If you've watched any of the televised World Cup matches, you'll have glimpsed the new technology being used by the VAR (video assistant referee) to help determine when a player is offside.
Though it usually appears on the TV screen for just a few seconds every match, it's arguably one of the stars of Qatar 2022.
Semi-automated offside technology (SAOT) has taken decades to develop, requires sophisticated artificial intelligence (AI) systems, a battery of special cameras, as well as a ball packed with sensors, and about 10 years ago would have seemed impossible.
