https://medium.com/@Soccermatics/the-offside-algorithm-3285673fd045

The organisers of Robocup were more bullish. After the tournament in 1998 they threw down the gauntlet: “By the middle of the 21st century, a team of fully autonomous humanoid robot soccer players shall win a soccer game, complying with the official rules of FIFA, against the winner of the most recent World Cup.” They acknowledged that their goal was ambitious, but likened it to President John F. Kennedy’s pledge in 1961 that America would put a man on the Moon by the end of the decade. After all, it took only 50 years from the invention of the first computer until Deep Blue beat Gary Kasparov at chess.

Nearly two decades on, how far has robot football come? If you watch videos on YouTube, the situation does not seem promising. They show robots repeatedly walking into each other while the ball lies stationary half a metre away from them; a robot goalkeeper failing to dive as a softly struck shot rolls slowly past it; and players falling over as the force of their own kicking motion overbalances them.