The Floyd Mayweather-Conor McGregor purse is expected to historic. Some estimates have the total purse over $400 million. USA TODAY Sports

One of the most astonishing things about Conor McGregor’s Aug. 26 fight with Floyd Mayweather is that the Irishman is not a bigger underdog with Las Vegas oddsmakers.

Despite McGregor, the Ultimate Fighting Championship star, never having boxed competitively, Mayweather is priced at minus-500 (a $500 wager wins $100), shorter than the minus-700 when he fought future Hall of Famer Miguel Cotto in 2012.

Such odds typically indicate money wagered rather than a reflection of the chance of one side winning. Yet even among boxing sages McGregor’s hopes are being talked up more than expected.

But how could he possibly hope to do it? How could Mayweather’s defensive gifts and flawless technique be unpicked by a rookie? There are some ideas percolating, some far-fetched, others offering some potential.

1. The puncher’s chance

First is the concept of the puncher’s chance, which has been used to drum up interest in countless lopsided boxing matches. In theory, it makes sense. However dominant a superior technical boxer has been, a single punch can always end a contest if it connects correctly.

“Anywhere on the dome,” McGregor taunted Mayweather during their media tour last month, meaning that his punching power is so strong that if he lands on any part of Mayweather’s head it has the potential to knock him out.

Despite it being a boxing term, the “puncher’s chance” is often discussed in mixed martial arts. Former McGregor opponents Nate Diaz and Eddy Alvarez say that an early knockout is McGregor’s only hope and that swinging for a monstrous head shot is his best chance. Holly Holm, who was world boxing champion before heading to the UFC and defeating Ronda Rousey, agreed.

“It will be easier for Mayweather … the longer the fight goes,” Holm told MMAfighting.com. “If McGregor wins, it will be in the early rounds. Anything can happen.”

However, of the boxing believers, the thought of Mayweather getting beat early is unthinkable. Many have tried a swarming, headhunting approach before, and haven’t gotten anywhere near him.

2. Get in Mayweather’s head

Heavyweight legend George Foreman says there is another way McGregor can get his teeth into the fight, by frustrating and toying with Mayweather’s psyche.

“The last thing Mayweather wants is to be embarrassed,” Foreman told USA TODAY Sports. “Even if McGregor goes 12 rounds that would be a huge moral victory for McGregor, so Floyd is under some pressure.

“Mayweather doesn’t expect to get hit. If McGregor can get at him and land a couple of shots, then run around the ring and stay out of trouble, that is going to make Mayweather mad. That is when you might be able to exploit an opening. If you play it Mayweather’s way, which true boxers have to do because they are raised that way, there is no chance. McGregor has the freedom to be different.”

Abel Sanchez, trainer of Gennady Golovkin, also says McGregor has to find a way to irk Mayweather, though his preferred approach would be a little more high-octane. Sanchez insisted McGregor needs to focus not on a knockout, but on letting his fists fly.

“He has to try to hit him anywhere, face, body, chest, doesn’t matter,” Sanchez said. “He needs to let Mayweather feel he is there and force some kind of reaction.”

3. Be physical (and dirty)

One key universally agreed upon is that McGregor must try to get Mayweather out of his defensive comfort zone.

Rugged and tenacious, Argentina’s Marcos Maidana gave Mayweather one of his most difficult battles in 2014 by fighting on the inside, grabbing, clinching, keeping things tight, holding and wrestling. Maidana lost by majority decision, one judge scoring the bout a draw.

McGregor can get some benefit by doing the same, although any attempt to use MMA-style maneuvers is a non-starter, as stipulated in the fight contract, according to UFC president Dana White.

A bit of sly rough stuff, however, may serve McGregor well, particularly if he can keep it out of the referee’s view. It may have the dual effect of riling up Mayweather and also tiring the 40-year-old.

Foreman, welterweight icon Thomas Hearns, ex-heavyweight champ Evander Holyfield, a swath of UFC stars and White himself all say that being physical and uncompromising is the way to go for McGregor.

The problem may come in what leniency is allowed by the official, who is still yet to be named, and will have to be approved by Mayweather. If the ref clamps down quickly every time McGregor tries to work inside, it would work in Mayweather’s favor.

Critics of the former pound-for-pound boxing champion say that he enjoys too many unfair advantages, from the size and weight of the gloves, to the fact that he always fights in his hometown of Las Vegas, with referees familiar with him and his style.

As if any more of an edge was needed. Let’s not forget Mayweather is 49-0 as a pro boxer, with wins in 26 world title fights. The only other times he has come up against a boxing debutant, was in the first and fourth fights of his career.

McGregor has not chance at all. Or doe he?

GALLERY: BUILD-UP TO MAYWEATHER-MCGREGOR FIGHT