Which Rousey will show up for fight against Nunes?

LAS VEGAS — There’s a saying around combat sports that every fighter has a screw loose.

So, the intrigue of today’s UFC 207 main event at T-Mobile Arena is what’s bouncing around the mortal mind of the once invincible Ronda Rousey, and how the results inside the octagon will determine the future of one of the most prominent figures in the sport.

Rousey (12-1) has admitted that she slipped into the darkest of places after her head-kick knockout loss to Holly Holm in November 2015, even contemplating suicide. Scheduling her return against a destructive-punching force in new women’s bantamweight champion Amanda Nunes of Brazil is the most telling test possible of how well Rousey has climbed from those depths.

Nunes (13-4), who trains in Coconut Creek, draws inspiration from the expected pay-per-view audience of more than 1 million that will watch her one fight after she landed 40 strikes on Miesha Tate before submitting her by chokehold in the first round of the UFC 200 main event in July.

The Westgate Superbook in Las Vegas has Rousey listed at almost a

favorite, a sharp drop from the double-digit odds her foes confronted two years ago amid talk of her invincibility.

“Why is Rousey favored? Reputation,” Westgate race and sports book director Jay Kornegay said. “It’s a tough fight to handicap because of what she’s gone through over the past year. I’m not exactly sure where her head is these days, but prior to (Holm), she was dominating, and you have to factor that in.

“Hindsight will tell us if she needed that break, or if she’s totally lost it.”

Although Rousey has turned in a phenomenal training camp, according to her trainer, she has given little insight into her mental state.

Rousey, 29, convinced the UFC to grant her unprecedented permission to skip all pre-fight and fight-week media obligations except for a mandatory official morning weigh-in before cameras and a later public session before fans.

Rousey was such a good UFC company person that she would not only take 30 extra minutes after a news conference to repeat what she was thinking after her many first-round victories. She also would find a way to add a personal compliment to her interviewers.

And she displayed such genuine compassion and kindness. She once took the time to write by hand an extended letter of sympathy to a photographer after learning that his dog had died.

Have the effects of the Holm loss erased or diminished that?

Has Rousey tried to convince herself that the distractions of media obligations created the Holm debacle?

What matters most now is the fight, a return to the closed door of the octagon where, 13 months ago, Holm pulled back the curtain on Oz.

Inside there, Rousey will be alone with only her thoughts and Nunes.