Those eggheads who regard football as chess on wheels can rarely have relished a match so much as the meeting of managerial minds that takes place at Highbury this afternoon. Has there ever been a domestic fixture in this country contested by opposing coaches with such a scientific approach to their trade as Alsace's Arsène Wenger (nickname: "The Professor") and Setubal's Jose Mourinho (favourite word: "methodology")?
When the ascetic Wenger arrived here in 1996, he was not so much eight years as light years ahead of the prevailing culture. In those crazy, hazy days, a bender was a drinking session, not a curling free-kick; sophisticated dietary habits comprised no longer eating steak as a pre-match meal; and Arsenal's captain had just come out as an alcoholic, which was two fewer addictions than one of his team-mates was admitting to. "I feel like Marge Proops with you lot," poor Bruce Rioch had said shortly before being relieved of his duties as their manager.
Fortunately for Mourinho, Continental culture kicked in at Chelsea at about the same time. Unlike the little-known Wenger, who did not immediately win over his new charges, he also arrived with a reputation to command universal respect among the squad, who were therefore all the more receptive to the minutely detailed training, preparation and tactics that have propelled them five points ahead of the champions.
So Chelsea will unquestionably be better prepared today than for any of Claudio Ranieri's duels with Arsenal over the years, which produced so little joy for west London until that epic second leg of the Champions' League quarter-final last April. The defeat inflicted that night by goals from Frank Lampard and Wayne Bridge after Arsenal had led at the interval remains possibly the most bitter one suffered in Wenger's time here, slamming the door just as a path was opening up to the easiest last four in memory in the competition he desperately wants to win.
Before that, Wenger's team beat Chelsea once without Patrick Vieira (2-1 at Highbury in the Premiership, when Carlo Cudicini dropped a brick, and the ball) and once without Thierry Henry (in the FA Cup, after Jose Antonio Reyes scored two second-half goals). This time, however, the absence of their captain looks critical, all the more so since the Brazilian pair Edu and Gilberto Silva are still injured. That puts an awful lot of responsibility on the young shoulders of Francesc Fabregas, 17, and Mathieu Flamini, 20, who will be up against a compact Chelsea midfield trio of Claude Makelele, Lampard and Tiago.
"I feel they will do well," Wenger insisted after training on Friday. "They are highly competitive, two winners, who have the physical stamina to cope. Flamini has the aggression, Fabregas a little bit more the technique, so they complement each other well. Flamini is in his first year here, but is used to Marseilles, where the pressure is like Arsenal and they attack your car if you don't win. But it's up to us to get Chelsea to play how we want them to play, to our strengths. They have a game basically based on protection of the centre."
If that is the defensive strategy, Mourinho's plan in attack has come to revolve around the increasingly fashionable use of two wingers with a single striker, who, unfortunately for Eidur Gudjohnsen and his many admirers, seems likely to be Didier Drogba. It is not one that has ever appealed to the equally cerebral Wenger, which makes the tactical battle this afternoon all the more intriguing: "I feel that you are just playing with one striker less and when you have the ball you have only one player up front," Wenger said. "They can do it because Drogba is a physical force, but I always prefer to play with two strikers because it makes the game more balanced and we have a player like Dennis Bergkamp who can play the role of the second striker.
"There are many different trends in the game. When I arrived here many people said, 'Oh, it's old-fashioned to play 4-4-2 now, we play with five at the back', which just came out of the World Cup, but it always comes back to what is rational. With 4-4-2, you have 60 per cent of the team on 60 per cent of the surface, plus two, two and two in the centre. Basically it is what suits the occupation of the field." And you thought it was a simple game?
Those who prefer to concentrate on the personalities involved will have found much to engage their attention this past week, although for Wenger, "What the managers say or don't say is not the most important thing". He could still not quite resist what sounded, amid a rather cool appraisal of Mourinho's achievement at Chelsea, suspiciously like a little dig: "I'm not surprised he's adapted well, because it was a team already doing well. It's not like he took a team over that's never done well before and finished 17th in the championship. They finished second in the League last year, so if you invest however much they did, it is normal that they now fight for the championship."
Five points ahead of Arsenal, they are certainly doing that, largely because of results against the other leading contenders. Six games in the mini-league involving Arsenal, Chelsea, Manchester United and Liverpool last season brought Wenger's side 14 points, Chelsea seven, United and Liverpool six each; and the teams finished in precisely that order.
This season's pattern, however, shows where the champions have fallen down, losing both matches so far, to United (2-0) and Liverpool (2-1). Chelsea, in contrast, have beaten the same sides, both by 1-0 at a time when they were playing more constricted football and had not touched the free-scoring heights of recent weeks. Even at that stage, Mourinho knew the importance of winning against closest rivals. Brought up in what is effectively a three-team Portuguese league of Porto, Sporting Lisbon and Benfica, he claims never to have lost any of those games; and does not intend to start this afternoon.
Benni McCarthy's late header for Porto last Tuesday notwithstanding, New Chelsea could hardly be in better shape for their first such test away from home. A headed goal at the far post may have exposed one of the few weaknesses in the side - the lack of height shared by Bridge and Mourinho's preferred left-back, William Gallas - but it is not an area Arsenal are equipped to exploit. Chelsea can recall Makelele, Tiago and Arjen Robben today; indeed, had the manager not had such personal motivation to do well in the Estadio Dragao, he might reasonably have kept far more players fresh for this afternoon.
Steve Clarke, standing in at the pre-match press conference in Portugal, which the manager ducked out of for diplomatic reasons, trotted out the usual cliché about taking one game at a time, but Mourinho has never done any such thing, always thinking one move ahead - and normally one ahead of the opposition. For the best part of a decade, any Premiership manager has to be up early to outthink Wenger. Today and in the years to come we will discover whether Jose Mario Santos Mourinho Felix is an early bird as well as a wily one.