Correction: A previous version of this story quoted Mayweather saying he is in his 30s.


UFC PResident Dana White said he expects to see Conor McGregor “turning it into a fight, roughing Floyd up.” (John Locher/Associated Press)

The odds might not be favorable and those with degrees in the so-called sweet science might be shaking their heads, but here’s what Conor McGregor has when he steps inside the ring Saturday: a puncher’s chance. Unfortunately for the UFC star, that might be the extent of his prospects against one of the best boxers of all time.

To win on Saturday in the much-hyped, much-derided showdown against Floyd Mayweather Jr., McGregor seems to know it’s knockout or nothing.

“Part of me kind of wants to show some skill and to dismantle him that way,” he said last week, predicting a second-round knockout. “But I do not see it.”

How daunting is that challenge? McGregor doesn’t seem fazed, but Mayweather has never been floored by a punch in 49 professional fights and it isn’t often that he has even been hurt. If the fight goes to the scorecards — which is a good possibility considering Mayweather hasn’t knocked out anyone since 2011 — McGregor might have to find solace in his life-changing payday.

“I don’t see him outpointing Floyd in a boxing match,” said Dana White, the UFC president. “I see him getting in, turning it into a fight, roughing Floyd up.”

While Mayweather has suggested he might be the aggressor, most fight experts don’t foresee him suddenly tearing up a winning blueprint. He will use the full ring, he will counterpunch, and he will lull McGregor into making mistakes.

With limited boxing training, McGregor will likely try to take the fight to Mayweather and overpower his more-seasoned opponent when opportunities arise, particularly in clutching situations — in other words, a plan like so many foes who have come and gone. Even those who had some success with an aggressive strategy — Jose Luis Castillo and Marcos Maidana, namely — still ended up on the losing side against Mayweather.

“Listen, he’s not a boxer. At the end of the day, Conor McGregor is a fighter, not a boxer,” White said. “In a 12-round fight, Conor McGregor, who is the bigger, younger, stronger guy, needs to hit him in a hurry.”

Even if grappling is off the table, McGregor could send an early message when the two fighters clinch and might be able to display his strength and get in Mayweather’s head. McGregor said the bout for Mayweather will “feel like he’s wrestling a bear when we tie up for the first time.”

“What a human does under stress and fear, no matter what skill set they possess, we grab,” he said. “That’s just a human reaction: We grab and hold. . . . When he tries to grab and hold me, he’s not just grabbing and holding a boxer, he’s grabbing and holding a serious specialist in the clinch. . . . He just does not understand what he’s in for.”

While McGregor supporters like to point out that a southpaw presents unique challenges for Mayweather, the veteran boxer, a world champ in five weight divisions, has still disposed of every left-handed foe he has faced, from Zab Judah to Manny Pacquiao.

White likes to say that McGregor hits like a truck, but that only matters if he can land a shot. Mayweather might be the best defensive fighter of all time and has taken very little punishment over the course of 49 fights. Mayweather has officially only been knocked down once — against Carlos Hernandez in 2001 when he hurt his hand landing a punch and briefly touched the canvas with it.

Even Pacquaio, considered one of the best pound-for-pound fighters of his era, averaged fewer than seven clean shots per round (not even one-quarter of his average) against Mayweather in 2015. He landed barely one in five punches he threw that night.

But for the UFC star, might that be enough?

“In a 12-round fight, is Conor ever going to hit him once? I believe he will,” White said. “I believe he’ll hit him more than once. And we’ll see what happens when Floyd gets hit.”

The fight is presumed to be such a lopsided affair that the Mayweather camp has been thrust into the unusual position of talking up McGregor’s chances, highlighting his strengths and noting Mayweather’s own weaknesses.

“If you really look at it on paper, everything leans to him,” Mayweather said recently. “I’m saying on paper. He’s bigger. He has a 74-inch reach; I have a 72-inch reach. I’m inactive; he’s active. Youth is on his side. He’s in his 20s; I’m in my 40s.”

They’ve also stressed the unpredictability inherent in any fight. What if McGregor does slip in a punch and Mayweather’s eye swells shut? What if Mayweather injures his hand early and has to essentially fight one-handed?

“I’m never going to say a guy don’t ever have a chance,” said Leonard Ellerbe, chief executive of Mayweather Promotions. “As long as he got two hands, anything can happen.”

While many might knock McGregor’s ring experience, he adjusted his training to account for the challenges boxing poses. McGregor is accustomed to MMA’s five five-minute rounds — 25 minutes total — and on Saturday will need to be prepared to box 12 three-minute rounds — 36 total minutes. Only two of McGregor’s 24 MMA fights have lasted beyond the second round and only one has gone the full five. So he focused his training more on conditioning, sparring 12 full rounds at a time and even working out in an altitude chamber that mimics conditions at 13,000 feet. “I feel absolutely amazing,” he said last week.

“There’s no way in hell that I am not ready to fight in the deepest of trenches in this contest,” he said. “The training sessions and the practice that we’ve been putting in has been to hell and back. So we are prepared for every possible outcome.”

Regardless, he doesn’t seem to think a boxing round is quite as draining as what he’s used to. “You’re not broken down,” McGregor said. “There’s no scrambles, no lifting the leg. No 360 spins.”

To sneak in that knockout punch, McGregor is also hoping to rely a bit on unpredictability. He has shown only flashes of his boxing skills in the MMA octagon and in recent months has teased the fighting public with some video clips — mostly mundane and unimpressive — from his training sessions.

“I know every [thing] he throws,” McGregor said. “I know what to expect. I’ve seen it before. He does the same stuff over and over again. . . . For him, he knows nothing. He knows absolute nothing about the way I’m going to approach this fight and the way I’m going to come at him. That’s a beautiful position to be in.”

Regardless, despite pre-fight hype designed to sell the pay-per-view, Mayweather has never been worried stepping into a ring. He has generally felt assured of the two things that matter to him most: a guaranteed paycheck and another victory.

“Nobody knows that squared circle like me,” Mayweather said. “I know angles. I know where to touch you at. I know what you don’t like. I don’t have to watch your tapes. That’s something I’m blessed with.”