CHATTANOOGA, Tenn. — Late one Saturday evening in June, two men in their 20s stood across from each other, shirtless and swaying, in a mixed martial arts cage in Exhibit Hall B of the Chattanooga Convention Center. The mat was sticky, a dark canvas of blood and foot sweat. Something in the combatants’ eyes made them look both terrifying and terrified, wolflike and rabbitlike at once.
The bout was one of 12 that evening in the B2 Fighting Series 166, an amateur event, and Dr. Danielle Fabry, a primary care physician with a private practice in Nashville, had been hired to make sure no one got seriously hurt. Stationed by the cage door, she had the best seat in the house.
Combat sports run on the excitement of an unstable equilibrium. In a perfectly matched fight, combatants trade blows until the final bell, bringing their bodies as close as possible to their limits. One mistake, though, and it ends violently. This combination of uncertainty and danger has helped transform mixed martial arts over two decades from a siloed obsession, illegal in a number of U.S. states, to a multibillion-dollar industry.