Why video-assisted referees won’t stop World Cup errors | Tech News

The football tournament kicking off this week is introducing video replays for key calls. Human psychology means some decisions will improve – but some won’t

By Bob Holmes

YOU win some, you lose some. Unless you’re England – then you just lose.

As the 2018 World Cup kicks off in Russia, football fans across the globe are eagerly sizing up their team’s chances. Will it be Germany again? Or dark horse Belgium? Or will the trophy go outside Europe for the first time since 2002?

This year, fans will have someone new to blame when things go wrong: the video referee. For the first time in the World Cup, decisions in all 64 games of the tournament will be subject to review by a team of off-pitch officials watching video footage of the game. Referees are only human, and over the past decade or so we have learned how psychological tics can make decisions go awry. The aim of the new technology is to cut out these quirks of perception. Trouble is, it might end up just introducing new ones.

We love to criticise, but it is hardly surprising that footballing officials make mistakes. They have to follow a fast-moving, free-flowing game and they can’t watch all 22 players at once. But specific effects make some decisions more error-prone than others.

Take offside decisions, the bugbear of many a football fan. An attacking player is offside if they are closer to the opposition’s goal line than the second-last opponent at the time a teammate plays the ball towards them. This sounds simple enough (maybe), but it runs afoul of a visual illusion called the flash-lag effect: …