The allowing hand is a hand that in no way restricts the natural movement of the horse’s head and neck.
The allowing hand is a hand that allows the horse to go forward and does not restrict the natural movement of the horse, yet the hand that is still allowing has got to be able to give indications for direction and to give indications for pace and speed.
The word “allowing” is referring to the state of the hand or the influence of the hand.
There are two ways of making a downward transition or slowing the horse down:
One is to indicate with the outside rein and then allowing the horse to respond to your aid to slow down or go down to a lower transition.
The other way is to have a non allowing hand and this non-allowing hand prevents the horse from remaining at teh speed he is already in and so he has to slow down.
The second way of slowing down the horse is incorrect.
Most people, when they slow down the speed or go from canter to trot and particularly from canter to trot and walk to halt, cease allowing the complete the last few strides of canter or walk, because of the non-allowing hand but in the canter and the walk, the horse nods his head with each stride.
The horse must be allowed to continue the complete nodding of his head until he has finished the last stride.
So, within the contact that the rider has with the horse’s mouth, he must give the indication through the reins to slow down - and come down to a lower transition or pace - without interfering with the natural movement of his head. In other words the rider must allow the horse to complete his last steps of canter or walk.
When you give an aid to your horse you give the indication, now you have got to wait a moment for his reply: this is a question and answer game.
You ask him a question and it depends on his reply what you do next.
If you are not aware that the horse is able to ask questions, you never have the real understanding.
When you train a horse for a length of time, a real long time, one rider, one horse, the relationship one has with the horse when riding is quite amazing and it is a discussion.
The rider and the horse have a conversation throughout the whole of the lesson but very few riders are aware that the horse is requesting certain things from the rider.
Robert Hall (trainer of the british olympic dressage team for the stockholm, rome, and tokyo olympics) (via maplewoodsporthorses