What If We Had Perfect Robot Referees?

Last month, Mark Clattenburg, who is generally regarded as one of the finest referees in professional soccer, left England's Premier League for a better-paying position in Saudi Arabia. Plenty of famous players have chosen riches over prestige and joined less established leagues in Asia and the Middle East. But this was one of the first times that a referee of Clattenburg's stature and prominence had left in his prime. Just last year, he was selected to referee two of the most important matches on Earth: the finals of the Champions League, in May, and then the European Championship, two months later--plum gigs that testified to his skill. To commemorate the occasion, he had the feat tattooed on his arm--a testament to his knack for preening.