Soccer's red card was thought up at a London traffic light

In July 1966 England played Argentina in a World Cup quarter-final at Wembley. The referee, Rudolf Kreitlein, was West German. During the match he sent off Argentina's captain, Antonio Rattín.

Rattín would not leave. He and the referee had no language in common, and the game was held up for several minutes while they argued. Ken Aston, the Englishman in charge of all the referees at the tournament, came onto the field to try to get him off. In the end two policemen escorted Rattín away.

Kreitlein had not made his decisions clear during the game. The next day England's Jack Charlton read in the newspaper that he had been cautioned. He phoned the tournament's press office, where Aston was based, to ask whether it was true. England's manager, Alf Ramsey, went to FIFA to find out what the referee had decided.

Aston kept thinking about it. Later, driving away from Wembley Stadium, he stopped at a traffic light on Kensington High Street. Amber meant stop if it is safe to. Red meant stop. He realized that the same two colors, held up by a referee, could tell players and spectators in any language that a player had been cautioned or sent off.

He had reached for red and yellow once before. In 1947 he refereed a game on a foggy day in London, and the linesmen's flags were in the home team's colors, beige and chocolate. He could not see them in the fog. On the way home he bought a red and a yellow rain slicker at a war surplus store and made new flags out of them.

When he got home from Wembley, according to Aston, he explained the problem to his wife, Hilda. She left the room and came back a few minutes later with two cards cut from construction paper, sized to fit his shirt pocket.

The cards were first used at the 1970 World Cup in Mexico. No player was sent off at that tournament.