Whatever one made of Showtime's Super Six, the quality of one fight in that 168-pound tournament is beyond dispute: Mikkel Kessler v Carl Froch. When they met in 2010, they dueled at a high level in Denmark, delivering a Fight of the Year contender and the best round of that year, a sizzling 12th where Kessler – one fight removed from an embarrassing, emasculating defeat by Andre Ward – found his inner man and traded shots with boxing's most fearless warrior, eventually coming out on top by decision.

It wasn't Froch's finest moment. After the defeat, he whined endlessly about the decision and made excuses, claiming that a volcano in Iceland that had threatened to postpone the fight took him out of his mental game. The victory was Kessler's finest moment, as he had rebounded so impressively from such a low against a fighter who has gone on to become one of the world's 10 best. Since that night, Kessler has endured a long layoff due to an eye injury and won two ambiguous stoppage wins. Froch has lost to Ward, then secured the victory of his career over Lucian Bute.

That's the backdrop to this rematch, one of the most anticipated bouts of 2013. The promotion has had its share of volcanic moments. This week Froch threatened to "kill" Kessler if it was necessary, even though the pair have become buddies outside the ring. It earned him a reprimand from the British boxing authorities, but it wasn't so long ago that Kessler said there would be "death in my eyes" for Froch.

Such rhetoric hardly elevates boxing but, if nothing else, it reveals the mindsets of both men. This fight is, figuratively if not literally, do-or-die for both of them. Froch is the kind of boxer who harbours grudges against the universe for any perceived wrong, and it fuels his enormous will. Kessler is seen to be over the hill and he needs this victory to cement his legacy. Such passion and such history are the stuff of great rivalries.

This fight probably wouldn't appear on HBO if the network didn't see the winner as a viable opponent for Ward, an HBO favorite owing to ex-Showtime executive Ken Hershman taking over HBO's boxing programming. But the fight has appeal and competitive merit independent of Ward.

Perhaps Froch has learned from his defeat to Kessler, even if he never considered it a loss. In his very next fight, against Arthur Abraham, he displayed defensive aplomb and versatility that we had never seen before. The Ward loss was a setback, but an understandable one; Ward is special and Froch is just a notch below that.

By the time Froch fought Bute, he was back to his old ways, multiplied by 10. The nuance of the Abraham performance was gone, replaced by his traditional "I don't care how much you hit me, I'm going to get mine" mentality. Bute caught him with some enormous shots, but Froch, whose chin is as good as they get, strolled through them and broke Bute's heart before shattering his consciousness. If there were any Froch non-believers before the win against Bute, they were converts after it.

In some quarters, Bute was considered too fast, too powerful and too cute for a man of Froch's limited means. But Froch's whole career is a testament to how much willpower and the ablity to absorb punishment overcomes any limited means. He is coming off a fairly easy bout against Yusaf Mack, following a long and grinding schedule, which continues its grueling pace on Saturday.

Froch's momentary lapse of will against Kessler came at a time when Kessler's shaky psyche was at its most stable. Ward's physicality and technical superiority had Kessler on the verge of quitting before a wound forced the bout to the scorecards. This wasn't the first time Kessler had shown mental weakness. He fought well against Joe Calzaghe, but Calzaghe mauled him psychologically as much as he beat him physically. Kessler went into some kind of hiding after that, ducking the powerful but limited Edison Miranda.

In the aftermath of the Ward defeat, Kessler hired a sports pyschologist to rehabilitate his mind. It worked, apparently, because, as close as the Froch win was, it wasn't the theft Froch has since made it out to be. Maybe Froch would have won the decision in Nottingham but, on neutral soil, Kessler probably would have won it just the same.

Kessler disappeared for more than a year after that fight due to an eye injury, and then rattled off three consecutive stoppages. The win over Allan Green showed the best and worst of Kessler, as the talented but fragile Green knocked him down in the first round to suggest he wasn't all physically there, only for Kessler to rally and stop Green in the fourth with a Knockout of the Year candidate in 2012. He wasn't troubled at all by the shopworn Brian Magee – and you could throw Green in that category as well – but both fights showed that Kessler, aging or not, was again sitting down on his punches and trying to knock fools out.

That's why you can't dislike this match-up. Although only 34, Kessler has picked up injuries over the years and his reflexes are not quite what they once were. He appears older than 35-year-old Froch, but he has made up for that decline in a few ways. Once a strict 1-2 artist – and a beaut of one at that – Kessler has become a well-rounded fighter. He is more responsible defensively and does knockout-level damage with a straight right to the body or a left hook.

The timid boxer we saw before has been replaced by someone who wants to gun for the KO and has the wherewithal to get it. Froch has a heroic ability to absorb punishment but, when Kessler sets his mind to it, he is an enormous puncher. Ward was accumulating stoppage-level damage against Froch before he hurt his hand, thanks to accuracy, and his punching is nowhere near the level of Kessler's.

Froch, meanwhile, has broadened and expanded his repertoire, yet at his core remains Carl Fucking Froch: an unbreakable stone tablet of a man who will take on the best boxing has to offer while only barely registering that they're hitting him tremendously hard.

You can see why Froch is the favourite. You can also see why Kessler is a not-unpopular upset pick among boxing fans and writers. The only thing we know for sure is that the fight will provide tremendous action. If anyone can knock out Froch, it's Kessler. If anyone can knock out Kessler, it's Froch.

Froch has added the right number of wrinkles to make his kill-or-be-killed mentality even more dangerous, but he was at his best against Bute when he decided that no matter what was thrown at him, he would be right in the chest of the Romanian-Canadian.

Froch has 18,000 fans to please and, if he is overeager, Kessler could walk him into something fatal to his consciousness – as hard as that is to imagine based on Froch's unbreakable nature to date. Kessler could outbox Froch over 12 again. More likely, Froch, with home advantage, improved technical ability and less wear and tear, can outwork Kessler. Even more likely, Froch will stop Kessler late in the fight.

Froch can be beaten – and has been twice, if not three times (Andre Dirrell) – but, when he has this kind of near-psychotic focus, it becomes hard to see how he can be bent, let alone broken. This fight is as good a match-up as they come. Kessler was admirably brave to take it on, but by Saturday night he will be asleep and dreaming of happier days in Copenhagen.

• This is an article from our Guardian Sport Network

• This article first appeared on The Queensberry Rules

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