Format
The format of the competition was similar to that of 1966: 16 teams qualified, divided into four groups of four playing each other once in a round-robin tournament format. There were no seeds, instead the organizers formed geographical ‘sections’ from which the four groups were drawn in Mexico City, on 10 January 1970. The top two teams in each group advanced to the quarter-finals. However, for the first time in the World Cup finals, teams level on points at the end of the group stage were separated by goal difference rather than goal average (which had been used in 1962 and 1966). If points and goal difference were both equal, lots would have been drawn. If a quarter-final or semi-final match resulted in a draw after extra time the referee would have drawn the name of the team to progress to the next round out of a hat. The final would have been replayed if drawn after extra time.
Sweden became the first country to be eliminated from a World Cup on goal difference when Uruguay progressed from group 2 in second place.
Read more about this topic: 1970 FIFA World Cup