Horses become incapable of learning when they go past a certain level of fear, anxiety, or stress. This means that if you keep hammering away at the horse, trying to teach them something when they are currently overwhelmed with stress, it will not work.
For the horse, the learning happens on the release of the aid. That means if you don't release the aid, the horse will not learn.
"Don't take the tempo down without revving the engine." ~ Chris Bartle
I don't even think about aiming a young or green horse at a jump until I have them 100% in front of my leg on the flat. If you do, and the horse thinks about stopping, you will have no recourse, and will end up teaching him that
From Facebook fan Joan Dunlap ~ "Fix your position first... then the horse will adjust theirs."