[cuppett777]

I understood you I just think we may need a referee ruling. If the ball breaks the plane of the goal line at any point it is a TD at that point, nothing else matters. But in the field of play, if a player extends the ball past the 1st down marker, but his foot goes out of bounds behind the marker, I think he is out of bounds where his foot goes out and it isn't a first down. In the same way, you can run beyond the marker, then retreat behind it and if you are tackled or go out of bounds, you are considered short of the 1st down.

you are correct, it happen when Arkansas State played WKU few weeks back,Wku had the ball reciever holds ball out for the 1st down,refs go back and review it and his knee hit the ground as he was extending for the 1st down,it would have more than like got them the win, but booth overturn it cause knee was down 1st..