The fact that Conor McGregor vs. Floyd Mayweather are even fighting, let alone that this will likely end up being either the first or second biggest grossing event in the history of combat sports, is a testament to the change in the economics and in the media.

Fights similar to this have been talked about since the beginning of time, but they were almost never made, because in the past it never made any financial sense to happen.

And the one fight people talk about when it comes to a historical comparison, the June 25, 1976 fight between Muhammad Ali and Japanese pro wrestler Antonio Inoki, underscores just how different things are today.

The circumstances are a perfect storm of things all coming into play. MMA has never had a major star who could be in a promotion of this level, nor did any other combat sport other than just a handful in boxing. And the economics were so different. Even adjusted for inflation, pay-per-view technology changed the times, so the big drawing boxers of the past, from Jack Dempsey to Ali, were never put in a position where they had an opponent quite like McGregor to pull this off.

A key reason this fight is happening is the success of the 2015 Mayweather vs. Manny Pacquiao fight, which grossed more than $600 million. It set a standard for one-day revenue for a fight that changed expectations about what was possible.

So, for the first time ever, the biggest drawing card in boxing faces the biggest drawing card in MMA. The key is in fight promotion, when something works, it is copied until it stops working. If the event is viewed as a success from a financial perspective (which it will be) and it doesn’t leave a bad taste in people’s mouths, this type of cross-sport fight will almost surely happen again.

And what makes it so unique is that in the one instance historically where something close to this could have happened, the discussions were always of a mixed rules fight. A straight boxing match essentially means that McGregor and the sport of MMA are, at least on paper, doing a one-night sacrifice of themselves to the public for a giant payoff. Of course, everything both sides have done in the promotion is designed to make the public feel that isn’t the case.

This is all about money. McGregor can make $10 million or $15 million for a fight in UFC when he's matched with the right opponent. But it is inconceivable he can make $100 million. A key aspect to this story is that the biggest MMA drawing card in the sport can earn exponentially more money doing a boxing match than he can a fight in his own sport. In theory, that’s not a good thing for the sport of MMA, but when it comes to business, the short-term gain is probably substantially more than any long-term damage.

Just as important when it comes to the future is that Mayweather, if the fight does the kind of numbers people are throwing around, will earn far more money fighting a non-boxer in a boxing match, than a top boxer, and with far less risk as far as losing goes.

The difference from 10 years ago, when Mayweather fought Oscar De La Hoya in the first fight to ever top 2 million buys on pay-per-view, are astounding. De La Hoya was a gigantic name, and what people forget about that fight is that going in most expected the fight to do about 1.5 million buys, because that was believed to be the ceiling for a non-heavyweight fight.

Blowing that number away and doing 2.45 million buys was due to the success of the weekly 24/7 style countdown shows that have now become a staple in big fights. That fight established two things. The first is that the mentality that it had to be heavyweights to draw the real record numbers was an antiquated viewpoint. De La Hoya had established himself as combat sports’ biggest star and others, like Ray Leonard before him, were on top. But the mentality was that neither would ever be able to do “Tyson numbers.”

Even in the UFC, it was the bigger guys who were the top draws. The featherweight division that McGregor came up in didn’t even exist in UFC until years later.

Promoters and fighters will likely acknowledge that there is only one Mayweather and one McGregor, but if there is an MMA champion who is a striker, and UFC heavyweight champion Stipe Miocic has already thrown out the challenge to Anthony Joshua, the idea that they could earn far more money for losing a freak show fight than they could for a championship defense is going to have a similar lure.

They won't make nearly the money this fight will, but the key is will it, using the boxing formula of paying main eventers, enable the UFC fighter the opportunity to make more than for a UFC title defense? UFC would want to block a steady stream of its champions losing to boxers. But after this event, unless the fight itself is a flop, the mentality will be to copy what made it work.

Kickboxing was never big enough in the U.S., the prime market for giant money events, to have a fighter who could draw like McGregor against a boxer. Amateur wrestling stars never had the notoriety. Some pro wrestling stars had the notoriety, although at no point in history could any fight generate the kind of interest this one will, because of the change in media and the promotional skills of McGregor.

Over the years there were many wrestler vs. boxer matches, some under mixed rules, and a few under boxing rules. None ever garnered a smidgen of interest this already has.

In the early 1920s, there were negotiations to pit Ed "Strangler" Lewis, one of the two biggest pro wrestling stars of that era, against Jack Dempsey, “The Manassa Mauler,” the heavyweight boxing champion. At that time, there was no bigger sports star than the heavyweight boxing champion, and while wrestling was already predetermined, it received extensive newspaper coverage and The Strangler vs. The Mauler looked like a huge promotion.

In the end, the fight never happened since Lewis wouldn't dare do a boxing match with Dempsey, and Dempsey, even though he said otherwise, knew well enough that in a mixed rules match, he'd stand little chance. The interest at the time was for a mixed rules match, and economically, it was dangerous to Dempsey and boxing. There wasn't enough of a money difference between what Dempsey could make boxing to have it make any sense for him.

Over the years, there were numerous boxer vs. wrestler matches, although most were in pro wrestling, and the outcomes were predetermined, as numerous boxing champions from Joe Louis to "Jersey" Joe Walcott to Leon Spinks took to pro wrestling after their boxing careers were over. Joe Frazier even did a match in Puerto Rico. In recent years, long after anyone took it seriously and it was clearly all in fun, people like Mike Tyson, Evander Holyfield and Ricky Hatton messed around on WWE shows.

In the few legitimate fights, the results were almost predetermined, in the sense the rules made the outcome obvious. Frank Gotch was in many ways the first celebrity pro wrestler, who, as world champion, was viewed as legitimate in his day. He used a pseudonym, Frank Kennedy, and lost a boxing match to Frank Slavin in 1901 in The Yukon Territory. There was also the brutal 1940 bout where an aging Dempsey destroyed Cowboy Luttrell under boxing rules.

In a 1935 bout, wrestling star Ray Steele battled boxer Kingfish Levinsky in St. Louis, under mixed rules, and it only lasted 35 seconds with Steele winning. While it took longer, in a 1963 mixed match, wrestler/judoka Gene LeBell defeated boxer Milo Savage. Pro wrestler Kiyoshi Tamura, who later had an MMA career that included wins over Kazushi Sakuraba, Pat Miletich, Renzo Gracie and Maurice Smith and a draw with Frank Shamrock when Shamrock was UFC champion, finished past-his-prime boxing champion Matthew Saad Muhammad in 34 seconds in 1992.

Once MMA got established, a past-his-prime Ray Mercer lost to Kimbo Slice but later knocked out former UFC heavyweight champion Tim Sylvia in nine seconds. That’s really the only high-profile case where a boxing champion defeated an MMA champion under MMA rules.

Pride heavyweight Kazuyuki Fujita choked out former cruiserweight champion boxer Imamu Mayfield in 2003 with rules that limited ground work to 20 seconds, when he was able to lock in a choke while standing. And the current era UFC once pushed a boxer vs. MMA fighter theme when James Toney submitted in the first round to Randy Couture. On the first UFC show in 1993, Royce Gracie quickly took down boxer Art Jimmerson, who then immediately wanted out.

From an intrigue and fair standpoint, a mixed rules match, perhaps kickboxing rules, may have had even more intrigue for Saturday in Las Vegas. But most concede that unless Mayweather connected early and McGregor couldn’t recover, that if kicking was added to the rules, it would be Mayweather who would have almost no chance.

None of these historic instances truly parallel Mayweather vs. McGregor. In the past, such a fight could never happen because the top star in one venue would never risk both his own reputation and that of their sport in a situation where they have little chance to win. And to be fair, none of the non-boxers involved were anywhere near the level of striker that McGregor is, nor the level of talker, and in this case, the latter is more important in this happening than the former.

The closest example from a name value and marketing standpoint of a fight that actually did happen was Ali vs. Inoki. When it happened, the fight was widely considered a joke and got far less media publicity than one would think, given Ali was a far bigger cultural star in 1976 than either Mayweather or McGregor are today.

Why that fight did happen is that Ali was offered more money for what was supposed to be a pro-wrestling match, where he would lose to Inoki, than he had ever earned for a boxing match. But in the week before the fight, Ali suddenly decided that he didn't want to lose. At that time, nobody knew whether the fight would or wouldn’t be real. It was promoted as being real. It was held in Japan, where there were no regulations, away from the regulatory bodies in the U.S. The media didn’t know, but at the time, most were skeptical of the legitimacy of it, and unlike with McGregor, almost nobody in the media or the U.S. knew who Inoki was.

The Japanese backers of Inoki were looking at Ali losing to Inoki, with the idea such a win would make Inoki, already a big star in their culture, into a national hero like no athlete in their country could have been.

They were not paying Ali $6 million to beat their guy in a sports contest; it was all about paying to make a Japanese idol.

However, when Ali said he wouldn’t lose, they were too far into the promotion to back out, particularly when, if the fight didn’t happen, it would surely get out that the fight was fixed for Ali to lose and he refused. That would have destroyed Inoki in Japan at that time.

Instead of calling the fight off, which it was very much in danger of in the days before it happened, they agreed to do a real fight. It’s funny, because today, in Japan, this fight is generally considered the birth of MMA, but it was never intended to be anything but a pro-wrestling match, like Inoki had during that era with other boxers and stars from karate and judo.

Ali had all the bargaining power at the last minute. So he was able to get rules greatly in his favor. Even with Inoki banned from using submissions, kicks above the waists, Greco-Roman throws and other wrestling techniques, the lopsided rules were still not pure boxing. The fight ended up as a boring 15-round draw which saw mostly Inoki lay on his back and blister Ali with leg kicks.

At the time, the public viewed Inoki as a coward who wouldn't stand up and fight. Today, with judges who understood low kicks, Inoki would have won at least 12 of the 15 rounds. Keep in mind this was one of the greatest heavyweight boxers who ever lived against a pro wrestler. Inoki trained in submissions and was Japan's biggest star, but behind the scenes was never considered a legitimate top-tier shooter like a Billy Robinson was in the era.

Ali was also nearly involved in another freak show fight in 1971 with Wilt Chamberlain, who was the biggest name in the NBA at the time. The idea behind it was that the public would be intrigued by the size difference. Chamberlain was 7-foot-1 and 290 pounds. But after a press conference that got national attention, and numerous publicity photos, the fight fell apart. Because Chamberlain in the culture was so well known, that fight may have done well business-wise, but we’ll never know.

Ali was a far bigger star than either Mayweather or McGregor is today, but the economics were completely different.

Still, when Ali vs. Inoki was put together, the thought process was the fight would do big business on closed-circuit at arenas around the U.S. and Canada, because you would get both the fan bases of pro wrestling and of boxing. That's similar to the mentality of McGregor vs. Mayweather bringing together the fan bases of MMA and boxing. In reality, the success of this show, like with Mayweather vs. Pacquiao, is more about people who aren’t fans of either sport, capturing the type of person who isn’t a sports fan, but still watches the Super Bowl every year.

Ali vs. Inoki was a financial bomb in North America. Outside of the Northeast, where the real draw was a pro-wrestling match with Bruno Sammartino against Stan Hansen at Shea Stadium, and in Japan, where it did a record gate and is still one of the highest rated television shows in the history of TV-Asahi, the fight bombed.

As big as Ali was, the public didn't buy the concept. Inoki wasn't well-known in the U.S. Ali ended up getting less than $2 million when all was said and done.

When Mayweather fought Pacquiao, after years of teases, the predictions were it would be 3 million buys on pay-per-view, but general public interest at the last minute blew that figure out of the water. In doing 4.6 million buys, it did a figure that few even felt was possible.

It also led to the expectations of this fight, where people are talking 5 million buys and revenue figures to where the fight could generate more money in one night than the entire UFC did in its record-setting 2016.

What is different today is the mentality of the fans and the changes in the media.

As big a star as Ali was, the event got some coverage, but not a lot. Most sportswriters, sportscasters and sports editors were skeptical the fight would be real, and with good reason. They didn't want to give it credibility in the event that it wasn't. And even if it was, the important thing in the sports world wasn't Ali, but Ali's heavyweight championship, which wasn't at stake.

Championships in those days were bigger than the stars. Today, that's no longer the case. The coverage it did receive was more like it was a novelty, and almost all tongue-in-cheek. The public was told it wasn't important, and for the most part, they believed it and didn't buy it.

Today, the media has changed. It's all about personalities, not competition or championships. If the personalities can draw ratings or get hits, they'll get constant coverage. Every tweet by McGregor and Mayweather becomes a news story. The biggest differences are not just how much more money can be made via pay-per-view than the old closed-circuit, and how much more money people are willing to pay for sports events today, but that in 1976 the media led the public to what was important. Today, the public leads the media.

No matter what people in sports think of the idea of a mismatch or sports value of a fight that many experts would say is all but predetermined based on the rules in place, there will be round-the-clock coverage in the days leading into the fight. McGregor, Mayweather, Dana White and all parties involved will be telling you this is the biggest fight in history. It’s a must-see event. And like has been the case the past few weeks, they’ll be trying to sell you on the idea that McGregor has a chance to win.

The idea that no championship is at stake in this fight is completely immaterial.

In the past, Zuffa did everything in its power to keep its top stars, notably Nick Diaz when he wanted to box Jeff Lacy, from going into boxing, with the idea losing in another sport and looking bad would damage their marketability.

But in this instance, unlike any other time in history, the money is so big that the UFC and McGregor are willing to sacrifice their aura to the general public because the economic windfall of the night is too great to pass up.