Bookmakers paying out ahead of time is an old PR trick, in this instance presumingly to cover up the miserly and frankly logic-defying odds on the brash Irishman to stun the world at the T-Mobile Arena in Las Vegas.
Mayweather is currently around a 3/1 on favourite, making him, according to oddsmakers, ten times less likely to beat McGregor than he was to defeat his last opponent, two-time world champion Andre Berto.
Indeed, of Mayweather’s last ten opponents, all but Ricky Hatton and Manny Pacquaio, two of the greatest boxers in modern times, were greater underdogs than McGregor.
Ahead of facing Mayweather, Hatton and Pacquaio had boasted 100 professional boxing wins between them, compared to the grand total of zero victories McGregor has under Queensbury rules.
Amateur pedigree is much harder to define, but UFC Lightweight champion McGregor seems to have little of that going for him in any case. McGregor is one of the better boxers in the sport of Mixed Martial Arts (MMA) but as a counter-puncher, he will find opportunities like the left hook he landed on Jose Aldo and propelled him to super-stardom as a UFC world champion hard to come by at any level of professional boxing.
Like all great counter-punchers, McGregor’s technique relies on feints, but in the eight-sided MMA cage, he can feint not only punches, but takedowns and kicks, two weapons he won’t have in his arsenal come fight night.
Boxing purists have called Saturday’s fight a ‘circus’ and a ‘freak show’, and while those derogatory descriptions neglect the undeniable appeal, they do understand what, for many, is a simple fact: Conor McGregor is virtually certain to lose. That is not to diminish the Dublin-born star’s achievement in even getting to this stage – through sheer chutzpah, he has effectively talked his way into one of the biggest fights in history, and with it, a payday he has immodestly described as “well over $100m”.
He remains one of the best pound-for-pound fighters in MMA, and is the biggest draw bar none for the UFC, who will have to break the bank to tempt him back into the Octagon no matter the outcome of the fight against Mayweather.
It is also testament to his gift of the gab that he is even talked of in the same breath as Mayweather, a controversial figure but undeniably one of the greatest talents to ever grace the sport of boxing.
Mixed martial artists utilise the skills of a number of combat disciplines, including jiu-jitsu, submission grappling, wrestling, kickboxing, and even judo and karate.
To give an idea of how the fight on Saturday may transpire, consider what chance an expert in the field might give McGregor in a straight wrestling match with an Olympic gold medallist, or against a black belt Judoka.
Aside from partisans and contrarians, the overwhelming consensus would be that McGregor would be far out his depth in one of those disciplines, and would be handily defeated.
And that is how most with a passing knowledge of boxing consider the most likely outcome between McGregor and any high-level boxer, not least against Mayweather, a man closing in on 50 wins, and on whom opponents barely landed a glove during a 21-year career that saw him rise to legendary status.
That’s not to say tomorrow might not be entertaining – a circus atmosphere doesn’t always guarantee a farcical fight, and perhaps we will see something unexpected from the two men who have talked a freak-show fight into something approaching legitimacy. But the outcome should be in little doubt. Despite his advanced age, precious few boxers could even present a challenge to Floyd Mayweather, and Conor McGregor, making his pro debut, is not one of them.