Even the experts are pouring over the tea leaves for this one, looking for signs to lead them to a decisive outcome. In a fight so beautifully poised a reasoned observer can be persuaded one way or another on any given day. In Britain, the weight of expert opinion sides narrowly with Saul ‘Canelo’ Alvarez. In the United States, Gennady Golovkin gets the nod.

What is not in doubt is the nature of the contest itself, one for the ages, a bout that takes us to the very core of what the noble art is all about; technique, courage, power, tradition, authenticity and respect, precisely the attributes lacking in the fairground spectacle that was Floyd Mayweather versus Conor McGregor under the same Las Vegas lights a fortnight ago.

Alvarez, the youngest of eight children, is the archetypal Mexican, brilliantly schooled in the fundamentals, minimalist, possessing the heart of a lion and lethal. Though eight years Golovkin’s junior he has been boxing as a professional for one year longer, conforming to the Mexican tradition of turning pro early, in his case at 15. His record shows 51 fights, though there could be at least 20 more lost in the small halls of dusty Mexican towns where no-one is keeping accounts.

Golovkin is a phenomenon the like of which we have never seen. Born the son of a miner in Kazakhstan under the old Soviet regime, he was introduced to boxing by his older brothers and blew all the records away compiling an amateur CV that reads 345 wins and only five losses.

As a professional of 37 fights he has never lost, never been down and gone the distance only four times, most recently in his previous engagement against Daniel Jacobs, who failed to make the weight and entered the ring almost a stone heavier than his opponent. Before that, we have to go back a decade to a time when Triple G was making his way in eight rounders in Denmark and Germany to find any who could withstand his freakish power.

The case for Alvarez is made on the basis of his crushing victory last time out over fellow Mexican Julio Cesar Chavez Jnr, who like Golovkin was the genetically bigger man. Chavez did not win a round in a one-way pounding. Golovkin, on the other, hand struggled to put away Jacobs after decking him with a flash knockdown in the fourth.

Jacobs was no fool. His failure to step on the scales, thus giving up the right to the titles at stake, suggests a trade off between belts and prestige. If coming in heavier was the only way to diffuse Golovkin’s relentless attacks then so be it. He wouldn’t be champion but he might just be the first boxer since his amateur days to get the better of GGG. It was a risk worth taking and for a spell in the second half of the fight looked to be paying off as he diffused Golovkin by switching from southpaw to orthodox, boxing behind a busy jab and going to the body.

That effort plus the extra timber ultimately undid him with Golovkin coming like a pitbull into the final round to get the decision. He wasn’t at his ruthless best but is one bad night sufficient to suggest he might be on the slide? That is the conclusion which some have drawn as they stare into those leaves.

In seeing a decline in Golovkin at the age of 35, Canelo’s advocates are choosing to ignore their man’s unconvincing displays against Austin Trout and Cuban Erislandy Lara either side of the one loss on his card to Mayweather Jnr four years ago. Southpaw Trout was the busier man and though the judges made the decision unanimous, other observers in the media had it much closer.

Cuban veteran Lara, like Trout, was on his toes and his movement gave Canelo trouble, but two of the three judges were persuaded by the power shots of the Mexican and awarded the fight to Canelo on a split verdict. As Mayweather demonstrated, movement and speed are the way to beat Alvarez, but there are few that combine those qualities like Pretty Boy Floyd. Golovkin comes armed with terrible power in either hand, a granite chin and belief, which amount to a red rag to a proud Mexican bull.

As Canelo’s manager, Chepo Reynoso, observed: “He (Golovkin’s trainer Abel Sanchez) says Triple G has a Mexican style. But I tell Abel that not only does Canelo have a Mexican style and a Mexican heart, but he IS Mexican!” With that remark, Reynoso is making this not only a contest between two men, but boxing cultures and heritage. Alvarez is at the upper end of Mexican reach in terms of the middleweight division. Not many campaign at so heavy a station successfully.

Alvarez began as a super lightweight, or light welterweight in old money, 140 pounds. Golovkin has campaigned his whole career at the 160-pound middleweight limit. While it is true that Alvarez struggles to boil down to the super welterweight (or light middleweight) 154-pound limit, it is arguably the division in which he is most effective.

Canelo vapourised Amir Khan last year at a catchweight of 155 pounds. Khan took a leap of faith jumping two weight divisions and was ahead on points when a big right hand detonated on his chin in the sixth. There is no jaw on earth that has the capacity to absorb punishment like Golovkin’s.

The pedigree of both, their willingness to take on any challenge elevates this WBA, IBF, WBC unification bout to the sport’s highest echelon alongside those 1980s duels when Ray Leonard, Roberto Duran, Thomas Hearns and Marvin Hagler went toe to toe. Those epic confrontations remain boxing’s reference point more than three decades on, inviting today’s heroes to take the story on if they can.

In his halting English Golovkin is never one for talking. Indeed when he stands to address an audience you might think he was attending a convention of Geography teachers, so unthreatening does he appear in his civvies. But oh what terror rains down when the gloves are on, a cold-eyed destroyer delighting in the violence unleashed. “I am ready,” he told a Vegas Press conference this week.

“I respect Canelo’s team. This is a big day not only for us, but for boxing and this era. This will be a huge historic fight at T-Mobile Arena. I feel comfortable. I see that Canelo is ready. He is ready for serious business, a serious fight. This fight will be the biggest gift to the people.”

Alvarez, too, kept the formalities to a minimum. “I just want to say that I’m prepared. I know it will be a tough fight. I just want you all to enjoy it like I’m going to enjoy it. The excitement is there. The adrenaline is there. I have nothing to say to him. They know what kind of fighter I am. I’m prepared. I’m ready. All I want to tell him is look, let’s give the fans a great fight.”

Okay, you want to know where my money rests? I’m backing the proven punch resistance of Golovkin, who will have felt hands as heavy as Canelo’s before. What is certain is that Canelo has never spent time in a ring with a middleweight who hits like Golovkin. I believe that is a factor that carries more weight than Golovkin’s age and the associated theory of decline.

Were Canelo less Mexican, less macho, coming at Golovkin with more variety, creating less obvious angles it might be different. But he knows only one way. They will both see each other coming that’s for sure. May the best man win.