By Jason Keidel

When it comes to Conor McGregor against Floyd Mayweather Jr., how do you handicap a fight between fighters who have mastered different arts of fighting? When one man steps into another man’s world, realm and home, it’s hard to measure the advantage or disadvantage. Vegas can nudge the needle of wagering one way or another, but they don’t know any better than we do.

READ MORE: Michigan Matters: Pistons’ Rob Murphy on Helping His Hometown

Even more so, what metric measures each man’s risk? How do you gauge risk and reward beyond the monetary?

Who has more to lose outside the ring? The 28-year-old who’s in his athletic and cultural prime? How will he look if he loses to a veritable geriatric, a man 12 years his senior? Mayweather, on his best day, was hardly a hard puncher; his right hand, as Jimmy Cannon would say, couldn’t crush a grape.

Whose legacy suffers the most with a loss?

McGregor, of course, is still building his empire and legacy as the biggest name in UFC. While Jon “Bones” Jones is widely considered the best fighter in the sport, no one has the cash or cachet McGregor pulls. No one is pining for Jones to fight, say, Anthony Joshua. But Super Bowl quid is being bet on the August 26 bout.

Mayweather’s legacy is secure, as of now. At 49-0 — a fine record that tethers him to Rocky Marciano among mystical boxing records — Mayweather is easily the best boxer this young century, and among the best fighters of any generation.

>>MORE: Commentary from CBS Local Sports Voices

But what if…

READ MORE: Ribs RnB Music Festival Kicks Off This Weekend In Downtown Detroit

What if McGregor, who enters the ring swathed in that puncher’s chance, actually does it? What if he pulls a George Foreman and decks the faster, more refined fighter? What if Mayweather got old over the last year, gets cute or cocky, and lowers his gloves one too many times? What if one of those famed, MMA roundhouse punches hits the mark, somehow lands on the most elusive chin on earth?

Mayweather has been staggered a few times, especially by an aging Shane Mosley, though Mosley was once a truly sublime boxer who’d been training for that moment for 25 years. But suspend some cynicism for a moment and give McGregor a real shot. It’s not impossible that he sneaks a hard punch on Mayweather’s robust mouth.

McGregor, for all his faults and bluster and hubris, has made all the logistical and pugilistic concessions. He swapped the octagon for a ring, traded his feet for fists and must fight more than double the rounds to which he’s accustomed. Call Conor McGregor what you like, but he’s certainly not a coward.

So under perfect conditions and epic advantages, Mayweather cannot lose this fight and consider his record perfect anymore. Even if this fight is not sanctioned by any boxing or UFC entity, it’s still two guys punching each other until one falls or the judges call it.

If McGregor loses, he will be lauded for trying something new, for venturing into a fighting frontier, for taking on the best at an altogether different craft. Some will care about age. But none of them ever had to fight Floyd Mayweather Jr. And this is still a victory for UFC, a sport that has elbowed its way into pop culture and mainstream television. Indeed, there’s no fight among McGregor’s peers that would generate the kind of quid and keen interest we’re seeing in the weeks leading up to this fight.

If Mayweather loses, it’s a disaster, a personal and professional train wreck that will hurl him into eternal retirement, if not into eternal shame. And it will add heft to the argument, right or wrong, that MMA fighters are more skilled than boxers. Mayweather can’t hide behind his age or any technical disadvantages, because he enjoys all of them. His rules, his town, his night.

Mayweather trades on the twin notions that he’s unbeaten and unbeatable. Losing to someone who enters a boxing ring professionally for the first time doesn’t come with a parachute. Mayweather has spent too much time telling us how great he is. And if McGregor hadn’t heard any of Mayweather’s gaseous sermons, surely he heard it on loop while they were on their four-city promotional tour.

It’s his rules, his town, his night. But if Mayweather loses, it’s no longer his world.

MORE NEWS: Judge Says Michigan Gov. Whitmer Won't Have To Testify In Abortion Lawsuit

Jason writes a weekly column for CBS Local Sports. He is a native New Yorker, sans the elitist sensibilities, and believes there’s a world west of the Hudson River. A Yankees devotee and Steelers groupie, he has been scouring the forest of fertile NYC sports sections since the 1970s. He has written over 500 columns for WFAN/CBS NY, and also worked as a freelance writer for Sports Illustrated and Newsday subsidiary amNew York. He made his bones as a boxing writer, occasionally covering fights in Las Vegas, Atlantic City, but mostly inside Madison Square Garden. Follow him on Twitter @JasonKeidel.