On Saturday night, during the third round of a thrilling U.F.C. bout between Holly Holm, the bantamweight champion, and Miesha Tate, the challenger, one of the announcers broke an unwritten rule. Throughout the battle, which was broadcast on pay-per-view, the commentators had been trying to keep their focus on the two women in the cage, and trying to avoid talking about a certain absent star who cast a shadow over the event. But eventually Mike Goldberg, the play-by-play announcer, couldn’t help himself. As Holm and Tate circled and feinted, he asked, “What is going through the mind of Ronda Rousey right now?” And then both men went uncharacteristically silent for nearly ten seconds—enough time, perhaps, for them to try and fail to think of an answer, and to refocus on the matchup in front of them. Then they changed the subject.

Holm has been a professional fighter for more than fourteen years, and a famous one for less than four months: she became a sports celebrity last November, when she spent six minutes destroying both the body and the myth of Ronda Rousey, a previously unbeaten (and seemingly unbeatable) phenomenon who had emerged as the biggest star in mixed martial arts, or M.M.A. Rousey’s loss might have been, as the commentator Joe Rogan put it, “the greatest-ever upset in U.F.C. history.” Holm, a former boxer, seemed happily dazed to be suddenly living the life of a sports celebrity. Fans wanted a rematch, but Rousey said she needed time to recover from the fight, which ended with Holm delivering a brutal head kick that knocked the champion unconscious. (Not long afterward, Rousey told ESPN that her teeth still ached. “It might be three to six months before I can eat an apple, let alone take an impact,” she said.) And so Holm, not wanting to sit idle indefinitely, secured an appointment with the next most qualified opponent: Tate, who had won four in a row since her last loss, to Rousey.

This seemed like a risky match, not just for Holm but for the U.F.C. itself, which might have preferred to keep Holm intact for the eventual Rousey rematch. Dana White, the organization’s voluble president, claimed to have mixed feelings about Holm’s disinclination to wait for Rousey. “As a fan, I love her attitude,” he said. “As the business side, I absolutely hate it.” If Holm lost to Tate, then a Holm-Rousey rematch would be diminished—it would be a grudge match, but no longer a championship match.

As the fighters were introduced on Saturday night, an onscreen graphic identified Holm as the favorite, at -325, which reflected how much the Rousey victory changed the public perception of Holm, who had only converted from boxing to mixed martial arts a few years ago and who had seemed shaky in her two U.F.C. appearances before she knocked out Rousey. Against Tate, one of Holm’s biggest assets seemed to be her four-inch reach advantage, and as the first round began, she used her fists and feet to keep Tate too far away to threaten her. Then, in the second round, Tate took Holm to the canvas, where Tate had a decided advantage. Immediately, Goldberg started to speculate about the potential implications of a Tate win, aware that it would scramble the established storyline. She was “trying to muddy the waters,” he said.

Sports fans are accustomed to muddy water, as athletes and teams fluctuate game by game, season by season. But combat sports, with their small sample sizes and non-metaphorical displays of dominance and submission, provide an illusion of clarity. Two athletes enter a cage, and often one leaves it in markedly better shape than the other. In her two victories over Tate, Rousey seemed to prove she was definitively better. You got the feeling that Tate could never beat her—and that perhaps no one else could, either. In November, when Holm kicked Rousey to the canvas, fans had to figure out how to synthesize this new data point. Was Holm therefore as great—as invulnerable, even—as we once thought Rousey was? Had Rousey’s invincibility been a myth, the result of a statistically unsound extrapolation from her mere dozen M.M.A. victories? Or was this a fluke—a great fighter, a bad night, an anomalous outcome?

After a brief hibernation, Rousey reappeared, reclaiming her old celebrity, with a few changes. In a typically transfixing and unpredictable interview with Ellen DeGeneres, Rousey remembered the moments after her defeat:

I was in the medical room, and I was down in the corner, I was sitting in the corner and I was like, “What am I, anymore, if I’m not this?” And I was literally sitting there and thinking about killing myself in that exact second. I’m like, “I’m nothing.” I’m like, “What do I do anymore?” and, “No one gives a shit about me anymore without this.” To be honest, I looked up and I saw my man, Travis, was standing there. And I looked up at him and I was just like, “I need to have his babies. I need to stay alive!”

Unlike most M.M.A. fighters, Rousey has plenty of options outside the cage. She has a budding Hollywood career, even though her acting skills are as yet unproven. And in January, she hosted an episode of “Saturday Night Live,” although the writers didn’t quite know how to address the new reality of her athletic career. It’s easier, no doubt, to write jokes for the baddest woman on the planet than to write jokes for the second-best competitor in the U.F.C. bantamweight division.

Holm survived the second round against Tate, although she clearly lost it, and she returned to form in the third and fourth, landing just enough precise punches and kicks to keep Tate away, and to sway the judges. Scorecards are kept secret until the end, but it turns out that, as the fifth and final round began, Tate was behind by one point. (All three judges had been impressed by that second round, giving it to Tate by two points.) If Tate had won the fifth, the result probably would have been a draw, and Holm would have kept her belt; to win the championship, Tate needed to do something extraordinary, which seemed unlikely. As the round passed its midpoint, some attendees began to boo, protesting the predictability. Goldberg said, “Both women about two minutes away from going the distance for the first time in a championship fight.”