Oleksandr Usyk and Tyson Fury rematch for the unified world heavyweight titles on Saturday, live on Sky Sports Box Office.
Their WBC, WBA and WBO championship clash on the Riyadh Season bill will once again be a high-level battle of technical skill and physical prowess. But the mental duel between them will be vital.
Fury typically has a psychological edge on his opponents. But Usyk proved to be a match for him, winning a tight split decision in their first fight earlier this year.
Performance expert James A. King told Sky Sports: "Initially you have to make a lot of assumptions about your opponent in elite sport and that's a skill and ability in itself.
"But once you've had the privilege to have been in the ring with your opponent you've got access to more data. I think it then becomes about who can interpret that best. Who can take the learnings and be most responsive to that experience.
"Then psychology starts to trump technique. It's no longer about getting better. It's about delivering."
It becomes about how they manage their own mindset.
"Even elite fighters like Usyk and Fury are going to experience every emotion under the sun over that 12-week camp coming into a fight like this. Elite performance without pressure doesn't exist. This is about Usyk vs Usyk and Fury vs Fury," King added.
"So what I mean by that is they both have the technical ability to win this fight. I think it's going to come down to who's able to keep it together in the head game and access most of their ability on fight night."
Usyk and Fury are the perfect foils for one another because of their utterly contrasting characters.
"Tyson Fury's just a fascinating individual. A super-extroverted guy. He's a showman, he's charismatic. He's entertaining," King said.
"He's unpredictable, he can see between the lines, he's creative. One of the risks of that is that you can be impulsive and that's something that Usyk might look to potentially capitalise on."
While Usyk is "the complete opposite".
King explained: "He's introverted, he's very balanced, he's not rocked either way positive or negative.
"You certainly wouldn't describe him as a showman, he's quite literal. A lot of yes/no answers. When you ask about his preparation, [he talks about] 'the regime', he likes order, structure, discipline."
Fury has tended to needle previous opponents at pre-fight events. So far, though, Usyk has appeared to be immune to his mind games.
"It's important not to read too much into some of these observations of press conferences at this level. I think for both fighters it's not their first rodeo. I don't think Fury's going to be upset he's not seemed to make him wobble," King said.
"He's talked about what he did well, he's talked about the reality, a split decision, one point [in it], talked about how he didn't focus as much as he could have.
"For me that's a sign the guy's taken ownership, there's humility there. He might not have had a loss on his record before but he's certainly been criticised for performances.
"He needs that adversity, urgency and pressure to see the best of him."
Clearly Usyk managed to perform at the highest level in the first fight.
"He's been on a similar journey to Fury in that his life's been dedicated to this sport, 300+ amateur fights. Olympic gold medallist, World Championship in amateurs, he's travelled the world competing at the highest level. He's going to want to do himself justice and he's got that unblemished record at this stage in his career. He's not going to want to let that one slip," King said.
"I think the obvious one as well is this symbolic representation of physical prowess to his countrymen who will be looking to him for some inspiration and morale."
But that does not mean Fury will be unable to get a revenge win.
"There's an almost mythological spin to this fight. You've got the two extreme ends of the psychological spectrum in terms of the modern warrior archetype in Usyk and Fury. You've got chaos and order," King said.
"Fury represents this chaos and then on the other hand you've got Usyk and Usyk's almost this symbolic representation of order. Stoic, he's almost robotic.
"I think when chaos meets order, sometimes chaos has the edge."
Oleksandr Usyk and Tyson Fury's huge heavyweight rematch will be live on Saturday December 21 on Sky Sports Box Office. Book Usyk v Fury 2 now!
