At least one forward would hang close to the opponent's goalkeeper, guarded by a defender. Teams would be spread in length over the pitch. There will probably b

At least one forward would hang close to the opponent's goalkeeper, guarded by a defender. Teams would be spread in length over the pitch. There will probably be many special strategies. Maybe everybody would be in the box when the other goalkeeper kicks the ball. That's prevented by offside now. BTW offside works only in the opponent's half of the pitch.