alienat3d
easy-going alien grinder
Bronze Level
Speaking strictly about boards with two instances of a card, not three.
I notice that no poker strategist ever discusses the possibility of the opponent having quads in these positions. I also noticed that I myself don't think I've ever put an opponent on this hand. Quads are just too rare to ever fold under the assumption that you're beat by them. Have you ever done it?
You asked and then you answered it already by yourself. Never, as Quads are just too rare. I would rather put my opponent on higher Full House, than Quads really.