Floyd Mayweather and Conor McGregor are going to make a whole lot of money once the opening bell rings for their fight Aug. 26.

What happens next seems like it should be clear.

McGregor, the only fighter in UFC history to hold titles simultaneously in two weight classes, will be competing in his first professional boxing match against arguably the greatest boxer of all time. Oscar De La Hoya, albeit as a rival promoter, suggested McGregor shouldn't even be licensed to box.

Yet, what happened shortly after the fight was announced suggests otherwise. In the days after the fight was confirmed, tons of small bets came in on McGregor, with the public seemingly confident he could give Mayweather more of a go than the oddsmakers initially suggested. While most of the early money is on Mayweather, the flurry of "square" action suggests there's at least some segment of the population that thinks McGregor has a shot.

Anything can happen in a fight, but it's harder to reconcile the betting action backing McGregor with a feasible path to victory beyond landing the luckiest of lucky punches. There are huge obstacles facing any UFC fighter crossing over to boxing, as there would be for a boxer crossing over to mixed martial arts. Crucially, Mayweather is just about the worst possible opponent for a fighter like McGregor, in terms of in-ring temperament and style. The arguments McGregor supporters have thrown out in his defense are flimsy and often incomplete.

The evidence against McGregor being able to compete in the fight is strong:

Conor McGregor is a big underdog to Floyd Mayweather for their fight on Aug. 26. Jeff Bottari/Zuffa LLC/Zuffa LLC via Getty Images

McGregor's not a professional boxer (and that matters a lot).

This is a very strong place to start any discussion surrounding this fight. It's hard to imagine anyone taking the discussion of an all-time great professional versus an amateur seriously in any other sport.

Of course, the idea is that MMA is a reasonable analogue for boxing, and in the UFC, McGregor is a world-class striker. He has racked up seven of his nine victories in the UFC by knockout or TKO, with the exceptions being a fight at a higher weight class (Nate Diaz) and one during which McGregor tore his ACL (Max Holloway). All of those finishes have been via punches, and McGregor is universally regarded as a creative, technically compelling striker.

It's also probably unfair to compare boxing in 4-ounce gloves to the 10-ounce gloves that will be used in the McGregor-Mayweather fight. McGregor has the hand speed to get ahead of his opponents in the Octagon, but he's also fighting in a sport where his opponents have to worry that he'll throw kicks or, at least theoretically, attempt a takedown.

A boxer who stepped into a cage and adopted a boxing stance would be picked apart by leg kicks, as was the case in the famous mixed match between Muhammad Ali and pro wrestler Antonio Inoki in June 1976. In a boxing ring, with kicks being illegal, Mayweather won't have to worry about checking them or worrying about takedowns, which fundamentally changes his footwork versus that of a typical McGregor opponent. He'll be defending himself differently with 10-ounce gloves.

McGregor backers have pointed out that he was once an excellent amateur boxer in Ireland. As an amateur, it's true that McGregor showed promise. He reportedly won a Dublin Novice Championship as part of 40 amateur fights between the ages of 11 and 17. There are no details on his record, but coaches and trainers who witnessed him spar suggest he could have been a successful boxer had he stuck with the craft.

It's hard to reconcile McGregor's amateur success with some idea that he's going to be able to compete at the highest level with a superstar boxer, though. McGregor never even entered the National Junior Championships in Ireland, let alone the Senior Championships. There's no guarantee he would have won any of those events. He never came close to qualifying for the Olympics as a boxer.

Thousands of boxers who attempt to make it through that crucible fail to win amateur titles, let alone turn professional. Just about everyone Mayweather has fought at the peak of his career had a far more storied amateur career. Andre Berto and Miguel Cotto were Olympians. Manny Pacquiao was on the Filipino Amateur National Team. Shane Mosley won medals in the World Junior Championships and Goodwill Games. Mayweather himself won a bronze medal in the 1996 Atlanta Olympic Games, where he suffered a controversial loss to Serafim Todorov in a fight even Todorov believes might have been due to suspect judging. That fight was the last time Mayweather lost in a boxing ring.

Even if McGregor were the best boxer in the world at age 17 -- and there's no evidence that he was anything close -- it would have been close to impossible for him to have kept up at a high level, even while training MMA. Nobody doubts McGregor's work ethic, but he has spent untold hours training everything from taekwondo to jiu-jitsu. Every hour he has spent training those disciplines is an hour Mayweather has spent on boxing.

To that end, boxer Chris Van Heerden released a video that shows him landing punches on McGregor while the two sparred in 2016. It's not entirely fair to use sparring sessions as proof of performance, and Van Heerden was the 11th-ranked welterweight in the world per the WBA rankings as recently as April and has a 25-2-1 record as a pro boxer. But he's also not in Mayweather's league. At the very least, McGregor has a lot of catching up to do.

Mayweather is the worst possible opponent.

Although it remains to be seen how it will translate to boxing, McGregor's knockout power in 4-ounce gloves is unquestioned. Ask Jose Aldo. If McGregor catches anyone flush, he's going to do serious damage. If McGregor were boxing someone who was inclined to get into exchanges and scrap, he would have a serious chance of causing some trouble.

The exact sort of opponent McGregor wouldn't want to face is a brilliant defensive boxer who has built his entire career upon keeping himself out of danger against more dangerous opponents.

Guess what Mayweather does best?

McGregor's biggest strength is pure knockout power, and he's facing a fighter who hasn't been knocked down by a punch in his professional career. Mayweather took a knee in a 2001 fight against Carlos Hernandez with a hand injury, but while it was a rough night for Mayweather, he still cruised to a unanimous decision.

Mayweather gets hit and placed into moderate trouble about once per presidential term. Plenty of fighters lose their chins as they get older and suffer from the wear and tear of fighting for decades, but how often is Mayweather, who is now 40, really taking shots to the face?

Perhaps McGregor can talk his way into Mayweather's head and convince him to brawl. Given that Mayweather has been able to do that to his opponents, though, and nobody has been able to get him off a sound defensive gameplan for any length of time, it will take a Herculean effort from McGregor's mouth before he steps into the ring.

Conor McGregor is the only man in UFC history to simultaneously hold two belts. Jason Silva/Zuma Press/Icon Sportswire

McGregor's not a similarly pedigreed MMA competitor.

I suspect the hype for this fight will pitch the tussle as the best UFC fighter of his generation versus the best boxer of his. Mayweather, a former five-division world champion, can make the latter claim, although the idea that he's the best fighter of all time might be a stretch. It's difficult to do the same for McGregor, even as UFC president (and fight promoter) Dana White suggests as much.

McGregor has been the main event on six UFC cards, going 5-1 in those fights. His opponents in those bouts have been a mixed bag. Diaz and Dennis Siver are midcard fighters with a combined UFC record of 26-17. Chad Mendes took his bout against McGregor on two weeks' notice and dominated the first eight minutes of the fight before gassing out. Aldo had been a superstar, but looked like a physically different fighter on the way to the ring versus McGregor and hasn't looked like his old self since. Eddie Alvarez looks to be McGregor's only elite opponent to go down at the top of his game.

It would be foolish to suggest McGregor's a fraud, because he's a very good fighter. It's also fair to say he hasn't had the staying power of a Demetrious Johnson, who has defended his flyweight title a record 10 times and hasn't lost since 2011. He's nowhere near as dominant as Ronda Rousey was at her zenith. McGregor hasn't shown the otherworldly instincts or ability to outclass his opponents that Anderson Silva showed at his best, when Silva rolled off 16 consecutive victories in the UFC and made fighters at both 185 and 205 pounds look foolish.

McGregor is one of the best mixed martial artists in the world, but it would be a stretch to call him the best. Mayweather's 49-0 record speaks for itself. You can make a case that he might have had trouble with fighters like Paul Williams or Antonio Margarito in their respective primes, but arguments he systematically ducked fighters are flawed at best. Maybe he would have struggled with Pacquiao or Miguel Cotto if he had faced them years earlier. Mayweather also has fought a far more star-studded list of opponents in his discipline than McGregor has in his.

And there is no easy flipside

The arguments for McGregor aren't unreasonable, but they don't scale to be anywhere near as significant as the arguments against him. Some of them don't really hold up to further scrutiny.

Even boxing great Manny Pacquiao couldn't figure out Floyd Mayweather in their 2015 bout. Mark J. Rebilas/USA TODAY Sports

Floyd struggles against southpaws.

In selling the fight, White pointed out how Mayweather has historically struggled against lefties such as McGregor. De La Hoya went a step further. "The left hand is the kryptonite for Mayweather," de la Hoya said in 2015. "He just does not know how to block a jab. It's just not part of his arsenal."

De La Hoya was making those comments in advance of Mayweather's fight with Pacquiao. You already know that Mayweather beat Pacquiao with relative ease, but what's even more notable is how he did it. During that megafight, Pacquiao landed just 9 percent of his jabs. Nine percent! It seems like Mayweather found a way to deal with jabs.

It's fair to note that Pacquiao, a lefty, injured a shoulder in advance of that bout and fought anyway. It's also worth pointing out that the arguments suggesting Mayweather struggled with lefties before Pacquiao weren't very strong.

Mayweather had issues with lefties very early in his career, but it's also fair to wonder if that was really the same fighter as the Mayweather who peaked after the turn of the century. Zab Judah rocked Mayweather and probably should have earned a knockdown, but Mayweather won that fight comfortably by unanimous decision.

At the same time, Mayweather was hit even harder by Shane Mosley, who fights in an orthodox stance, and used what might have been magic to stay on his feet. Mayweather's most difficult fight was probably against Jose Luis Castillo, another fighter with a traditional stance. It's logical that Mayweather would prefer to fight orthodox opponents given his style, and by all accounts, it's true that he wasn't in a rush to fight left-handed boxers earlier in his career. He's also 9-0 against them with four knockouts, and in his last fight against the best lefty of this generation, Mayweather outclassed Pacquiao. I'm sure he would prefer it if McGregor worked out of an orthodox stance, but it's not some fatal, unaddressed flaw.

McGregor's in his prime, whereas Mayweather will be coming out of retirement at age 40.

The easiest argument to grasp in terms of contrasting these two fighters is where they are in their respective careers. McGregor's very much in his prime as a 28-year-old, and he has kept his skills honed with three fights in both 2015 and 2016, although he hasn't fought since November. Mayweather turned 40 in February and hasn't fought since September 2015, when he comfortably dispatched Berto in Las Vegas.

While every fighter is going to be worse at 40 than he would have been years earlier, there's little evidence Mayweather has declined much as he has gotten older. He looked better in the rematch against Marcos Maidana than he did in their first fight, five months before. After outclassing Pacquiao, he did the same to Berto, who was more than seven years younger than Mayweather. Canelo Alvarez, who was 6 when Mayweather made his professional debut, was 13 years younger than Mayweather when they fought in 2013 and wasn't able to turn his youthful vigor into a competitive fight.

It's more plausible that the layoff would have an impact on Mayweather's skills, given that he hasn't been training for a fight for two years. There are examples of great fighters who weren't the same after a long stretch out of the game; think about Sugar Ray Leonard, who retired after his third fight with Roberto Duran in 1989 at age 43 with a 36-1-1 record. He returned nearly two years later but lost to Terry Norris.

On the other hand, there's Sugar Ray Leonard, who missed two years with a detached retina before returning at 27 to beat Kevin Howard, then sat out three more years before returning again to beat Marvin Hagler at age 30.

There aren't many fighters with Mayweather's record who have retired and made their way back into the ring years later with success, but there are precious few fighters with Mayweather's track record who have retired before taking their first loss, too.

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McGregor will have a size and reach advantage.

This is the strongest argument in McGregor's favor. One of the few concessions he might have picked up in negotiations would be the weight at which the fight will take place. McGregor will step onto the scale for weigh-ins at 156 pounds, which should give him the weight advantage, given that Mayweather finished his career fighting at 146. McGregor's punches failed to find their mark on a larger man when he fought Diaz, but those power strikes will mean even more if they land Aug. 26.

Perhaps more important, McGregor comes into the fight with a 2-inch reach advantage, with a 74-inch wingspan compared with Mayweather's 72-inch wingspan. Mayweather has typically had the reach advantage in his fights; a look through the reach listings available at boxrec.com suggest that Mayweather has had an advantage in each of his past 10 fights, by an average of nearly 4 inches. The last time Mayweather might have struggled with reach concerns was against De La Hoya, who is listed alternately with a 72- and 73-inch reach, depending upon the source. That fight did end as a split decision, which qualifies as a tough matchup, given Mayweather's standards. On the other hand, Mayweather had longer arms than De La Hoya, which might not be the case versus McGregor.

One other element of this argument is that McGregor's typical reach advantage will be impacted by the presence of the padding in 10-ounce boxing gloves as opposed to the 4-ounce, open-fingered gloves used in MMA. The added padding should theoretically help both fighters, given that it would make it easier for McGregor to impact Mayweather from afar, but it also seems realistic that the guy who has been fighting with boxing gloves on for two decades now would make better use of that inch or two of range than the relative novice would.

McGregor's taking a laudable risk by talking his way into this fight, which speaks to his self-confidence and the globs of money he's likely to earn after a mountain of pre-fight hype. He's an underdog only by virtue of circumstance. If the rules were reversed and Mayweather were taking on McGregor inside the Octagon, it would be easy to flip this same story and break down how Mayweather would need to change his footwork and style overnight and still probably end up being taken down over and over again.

The 'boxing vs. MMA' fallacy

As tempting as it will be to declare some sort of winner between boxing and MMA at the end of this fight, it's a foolish, useless exercise in 2017. We should know better by now that the arena is far more important than the individual fighters. Freak-show forays between the two disciplines, such as James Toney's ill-fated attempt to fight former UFC champion Randy Couture in the Octagon, have never been relevant; real crossover attempts from fighters such as Marcus Davis, Chris Lytle and Holly Holm have been met with mixed success, with Holm's stunning upset of Ronda Rousey being the highlight.

The closest comparison for these two stars and the mixing of these two athletes would be if Usain Bolt were to step away from his sprinting career and challenged Eliud Kipchoge to a marathon. If Bolt and Kipchoge met somewhere in the middle in terms of distance, the result might be in question. Likewise, if McGregor and Mayweather were fighting in a more mixed atmosphere -- if they were kickboxing, or McGregor were allowed takedowns without the ability to follow up on the ground, or if they alternated boxing and MMA rules in each given round -- it would be a fascinating fight to analyze.

Instead, there's a reason the bookmakers at William Hill suggested McGregor's true odds of winning are 100-1. This is about as lopsided as any individual matchup you'll ever see, although the next three months will be spent trying to convince the viewing public otherwise. McGregor has a chance -- it would be even more naive to count him out altogether in the era of Leicester City winning the Premier League at 5,000-1 -- but a puncher's chance might not be very much if he can't get near the best boxer of this era.