Max Baer once described his definition of fear as “standing across the ring from Joe Louis, and knowing he wants to go home early.”

David Haye and Enzo Maccarinelli haven’t terrified as many men as “The Brown Bomber”, but between them they have knocked out forty opponents and plan on adding to that number when they meet on Saturday.

The $2 million dollar fight for four cruiserweight world titles is being billed as the most significant all-British bout in over a decade, with twenty thousand fans expected to fill the O2 Arena in London.

The showdown has been mooted for a couple of years, with Maccarinelli’s knockout of the world-rated Argentine Marcelo Dominguez the catalyst of a war of words between the two camps. The Welshman’s promoter Frank Warren attempted to bring the bout to fruition last year, but Haye rejected the offer, instigating the ill-will.

“I’ve offered David Haye a career high purse to box Enzo Maccarinelli on July 21 [2007] in Cardiff,” wrote Warren in his News Of The World column last year. “The fight was there for Haye but he refused to sign.”

But Haye countered, accusing Warren of changing the contract.

“Warren’s offer was definitely not the highest payday in my career. I’m not sure why Warren would perform such a massive u-turn,” said the Englishman.

The fight seemed even further from realization after Haye’s title-winning stoppage of Jean Marc Mormeck last November.

“I’m ninety-five percent sure [the heavyweight division is] the next thing for me,” said Haye after claiming the WBA, WBC and The Ring titles. “The whole week leading up to the fight my legs felt hollow because of trying to make the weight. I lost thirty pounds of muscle.”

There were rumors that Haye would fight former heavyweight champion Hasim Rahman this spring, but a new offer from Frank Warren and broadcaster Setanta Sports seemed to change his mind.

“I feel that it is my duty as world cruiserweight champion to fight the very best,” said Haye at the announcement of his bout with WBO titlist Maccarinelli.

Despite the apparent awkwardness in striking the deal, there were no signs of tension between the fighters at the initial press conference last December, with both men keen to avoid any trash talk.

Their achievements speak for themselves.

Haye, 20-1 (19), entered the professional ranks after losing a thrilling contest to Cuban standout Odlanier Solis in the heavyweight final of the 2001 World Amateur Boxing Championships. Boosted by exposure on the BBC network, “The Hayemaker” wasted little time in establishing his reputation as a power-punching pro, winning his first ten contests by stoppage inside four rounds.

But his inexperience showed when an over-eagerness to impress against the veteran Carl Thompson saw the exhausted novice succumb to a fifth round stoppage in 2004. Critics questioned his toughness, labeling Haye a “playboy” [his MySpace page features a photo of Hugh Hefner], but a stunning first round knockout of European champion Alexander Gurov silenced most doubters.

A grueling win over the unbeaten Giacobbe Fragomeni and a 105-second kayo of 231-pound Tomasz Bonin preceded his off-the-canvas victory over Mormeck in Paris.

Maccarinelli’s career has meandered a less glamorous path.

Without a strong amateur background, Enzo turned professional to little fanfare, with his reputation taking a damaging blow in only his fourth fight when he was stopped by the 7-9-1 Lee Swaby.

“It was a part of my life where I was doing things that a professional boxer should not do,” admitted Maccarinelli. “I had a talent that I wasn’t doing justice to.”

But uncertainties surrounding Maccarinelli’s desire for the sport were emphatically quashed during his dramatic brawl with former contender Bruce Scott in June 2003. The Welshman was expected to record a relatively undemanding victory, but seconds after the opening bell he was caught cold by the veteran and knocked heavily to the canvas. Yet Enzo struggled to his feet, survived the round, and went on to control the fight with his long thudding jab before demolishing Scott in the fourth.

His fight with the highly regarded Dominguez on the undercard of Joe Calzaghe’s battle with Jeff Lacy was a punishing affair that greatly enhanced Maccarinelli’s standing. Enzo stood toe-to-toe with the thick-necked former titlist before unleashing a devastating uppercut that felled Dominguez in the ninth.

Sixteen months later, in a career-best performance, Maccarinelli produced a well-rounded display to convincingly out-point Wayne Braithwaite last July.

“Maccarinelli is vastly improved,” said former featherweight champion Barry McGuigan after the bout. “We always knew he could bang but tonight he was jabbing from the offset, boxing beautifully.”

An easy fourth round knockout of Mohamed Azzaoui in November precedes this weekend’s long-awaited “Battle of Britain”, and Maccarinelli, 28-1 (21), had nothing but niceties to say about his rival last Christmas.

“I’ve got a lot of respect for him,” he said. “David’s a great champion.”

Haye’s admiration went even further.

“Enzo Maccarinelli is such a big name in the UK,” declared Haye, 27. “There’s no reason for him or me to get angry. Neither of us are guys that scream and shout or flip over tables and cause a scene. I could live in the spare room of his house.”

But in recent weeks tensions have been rising, with Haye reportedly reluctant to partake in events to publicize the fight. Frank Warren accused the Londoner of constantly changing hotels to prevent onlookers from watching him train at his camp in Miami.

“I hear reports from the States that Haye is changing gyms and hotels every few days because he’s concerned that he might be spied on,” wrote Warren in The Sun. “He even refused to tell journalists who went to Florida to interview him where he was staying until the very last minute to avoid revealing any secrets. Talk about paranoia.”

Haye’s secrecy has also led to reports of unprecedented difficulty in squeezing his muscular frame into the 200-pound weight limit.

Conversely, Maccarinelli, who has been preparing with Joe Calzaghe, has appeared relaxed and approachable at his low-key base in south Wales.

“It doesn’t really bother me what anyone says,” claimed the 27-year-old Swansea native. “You’re not going to get a bite out of me. I’m fully confident about this fight and [words] don’t effect me either way.”

But Haye had plenty to say to the media upon his arrival in Britain last week, even branding Maccarinelli’s renowned trainer Enzo Calzaghe a “self-proclaimed great”.

Haye also dismissed speculation that he was laboring to lose weight.

“I’ll make the weight easy, no problem,” Haye told last Tuesday. “My fight before Mormeck was at heavyweight so I had a lot of problems getting down for that fight.

“I literally didn’t think I’d be able to get down to this weight, but I knew after the Mormeck fight that there was a slim chance of this fight happening so there were no celebrations. I was straight back into training camp.”

But Haye’s words haven’t impressed everybody.

“David Haye has not convinced me yet,” former two-division titlist Steve Collins told the BBC. “He has been involved in one or two good fights, but he hasn’t convinced me that he’s a great champion. I don’t think he’s good enough for Enzo Maccarinelli. I could be proved totally wrong but that’s my feeling right now.”

The sportsbooks are currently making Haye a slight favorite, possibly reflecting his greater world-class experience. But another former world titlist has an opinion everyone can agree on.

“I can’t separate them,” says Nigel Benn.

“This one really is mouth-watering. It’s good that promoters are making the fights the fight public want to see.”