The rules in football have become too discriminating. I mean that in the sense that they are trying to get down to a level of judgement that goes beyond human discernment. The game is comprised of speed and violence. This knee down, whistle blew business is very easy for the TV fan to judge with super-slo-mo and multiple angles. The referee is seeing the action in real time, limited vision. Now the coaches throw flags, they review the play and the whole tempo of the game is upset. I find it more and more difficult to watch a pro game with all the "refinements" they have made to the game. Let them play ball.