The frenetic sports matches in Pelle Cass’ digitally manipulated photographs are a referee’s worst nightmare. Unhinged athletes crowd the field and race around like maniacs, ignoring the rules and generally doing whatever they damn please.

“A friend told me I’m depicting Dionysian chaos,” Cass says. “I like to repeat that, because it captures what I’m going for.”

Based in Brookline, Massachusetts, Cass has been up to this brand of mischief for a while now. He started with street scenes 11 years ago after having a funny thought. “I was looking at the street outside my window and imagined everything that ever passed there—people, bicycles, birds, cars, dinosaurs—piling up,” he says. That inspired his series Selected People, for which he combined multiple photographs of the same street scene taken at different moments, in order to choreograph the random foot traffic he captured into mesmerizing patterns.

Now he does the reverse, unraveling the order and rhythm of sports games into discombobulated madness. Cass started in 2015, after an editor sent him to shoot a basketball game. “It was a revelation—sports, bodies, movement,” he says.

Now every Sunday or Monday, Cass checks athletic event calendars for Boston-area colleges and picks a couple events to photograph. He arrives early to roam the stands, sniffing out the best vantage point for his DSLR. Mounted on a tripod at a fixed angle, it will fire up to 5,000 times over the course of a game, the vibrations shaking the lens so much that the focus sometimes goes out of whack.

Back home, the real work begins. Cass pores over the images, getting to know every square inch of the scene—the glass dividers in a hockey rink, the hash markings on a football field, the distracted fans in the stands. He first chooses the most compelling figures, then finds ones that complement them, like a musician picking out harmonies. Sometimes all the data overwhelms him. “You have a bunch of things you want to put in, and you can’t believe it’s ever going to make any sense,” he says.

It takes no less than 40 hours, and as many as 80. Cass works with layers and masks in Photoshop to combine scenes, isolate figures, and correct color. Up to a thousand images go into the most complicated pictures. “People think it’s the most hideously boring thing, but it’s not boring at all,” he says. “I feel like I’m inside a world.”

Lucky for referees, it’s not a world you’re likely to find inside any actual sports arena.

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