Ever since the first mentions were made of a super-fight between Floyd Mayweather and Conor McGregor, people divided into two camps.

There were those who considered the bout – now officially in the books – a circus show. It was essentially being treated by this group as non-canon, certainly for Mayweather’s career if not those of both fighters, with an expectation that it might one day be looked back upon as something akin to footballers like Pelé and Franz Beckenbauer winding down their professional careers in the first incarnation of the North American Soccer League.

On the second side were those who anticipated a genuine contest. The majority of this group were firmly in McGregor’s corner, believing the Irishman could bring something to the table that his opponent has never had to contend with before. To those fans, this bout was more than just a payday for both men.

Separate from these groups, though – and away from what Mayweather’s win means for his and Conor’s career – we have those debating instead why boxing found itself in a position where a fight like this became possible. How did a fight between the self-confessed ‘TBE’ and an 0-0 debutant become the most financially significant fight of all-time?

While broad PPV numbers for the sport are hardly insubstantial, they’ve been on a decline and the one-on-one rivalries at the top of the game aren’t what they used to be. Mayweather-McGregor was a personality-driven fight, fuelled by the hate we wanted to believe these men had for eachother.

It begs the question, does boxing need grudge rivalries to flourish? Is that more important than genuine competition?

"It was a grudge match that turned Anthony Joshua into a superstar."

There’s even an argument that the rivalry between Lionel Messi and Cristiano Ronaldo has long overtaken anything boxing has to offer when it comes to one-on-one competition – a confusing dichotomy considering the team sport element having the power to dilute anything football should have to offer in this realm.

However, while Messi vs Ronaldo may feel watered down for some by the presence of multiple Clásico meetings every season, it was the opposite for the Mayweather vs Pacquiao rivalry, a head-to-head whose ultimate disappointment might be regarded by some to necessitate Mayweather-McGregor, almost as a consolation prize for audiences if nothing more.

It’s unarguable that narrative and momentum play a much larger role in boxing and MMA than any other sport.

This is where other more recent rivalries become so intriguing: Anthony Joshua’s 2015 defeat of Dillian Whyte was preceded by a back-and-forth that carried a genuine stench of animosity, and it showed in the ring with the pair both giving everything. It’s no coincidence that AJ’s first fight after Whyte was for the world heavyweight title. A grudge match turned him into a superstar. Talk of a rematch between the two, while not an obvious choice in terms of the pair’s respective standings, would make financial sense.

It is the same logic that brought Nate Diaz into the fold as an opponent for McGregor after Rafael dos Anjos’ injury in 2016, despite Nate’s less-than-stellar record in the years prior: two rivals going all-out before, during and after a bout can provide enough value to supersede more ‘natural’ match-ups when it comes to watchability. The presence of two excellent technicians, while appealing in the moment, has little likelihood of capturing public imagination, making even the most intriguing tactical battle less visible. The involvement of an American to a one-on-one rivalry is not insignificant either – as a worldwide enterprise, sportswriting and broadcasting comes in English with an American accent. Speaking fluent English is sometimes enough, meaning a rivalry between Wilder and Anthony Joshua could yet take centre stage in the way that a Canelo Álvarez-Gennady Golovkin axis has struggled to gain traction beyond preaching to the converted.

The same goes for the UFC, where one of its most successful champions – Brazil’s José Aldo – has gained more mainstream notoriety from a defeat to English-speaking Conor McGregor than he did in his seven title defences, and where discussion of undefeated Russian lightweight Khabib Nurmagomedov often comes back to how sellable he would be if only he spoke fluent English.

It feels, for now at least, that there was no pairing capable of filling the void in either sport, meaning the bout between Mayweather and McGregor took centre stage for both.

"Mayweather's career was defined by dominance. Until McGregor, no-one came close enough to be a rival."

Mayweather’s career is defined by dominance, in part by being ‘the best’ but just as importantly by conquering the granular, by beating everyone put in front of him individually. There is an argument that this element to his psyche explains his lack of a great rival – no one ever threatened him or his status enough to make things interesting. McGregor came close, not in the ring as you might expect, but by legitimately ousting Floyd as the new face of the fight game.

Unlike Muhammad Ali or Mike Tyson before him, Floyd had no defeat to avenge. The longer Mayweather went without someone crossing that boundary, the more difficult it became for him to find his equal – maybe we shouldn’t be surprised that, in McGregor, he has found an opponent who was always in danger of facing some of the same problems in his primary sport.

This is not an issue that has always existed in boxing, with Ali vs Frazier and Tyson vs Holyfield each, in turn, positioning boxing towards the top of its own rivalry with other sports. Perhaps due to the purity of its one-on-one combat, boxing has always prided itself in an ability to bring its biggest rivalries to the fore, even when presenting them to an audience who know full well that logic dictates the Venn diagram between the most talented and those with the biggest personal beefs will never have a massive overlap.

The aforementioned Ali-Frazier and Tyson-Holyfield battles also existed without the shadow of a Mayweather figure, someone not only so dominant but so aware of their own dominance that he was able to steer the conversation away from the heavyweight division. There is a correlation-versus-causation factor here, of course – did Mayweather’s dominance weaken the heavyweight conversation as the 21st century endured, or did the decline in heavyweight narratives open a gap for the American to stride through?

Some sports seem to need rivalries more than others, as shown in the relative decline of heavyweight boxing in the Mayweather-Pacquiao era, while others, like football, can survive without, only to then appreciate their value when something like the once-in-a-lifetime Messi vs Ronaldo problem arrives.

24 months ago, it was inconceivable to think Mayweather-McGregor would be the most lucrative rivalry in the history of boxing. Sometimes a great rivalry can establish itself by filling a gap that we didn’t even know was there.

@TomVictor