Kevin McCarra argues that the really fascinating aspect of Chelsea's Jose Mourinho lies not in what he does as a manager but in the impact that it has

There was no risk Jose Mourinho would meet with the "Arsene Who?" style of headline that greeted his Highbury counterpart in 1996. The Chelsea manager had introduced himself to English minds by knocking out Manchester United before taking the Champions League with Porto. Nonetheless, the widespread assumption he would adapt instantly to the Premiership was unprecedented.

At Stamford Bridge especially they had been disappointed in the long run with their foreign coaches, and Ruud Gullit, Gianluca Vialli and Claudio Ranieri were sacked. While building the five-point lead that must be protected at Arsenal tomorrow, he has shown himself to be of a different calibre to his predecessors.

He only became a manager in his own right for the first time at Benfica in September 2000. He was building knowledge and opinions long before he began to accumulate experience. "More time to study," he says when asked about an abortive playing career. Mourinho, poring over manuals and statistics, gives nerds a good name. Roger Spry, a fitness expert who has known the Chelsea manager for almost 20 years, points out that Arsene Wenger and Carlos Queiroz, Alex Ferguson's right-hand man at Manchester United, made no impression as footballers.

"The three of them are highly educated and you wonder how many languages they can speak in total," said Spry. "Jose has all the Brazilian and Argentinian coaching literature available to him and it has never been translated into English."

Mourinho still has a magpie mind. "I look to everyone," he said yesterday. "It wasn't just when I was young and had no CV behind me, but even now. You have to try and study everyone who is involved in football."

The manager considers himself, as he put it in Portuguese, a grande cabeca (big brain) in the modern school of football thought. He draws no distinction between fitness work, coaching and advancing players' knowledge of the game. "Jose's training the mind and the body all at the same time," said Spry. "The drills they are given are never mindless."

There is a common sense underpinning Mourinho's outlook. He, however, seems more intense, more likely to instil his schemes into the minds of his players. He is habitually termed arrogant but he knows all too well that the demands on a coach to make an impact is forever urgent. He has admitted he saw his father Felix being sacked "too many times".

It may be a reaction to that experience that makes Mourinho so thorough, although Spry argues there is nothing unusual about his habit of keeping a "bible", a running record of every football experience. Similarly the Chelsea manager is following standard practice in having an assistant, Andre Villas, prepare a report on each opponent.

There can be undue awe about the manner in which Mourinho goes about his duties. The really fascinating aspect lies not in what he does but in the impact that it has. Luis Lourenco, whose biography of Mourinho is published this week, believes the references to the manager's IQ are inadequate. "I don't think it is a question of being more intelligent," he said. "The word is perception."

The acuteness of Mourinho's insights is one of his main advantages and, for instance, his reshaping of his Porto team during the Champions League final unleashed a counter-attacking style that took them from a 1-0 lead to a 3-0 rout of Monaco. If he is to be sure of that responsiveness, the manager has to eradicate distractions. He had no compunction about dispatching the most globally renowned players at Chelsea, Juan Sebastian Veron and Hernan Crespo, on loan deals.

Despite the rise in its reputation, he gives the club the feel of a neat, well proportioned operation. The restriction of the squad to 23 players enriches the manner in which people can deal with one another. "I guarantee he will treat every one of them with respect," said Spry, who also worked with Wenger at Monaco and sees the similarity with Mourinho. "He and Arsene have got their own personalities but their approach is similar. They're hyper-intelligent and they make every player feel special."

Of course, Mourinho can also make an individual feel unwanted. At Benfica he dropped the most popular player, Sabry. When the Egyptian complained to journalists, the manager told them how often Sabry lost the ball, how rarely he recovered possession and referred to the eight minutes and three boot changes the sulking playmaker had needed before coming on as a substitute.

"It was courageous," says Lourenco. "You have to remember that it was this first time in his life he had been the main coach and he had just arrived at the great Benfica. Another guy would have been scared to face Sabry. Mourinho - no."

The manager was scathing then. Joe Cole has not been guilty of misbehaviour but he knows how much his boss detests Sabry-like selfishness. The midfielder scored Chelsea's winner over Liverpool in October but all Mourinho wanted to talk about afterwards was how little Cole had done for the team subsequently.

Mourinho emphasises the group rather than the individual in his recruitment. He caused unrest at Porto by bringing in unheralded players he had used at Uniao Leiria. The fans were dismayed by the arrival of Derlei and Nuno Valente but would eventually idolise them. "His preference is for young players who are very ambitious," Lourenco said. "That's what he wanted to do at Chelsea."

In keeping with the theme, it seems inevitable Mourinho will again try to buy Steven Gerrard in the summer. The fee would be mountainous but the midfielder still fits the bill as an individual with plenty yet to achieve.

When Ferguson commented on the complete lack of former Premiership winners at Chelsea he thought he was pointing out a weakness. Mourinho will see it as a strength. In one sense, this is an easy phase for Mourinho. He has a compliant and focused squad but life will alter if all goes to plan. A man such as Arjen Robben, for instance, could turn into a global star and, as David Beckham has shown, fame has a gravitational force that can warp a club. Whatever happens, the manager will not falter. On his first day at Porto he predicted, correctly, a then derided club would win the next league title. Such comments are part of his calculated brashness.

The manager has been able to involve Roman Abramovich in the life of the dressing-room while at the same time demonstrating Chelsea are not a billionaire's bauble. Mourinho himself is enamoured of the English passion for football and despite his innovations he has brought an old-fashioned seriousness to Stamford Bridge. Where Ranieri played down Chelsea's chances in the Premiership, his successor will not leave his men with the luxury of an excuse.