Spain's football academies are called canteras.

Barcelona's is based at Sant Joan Despi, a new complex on the outskirts of the city. The gate into it is surprisingly wide, about 100 feet, like something you might find at the entrance to a factory, which is fitting given the club's production line is the envy of the world.

Ten of the 14 Barcelona players who saw action against Real Madrid in the last April's La Liga encounter were sculpted in the club's cantera. That night only two of Real Madrid's starting XI, Iker Casillas and Alvaro Arbeloa, came through their youth system and a similar ratio applied last night at the Camp Nou in the first leg of the Spanish Super Cup final.

Albert Puig, who has been technical director at Barcelona's La Masia for the last few years, says the most impressive thing about his club's operation is its consistency. Coaches come and go, but the style of football has remained the same since new coach Tito Vilanova's time there as a teenager during the 1980s.

Unlike their Catalan rivals, at Real Madrid's cantera each coach imposes his own vision. Each year there are 60 pupils, 12 of whom are basketball players, the rest footballers. One or two of these will make it as professional athletes with the club.

Barcelona look after their academy players like at a boarding school. Real Madrid has a less hands-on system – the club outsource accommodation and education. There is such an emphasis on education at La Masia that Barca's youths spend, on average, only 90 minutes a day or organised football, plus a match at the weekend.

A notable by-product of Barcelona's inculcation, of its marshalling of a kind of benign military school or what would be called formation in a seminary, is the allure which the club continues to hold over its graduates. The good ones that slip away are often drawn back like prodigal sons, most recently in the case of Gerard Pique from Manchester United; Arsenal's former captain, Cesc Fabregas; and Spain's European Championship hero, Jordi Alba, from Valencia. Three Catalan sons who boomeranged back to Barca once they had become men.

Barca's players don't do physical training until they are 16. It is all ball work. Rondos (piggy-in-the-middle ball exercises) are the fulcrum of the club's philosophy. When you wander around Catalonia, you'll see kids in dusty parks or wherever there's a patch of asphalt playing variations of the game. Whoever's in the middle is the subject of derision – someone to be laughed at.

Every Barça match you watch is an extended game of rondos. Round and round the ball goes. Former player and coach Johan Cruyff is credited in the Barcelona museum with introducing the habit to the club but it has become a staple of training sessions – whether Sunday League or Champions League – the world over. Most Primera Division clubs, even Real on occasion, do rondos for warm-ups before matches. They are a feature of Barcelona's regular training sessions.

If there is an exemplar of rondos, it is Xavi. When he has the ball nestled at his feet, he keeps his head upright and swivelling, like a periscope scouting for a target. The cultured midfielder completes more passes than any other player in the Spanish league, almost twice as many as Xabi Alonso, Real's playmaker. "Barcelona's idea is simple," says Puig. "The training mantra at La Masia is 'receive, pass, offer'. They try to think of where they will make a pass before the ball arrives at their feet."

Not all of their stars can adjust. Thierry Henry and Zlatan Ibrahimovic looked clumsy while playing in Barcelona's colours. Eidur Gudjohnsen, who played at Camp Nou from 2006 to 2009, doubts if the club would be able to fit Wayne Rooney into their system.

Similarly, the Icelander questions whether many from Barca's ranks would cut it elsewhere. "I don't think Pedro, for example, is the best right winger or striker in the world. I don't think Busquets is the best defensive midfielder in the world. I'm not sure Puyol is up there with the best in his position either, but this team are just perfect the way that they're moulded together," he said. "If you put Busquets in a mediocre side in England – or elsewhere – he'd struggle, but together with Iniesta and Xavi that midfield trio works perfect."

Barcelona have a mission to play the way they do. Real Madrid's one-time guru Jorge Valdano says that former coach Pep Guardiola took it "to the point of exaggeration". Real's objective is first to win, then to provide the spectacle. The club use a chequebook in this pursuit. Sport, one of the Barcelona-based sports newspapers, coined the term cantera versus cartera – academy v wallet.

It is naive, however, to think that Barcelona are at the mercy of Real's superior spending power. The Catalans spent £600m over the past decade on players, which is not far off the £870m spent by their nemeses from Madrid over the same period and they outspent Real over the summer of 2011. Indeed, Barça pay their players more, with first-team members paid an average of £101,160-a-week. It pays well to be miserly with possession.

n This is an abridged extract from El Clasico: Barcelona v Real Madrid, Football's Greatest Rivalry. Published by Bloomsbury, it costs £12.99.