From goal average to goal difference -------------------------------------
To avoid drawing lots or playing an extra match when two teams finish with the same number of points, the original idea was to separate them using the "average of goals" — a term for which French often borrows the English phrase goal average — that is, the quotient of goals scored by goals conceded.
This method favors defensive teams, since a smaller denominator inflates their average. Faced with the low number of goals scored, and to liven up matches, the formula was changed during the 1962–63 championship season with the introduction of "goal difference."
This may have been mere chance, but at the end of the previous championship, Stade de Reims and Racing Club de Paris had finished the competition with 48 points each, and it was the Reims side that won on goal average. Under the new method, it would have been the Paris side — level on goal difference — that was crowned champion (they had scored more goals), thus depriving Stade de Reims of a fine European run.
More recently, in Group A of the 2014 football World Cup, Brazil finished ahead of Mexico on goal difference, with 7 goals scored against 2 conceded; on goal average, Mexico, having scored 4 goals but conceded only 1, would have come out on top.