"'I don’t fight for free,' she said. 'Don’t worry.'”

In M.M.A., more than in most sports, athletes must be promoters, too. Rousey is smart enough to know that one of her promotional assets is the way she looks—she has appeared on the cover of not only ESPN the Magazine but also Maxim, which called her “Badass & Blonde,” and photographed her in a garment that seemed highly unsuitable for combat. Of course, this asset can be a liability, too, especially for a female fighter seeking the same respect given her male counterparts. Rousey is five feet six, and even someone who didn’t recognize her might guess, glancing at her powerful arms and shoulders, that she was some sort of athlete. But while some fighters strike an impassive pose, shrugging off questions the way they shrug off the dangers of the cage, Rousey is nothing if not expressive. She smiles often, squinting so tightly that her eyes disappear. She cries easily, a girlhood habit she never outgrew. And before each fight she glares at her opponent as if she were getting ready to put a permanent end to a lifelong feud. After the fight, she is all smiles again, and usually unblemished. “Somebody told me once that it’s the pretty fighters you have to watch out for,” she says, slyly. “If someone’s all gnarled and mangled up, obviously they’ve been getting hit a lot.”

Rousey speaks more or less the way she fights: in measured provocations, never committing herself to a gambit that she can’t defend. When KTLA cut to her in the gym, she talked politely about McMann’s wrestling achievements, and about their parallel careers: McMann won a silver medal in wrestling at the Athens Olympics, while Rousey took bronze in judo at Beijing. The goal, after all, was to persuade fans to pay $54.99 to watch the two women fight, live from Las Vegas, on pay-per-view. But once the cameras left she assessed her chances more candidly. She predicted that McMann would fall back on her old wrestling moves for fear of Rousey’s brutal arm bar. “I don’t think that this matches up well for her,” she said. “I wouldn’t say that in a pre-fight interview, and I haven’t. Because it doesn’t make sense in order to sell it. I need people to doubt me.” She laughed. “And, besides, these guys”—she nodded toward Tarverdyan and his assistants—“put large sums of money on me winning, and they always get shitty odds. So I want to help them out.” She looked up. “Edmond, do you know the Vegas odds for this?"

“Three-ninety-five,” he called back. A bettor would have had to lay three hundred and ninety-five dollars on Rousey in order to make a hundred if she won. Still, that meant the oddsmakers were giving McMann a better chance than they had given many of Rousey’s previous opponents.

Read More | "Mean Girl: Why the world’s best female fighter loves to be hated" | Kelefah Sanneh | The New Yorker