That’s not the way it worked. In ‘73, a Class A school got 3 points for beating a Class A opponent, 4 for beating a AA, and 5 for beating a AAA school.
Class AA schools got 2 points for beating an A, 3 for beating a AA, and 4 for beating a AAA.
Class AAA schools got 1 point for beating an A, 2 for beating a AA, and 3 for beating a AAA.
The one team with the best point average in their respective class from each of the four districts made the playoffs. The following year (‘74) a team that played 10 regular-season games could make one of those a scratch game if the opponent was in a higher or lower class. If you won (or lost) you didn’t get the points, but your total point sum was divided by 9.