When Zinidine Zidane head butted Italy's Marco Materazzi in the 2006 World Cup Final, a glittering career came to an ignominious end.

As the elegant Frenchman, head bowed, walked past the gleaming World Cup trophy for the very last time, the actions taken that day would result in the greatest revolution the sport had ever seen. The actions taken, not by Zidane, but by the team of match officials charged with officiating the world's greatest sporting event.