Strapping on his skates a couple times every week, Greg Muller leaves the abstract world of math and enters an arena of brute, brawn, and bench-clearing brawls.

This is roller derby.

Muller, a postdoctoral researcher and assistant professor in LSA’s math department, can’t participate as a player—women dominate roller derby, with a few co-ed teams as exceptions—but he volunteers as a referee for the local league, the Ann Arbor Derby Dimes.

Muller sees similarities between math and roller derby. “Unlike chemistry,” he says, “I don’t need a million-dollar government grant to have a big lab to do experiments.” Likewise, private lessons and personal training don’t necessarily give derby athletes a leg up. “Derby provides an opportunity for a lot of people who haven’t had an athletic background, especially women, to compete in a sport on a fairly high level,” Muller says. “Roller derby requires a unique skill set that doesn't necessarily translate easily from other athletic skills. A lot of people who have never done any sport before can put in the time, learn how to skate, and start competing.

“Derby is important and valuable for those reasons, and reffing is my way of helping. You get to see people getting a lot out of it, and it’s fun to be a part of that.”


As a ref, Muller keeps score and calls penalties. “I did a Fermi computation to estimate that I've made roughly 10,000 calls,” he says. Muller, who says he can skate up to 20 miles in a single game, is one of many athletic academics on campus who get a kick out of roller derby—though he’ll be the first to tell you that kicks and elbows count as foul play and are prohibited. But what’s allowed, encouraged, and required is for all players and refs to choose a pseudonym that suits their derby persona. And the tougher the better.

Greg Muller, known on skates as Dr. Math, claims that mathematicians can be more adversarial in lecture halls than roller derby players during competitions (left). To score points, a jammer (upper right, with a helmet star) must shove her way past blockers on the opposing team. One of Muller’s jobs as a ref is to keep track of the jammer and signal her location (lower right).
Photo (left) by Aurélie De Saint Sauveur. Photos (right) by Dave Schrader.

Professor of Anthropology Alaina Lemon plays as KGBeast. Psychology alumna Dawn Espy (M.S. ’15) uses the name Nailer Swift. And a former staff member of LSA’s Residential College, J. T. Sangsland, plays as ShamWOW.

The roller derby and academic worlds sometimes collide in more obvious ways. Former physics postdoc Jillian Bellovary skated as Big Banger and chose her player number to match her name: 13.7 Gyr (gigayears), or 13.7 billion years since the big bang, otherwise known as the age of the universe.

“Because derby is what I do outside of math, I wanted to have my name be as ‘un-mathy’ as possible,” Muller says. “My pick for my derby name was Hard-Boiled Greg.” But it didn’t stick—instead, he goes by Dr. Math. And his jersey number, 1729, is a decidedly “mathy” inside joke. (It’s something called the “taxicab number.”)

Regardless of his name, however, the players call him one of their favorites.

“His patience in answering questions, his unparalleled ability to keep a level head no matter the circumstances, and his understanding of derby as a community contribute to roller derby scores beyond just sending us to the box,” Sangsland (a.k.a. ShamWOW) says about Muller. “He is a superb example of why people find derby to be an important study in community as well as sport.”

Calculated Risks

“I think one of the reasons it was easy to get into roller derby is because it makes a very good counterbalance to my job,” Muller says. “My job involves sitting and thinking and writing—an analytical focus that can be draining in certain ways. Officiating as a ref is a very nice counterbalance. It’s physically engaging and it requires a very different passive, intense focus.

“And I love skating. It provides a good reset, especially if math is going poorly or if I’m just having trouble leaving something behind.”

Players suit up in protective gear—helmets, mouth guards, knee pads, elbow pads, wrist guards—as do referees like Muller, who sometimes get banged up by wayward skaters. “Learning to get hit while skating takes a while,” he says.

“I think I can only recall two broken arms in hundreds of games, and one broken knee cap. And I’ve seen maybe 20 broken ankles—broken ankles are the defining serious injury of derby. But other than that, it’s just bruises for the most part.”


Muller makes time for work and play, but if absolutely pressed to choose between research and refereeing, he’d go with math.

“One of the things that appeals to me about math is the way that it seems to exist outside of all earthly concerns,” he says. “It’s simply ideas that are consequences of other ideas, and the sheer amount of mileage—the fact that we have a whole discipline that has been constantly discovering counterintuitive consequences of various simple assumptions for centuries—is still remarkable.

“Math is something I happily spend most of my time doing, and then derby is something I spend the rest of my time doing.”

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