universe.

“I’m wholly dependent upon visualization,” he tells me. “Of course I have to know quantitative data. I need to know exactly what the temperature of an exploding star is at some point, and I need to know exactly how many neutrinos are being emitted per second and that kind of stuff. But to understand what is actually going on, to understand the physics of what is actually happening, we rely on very sophisticated visualizations of what’s going on inside the boiling heart of an exploding star.”

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When I first got in touch with Messer, in January 2020, he had his eye on Betelgeuse, a big red ball of gas sitting on the shoulder of Orion. “It’s the star closest to us that’s most likely to go supernova,” he said. “It’s making the news right now because it has dimmed precipitously over the last month. Used to be you could go out and you could immediately see that it was red and it looked large. Now, if you go out tonight and look, you’ll have a hard time seeing it because it has dimmed.” When stars dim like this, it means that a cosmos-altering boom might be imminent. Betelgeuse is the 10th-brightest star in our sky, and its potential supernova is a huge deal. “It’s not going to go tonight, probably, but it could. But when it does explode, Betelgeuse will be brighter than the full moon for a few months, and it will be daylight-visible for weeks.”

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In order to understand what’s happening inside a star 770 light-years (4,526,541,537,351,377.952755906 miles) away, Messer relies on what he calls “physical intuition,” which he describes as the ability to craft a phenomenological and narrative understanding of the otherwise unknowable. “Physical intuition is something that is drilled into the heads of grad students when they’re training,” he says. “One of your primary responsibilities as a grad student is to, quote, ‘develop your physical intuition.’ And to me it wasn’t that hard of a concept because I was such a big sports-head when I was a kid. It made perfect sense to me. You have to develop experience seeing patterns over and over again so you can somehow figure out what’s going on.”

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Thanks to years of playing and watching basketball, Messer is confident in his physical intuition as it pertains to hoops. “You can see a pick-and-roll about to happen,” he says. “You know what the vocabulary that’s going to build up to the play is about. But on defense, you have to be thinking instead of the next sort of move, you have to be thinking two moves in advance. I think that’s kind of hard for people to grok unless they’ve had empirical experience.”

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After running these rhythms and patterns through his brain—his “wetware,” as he calls it—Messer managed to produce a visual analogue that has stuck with him. “The best defense, I always think, looks like an iridescent turtle shell.”

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Can you picture it, this magical, shimmering, reptile? No? Think about a possession in which the defense creates a sort of force field around the perimeter. That’s Messer’s shell. “People move in these epicycles, these little convective cells that make little circles around at the edges, and it pushes everybody out.”

Broadly speaking, basketball teams have two general defensive strategies they can run: man-to-man, where each player is responsible for guarding a single opponent, and zone, wherein they are tasked with defending a specific area of the floor. Nowadays, most professional teams will play a mix of the two styles that, to at least one theoretical astrophysicist, looks like an iridescent turtle shell.

“Imagine one guy with the ball,” Messer says. “He probes, stepping into the top of the key with it to see if he can drive or not. He’s either going to drive and shoot or he’s going to drive and dish. The double-team comes, a guy peels off and goes to the center. They make these convective cells, little churnings that are little circles, two people running in a circle over and over again. A tight circle, but still a circle. It pushes all the action to the edge. Or, the two guards pinching at the top of a zone defense and not letting that guy drive into the center of the lane. They peel off and make a little circle when they do that.” He pauses to give his metaphor some thought. “Perhaps it’s more of a snapping turtle.”

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Messer has a soft spot for defense. As a kid he was always the “big palooka” tasked with protecting the middle of the floor. Much like his current job observing the cosmos, that gave him an opportunity to watch and learn how bodies move through space. “Even though our star [the sun] is a single star, most of the stars in the universe are in binaries or multiple systems,” he tells me. “They dance around each other. There’s certainly a dance that comes along with basketball offenses and basketball defenses and what they move like. This happens more in the NBA now that you don’t have to play only man-to-man. There is a rhythm to a defense.”

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Keeping track of this rhythmic dance isn’t always easy. “Every offensive move has a counter, and every defensive counter has a counter-counter,” Messer says. Basketball becomes a guessing game.

Messer is a genius who gets to work with the fastest computer in the world, yet he only managed to get one Final Four team correct in his 2019 March Madness bracket. His picks were so bad, the Knoxville News Sentinel wrote a story about it. (Headline: “Busted NCAA bracket? Don’t worry, even a rocket scientist’s predictions aren’t perfect.”)

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Messer can laugh about it, though. He’s used to dealing with the volatility of the universe. For an example, look up at the night sky. Betelgeuse is still there, fully intact.

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It had been a few months since our chat about the iridescent turtle shell, and I wanted to check back in with Messer to see how the red giant was doing. “It’s brightened back up,” he explains. “It got dimmer and dimmer and dimmer for many months, and it’s turned around. When it got really, really dim, it got a little scary. It’s not supposed to get that dim. It was a remarkable event.”

To the best of Messer’s knowledge, Betelgeuse was not primed to go supernova, and an explosion is not actually imminent. It was just one supergiant misunderstanding.

“It’s almost back to its usual peak brightness,” he says. “It probably was an episode of dust ejection. It ejected some dust and that dust obscured it for a while. It’s become diffuse enough that it can shine through again.” Betelgeuse, at least from our perspective, keeps on churning.

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“It totally pump-faked us,” he laughs. “It was quite a pump-fake.”

How to Watch Basketball Like a Genius by Nick Greene Book Jacket, showing "The Thinker" with a basketball as its head.
Abrams Press
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