It amazes me how Clinton Anderson's horses are that sensitive to the hands as Clinton jerks their mouth? I would've thought the horses mouth would become hard and would need to upgrade to a harsher bit because of poor hands.
“Hard mouths” are created when people use hard hards constantly, as in, they pull and hold onto the reins relentlessly without any release. When using -R, a release of pressure communicates to the horse “that was the right behavior”. When you don’t release your reins, your hand signals essentially becomes meaningless to your horse. CA uses escalating pressure, hence why his horses are generally very quick to respond to the lightest of signals. They are afraid of the consequences of NOT responding.