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The Floyd Mayweather versus Conor McGregor boxing match is absurd enough on its own.

A 49-0 multi-division boxing champion is set to face someone making his debut in the ring. That 0-0 fighter also happens to be the UFC's sole attraction and could well cash out on the promotion with this fight...and the organization seems to know that.

It's bananas, right? Still, fans have proved to be even bigger marks than the people profiting from the Mayweather-McGregor circus first thought.

How? By pushing the betting line from -2,250 vs. +950, to Mayweather being a -550 favorite and McGregor being a +375 underdog.

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Granted, a -550 versus +375 line is still pretty clear in regards to who is more likely to win the fight. With a $100 bet, that line yields a $375 profit from a McGregor win, but just a $20 return on a Mayweather win. The math speaks for itself.

That said, what makes those numbers so absurd is that they state McGregor is more more likely to beat Mayweather than many of Money's past opponents—opponents who were highly accomplished boxers.

Justin Hartling of OddsShark put together a handy table that shows the history of Mayweather's betting odds and the numbers strongly suggest McGregor is more likely to strip Mayweather's undefeated title than Marcos Maidana, Miguel Cotto and many others:

Betting Lines for Mayweather by Opponent Opponent Line Implied Odds of Win Conor McGregor -550 84.62% Andre Berto -3,000 96.77% Marcos Maidana (2) -600 85.71% Marcos Maidana (1) -900 90.00% Robert Guerrero -600 85.71% Miguel Cotto -700 87.50% OddsShark

Pundits have been fairly clear about where a McGregor win would stack up in the all-time list of upsets: decisively in first place.

ESPN's Max Kellerman flatly stated, "Conor will not land a single punch against Floyd," and few have strayed too far from his assessment when breaking down the fight.

The numbers here, however, suggest McGregor winning would be a surprise—but not really a shocker. Not only that, but it wouldn't come close to other great upsets such as Buster Douglas (a 42-1 underdog) defeating Mike Tyson or Holly Holm (who was +450 at the time of the fight) knocking out Ronda Rousey.

Of course, a shift in the betting lines wasn't unexpected. With the initial -2,250 line on Mayweather, a bet of $100 would have yielded just a $4 return. It's tough to lure people off the couch with that sort of return.

But for the lines to shift this far in such a short amount of time? It's truly absurd. Even more absurd than the fight itself.

Lines courtesy of OddsShark unless otherwise noted, implied odds obtained using OddsShark's Odds Calculator.