Uefa president Michel Platini has hailed the use of five match officials as a key reason for the improved quality of football at Euro 2012.
An extra official has been placed behind each goal to monitor if the ball crosses the line and has thus far, according to Platini, been a key reason why there has been no scoreless draws in the competition so far.
"How is it that you're seeing more goals scored in this tournament? I think you know the answer: five officials makes things easier," he said, according to Sky Sports.
"With extra officials you're aware of more things: the fear of getting caught is there. There's no more shirt-pulling, players know that the referee is there.
"With five, officials see everything. They don't make decisions without being fully aware.
"There's also a uniformity of refereeing, for example, they don't call unintentional handballs. That uniformity has led to more flowing football."