It was as though somebody had unearthed a holy relic. Four pieces of screwed-up paper, abandoned on the turf by the away dugout at the Rico Pérez stadium, home of Herculés, who stand 14th in La Liga. The documents that would unlock the secret, unravel the mystery. Four tiny pieces of paper treated with reverential awe.

They were pages torn from José Mourinho's pad. They featured notes such as "pace, movement TR9", "depth, dead balls, switch wings", "arrival, counter". Then there were initials – DM and PL on either side, O and XA in the middle, K behind. And on the final page, numbers: 38, 13, and 6 in a column, 57 below, with "10 months" scrawled alongside. What did it all mean? The relics were carefully gathered up and taken to Canal Plus's flagship show El Día Después. The following day, they were spread across the first two pages of the newspaper AS.

Not only was the substance analysed, so was the style – by a handwriting expert and a psychologist. Apparently, Mourinho's long Ts, round numbers and "vibrant" scrawl show he is a "good man" with an "astonishing capacity for leadership", "a strong, decisive character", and "noble" with "incredible intelligence". As for the numbers, he was surely planning his season: it meant 10 months, 38 league games, 13 Champions League games, six in the Copa del Rey. It was a good sign: he was counting on reaching the Champions League final. That was the theory, anyway.

Few of the faithful doubted Mourinho would succeed. On one side of Spain's great divide – the side he confronts tomorrow night when he takes his Real Madrid team to Barcelona – Mourinho has been painted as immoral, barely better than Beelzebub. But still he occupies their time; never does a day pass without an attack. On the other side, Mourinho is feted, revered, lauded. Everything he does is part of a master plan, a work of genius. He may be Machiavellian but he is a winner.

Last week's red-card furore in the Champions League game at Ajax summed up his season. Real won 4-0 but had two men sent off for time-wasting and incurred Uefa's wrath, as both players thus avoided the possibility of suspension in the first knockout tie. The players and Mourinho have been accused of subterfuge; Madrid's wonderful football lost under a deluge of controversy.

Life in Spain had not started well when Mourinho left Inter early in the summer, having overseen the Milanese side's coronation as European champions. Real drew 0-0 twice in three away games, and many feared that his football would be intolerably boring. His team responded by winning their next three games 6-1, 4-1, and 6-1. They racked up seven straight victories. They are top of the league, a point ahead of Barça, having scored 33 in 12 games. No incoming manager has ever started better in this league.

There is a collective faith about Madrid: watching Angel di María, the expression of Mourinho's methods on the pitch, is to witness sacrifice and unity. Mourinho has built team spirit. He has beaten it into some: Pedro León was left out for two games, Karim Benzema castigated for arriving late, Sergio Canales dismissed with a simple: "I didn't like him." Defensively, they are sound. They play with pace and precision, devastating on counterattacks launched from Xabi Alonso. They are enjoying more possession than his previous teams ever did, too, with quick interchanges led by Di María, Cristiano Ronaldo and the deceptively simple Mesut Ozil.

'This year's galáctico is Mourinho,' Florentino Pérez said. But Sporting Gijón's Manolo Preciado called him a 'scumbag'

It is not just that Mourinho is winning; it is that he is different. That he can do things his way. No Madrid coach has had such authority. Mourinho has brought a seismic shift at the Santiago Bernabéu. Barcelona have often been identified by their coaches; Madrid have not. Until now. The latest edition of the official club magazine says: "Now, the world's best coach is here." At the start of the season, Madrid's president, Florentino Pérez, announced: "This year's galáctico is Mourinho."

Consulted on signings (Ricardo Carvalho and Di María arrived on his insistence), he controls everything and has become the voice of the club, Real's identity. Pérez could not be happier. One director insists: "He is easily the best coach in the world. Not only does he know about tactics, he is the best psychologist, the best manager of egos and the best in the transfer market."

The sports newspaper Marca can barely contain itself: Mourinho, one cover ran, "provokes an orgasmou". Headlines with "mou" in them appear obligatory; some are even calling his team Real Moudrid.

El País called him the "Michael Jackson of coaches". Canal Plus's analysis of his notes bordered on a scene from the Life of Brian. Notes! It is a sign! When Spain's competition committee investigated a confrontation between him and Manolo Preciado, the Sporting Gijón manager, Marca superimposed his head on to Goya's most famous painting, The third of May 1808, which depicts a humble, defenceless Spaniard facing a French firing squad. He was that important.

Not everyone saw him as an innocent victim. Although it was Preciado who insulted Mourinho, calling him a "scumbag", First Division coaches rallied round the Sporting coach. Mourinho had broken the golden rule, questioning another coach's professionalism, accusing Preciado of throwing his match against Barcelona. Preciado is popular; Mourinho has previous, with the constant digs at referees and at opponents.

If in Barcelona they are, as Mourinho insists, "obsessed" with him, he has been equally obsessed with them. It is his mission to destroy them. So far, the provocation is not working. Pep Guardiola refuses to be drawn. Nonetheless, when the Barcelona president, Sandro Rosell, said Mourinho would get the "reception he deserves" at the Camp Nou, most considered it a threat.

And Madrid are more of a threat than ever before. Mourinho's first mission for Madrid came while he was still coach at Inter: to defeat Barcelona in last year's Champions League semi-final. After four trophyless seasons, winning is all that matters. So what if he winds a few people up on the way?

"Those who attack him are just jealous because he is successful," said Alfredo Di Stefáno, Madrid's honorary president. "We didn't sign him to make friends," Emilio Butragueño, the former striker who is now a director, said. "We signed him to win."

And to win tomorrow above all.