I suspect disallowing all upper body contact would lead to more goals. Posting a defender on the goal line would be less effective. > There would probably be q

I suspect disallowing all upper body contact would lead to more goals. Posting a defender on the goal line would be less effective. > There would probably be quite a bit more acrobatics involved to handle the ball being in the air. I think that could end up being disallowed, too because of the risk of feet hitting heads, especially inside the penalty area. Think of the body movements of https://en.wikipedia.org/wiki/Sepak_takraw https://en.wikipedia.org/wiki/Sepak_takraw but without the net separating teams.