Shortly after the1994 World Cup, Jack Charlton said that he thought full-back was the most important position in football. When 4-4-2 met 4-4-2, he reasoned, the two centre-backs picked up the two opposing centre-forwards and the four midfielders cancelled each other out, leaving the four full-backs as the players with the time and space to affect the broader shape of the game.
That is perhaps even truer now. Full-back is the player whose role has changed most since names began to be given to positions
