The president of the European champions is addicted to expensive footballers. But his predilection often harms the club and the players themselvesSign up to Soccer with Jonathan Wilson herePeople will tell you there’s no such thing as club DNA. How could there be? The managers change, the players change, the directors and backroom staff change. So how can a club have a distinctive identity? How can Spurs be Spursy? How can Bayern have Dusel? Why are Ajax still be banging on about playing the game the right way?Often it makes little sense. A mood transmitted from the fans, perhaps? A culture passed on from player to player, director to director? Something in the very air around the stadium? But occasionally there are times when it’s perfectly obvious why a club is the way it is, why it is apparently locked in a cycle of otherwise inexplicable behaviour. Real Madrid act like Real Madrid because the club’s president is, as he has been for all but three years since 2000, Florentino Pérez. And there is nothing Pérez likes more than a famous, expensive footballer.This is an extract from Soccer with Jonathan Wilson, a weekly look from the Guardian US at the game in Europe and beyond.