The chief changes in the football rules for the season of 1912 may be outlined in a few words, although their effect on the play will be considerable. The principal alteration was the addition of an extra down. Instead of three trials in which to advance the ball the specified distance of 10 yards, four are allotted.
The field has also quite materially changed. It was formerly 330 feet long. The goal posts have now been brought in so that the distance from one goal line to the other goal line is now 300 feet or an even 100 yards, but behind each goal the extra space, 10 yards, thus cut off is retained for the purposes of the forward pass; that is, a player may receive a forward pass in this end zone and it will still be legal. The kickoff instead of being made as formerly from the middle of the field, the 55-yard line, will now be made from the 40-yard line of the side that is doing the kicking.
Another change of importance is that on the kick-out the opponents, instead of lining up on the 25-yard line of the opponents' goal, line up on the 20-yard line, and the ball must be kicked from some point behind that 20-yard line.
The restriction that the forward pass should not go over 20 yards has been removed and a forward pass of any distance is legal. The on-side kick has been cut out altogether; that is, a kicked ball striking the ground does not put the kicker's side on-side. The balance of the changes are of lesser importance.