Anthony Pettis fights off doubt as he returns to UFC title picture

— -- There's nothing quite as humbling in combat sports as losing. It's the only weapon that can slice through the shield of bravado that a fighter needs just to step foot inside a cage -- transforming irrational confidence into an infestation of doubt.

And what if said loss means the end of a world title reign and universal claim as one of the sport's pound-for-pound best? And what if it's followed up by two more defeats?

If former UFC lightweight champion Anthony Pettis has one word to describe his journey over the past 18 months, it would be "dark".

"I was depressed. I was like, 'This is what I do. This is what I pride myself on -- [being] the champ of the world. Now I've lost three in a row,'" Pettis told ESPN.com, during a Reebok FightHub event at UFC 205 in New York. "It's a weird place to be at. You find out a lot about yourself when you lose. You find out how good you really are."

Pettis, 29, responded to the losing streak in August by moving down in weight, and he looked spectacular in his featherweight debut by choking out Charles Oliveira. Four months later, a flurry of events conspired to transform his return on Saturday at UFC 206 in Toronto into a very big deal.

Originally the co-main event, Pettis' featherweight bout against red-hot Max Holloway (16-3) was pushed into a headlining role after an injury forced light heavyweight champion Daniel Cormier to withdraw from his rematch against Anthony Johnson. Soon after, Conor McGregor vacated his featherweight title -- by choice or by force, depending upon your perspective -- and suddenly, the Pettis-Holloway fight had the interim featherweight title on the line (with Jose Aldo elevated to undisputed champion).

While Pettis admits the victory over Oliveira "definitely bought some confidence," the recent emotional toll of highs and lows has been heavy.

Pettis (19-5), among the UFC's most dynamic and creative strikers, opened 2015 on the cover of a Wheaties cereal box. A little more than one year later, however, a trio of defeats to Rafael dos Anjos, Eddie Alvarez and Edson Barboza left many doubting whether he would ever be the same.

Among those doubters was Pettis himself.

"You still have that thought in the back of your head -- that feeling of losing," Pettis said. "It haunts you. It's one of the things I hate feeling and I felt it three times in a row. For a whole year I lost. It was a sh---y feeling, but I feel like for now, I have the first win under my belt for a new weight class and a new light. I'm having fun training again and I'm injury free."

Pettis' saving grace throughout his losing streak was that all three defeats came by decision. To that end, he was able to pinpoint a couple of small mistakes that cost him in each fight.

"At this level of the game, it's a game of inches and centimeters," Pettis said. "Anybody can beat anybody on any given day. If you have an off night, there goes the fight.

"I just feel like every time I went out there, there were a couple of small mistakes that cost me the fight. I didn't get knocked out, I didn't get submitted. It was just decisions and output, I think. So we just focused on the output, focused on not letting these guys hold me on the cage [like Alvarez did.]"

Pettis admitted he still questions himself constantly, and says that anyone who claims to be 100 percent confident when entering the Octagon is lying.

"If you're not nervous, you're not ready," he said.

Entering Saturday's fight, Pettis is the betting underdog -- and that's been another positive motivating factor working in his favor. "When you are the underdog, you have nothing to lose," Pettis said. "People expect you to lose. If I go out there with a dominant performance, everyone is going to remember why I was the champ at one point."

The other x-factor for Pettis is knowing he will be the bigger and stronger man after moving down in weight -- and that confidence could be just what he needs to balance out the uncertainty that lingers after his losing streak.

"I'm way stronger. Oliveira is probably the biggest guy in the division [and] when he hit me, I didn't feel it. I wasn't hurt," said Pettis. "Wrestling wise, he couldn't take me down. McGregor dominated [Holloway] from the southpaw stance, and as long as Max can't come forward, he doesn't build that confidence. I've got to be the bigger guy out there and push him around."