The way that I like to think of a half-halt is to imagine I've build a solid brick wall just in front of the horse's face. The wall moves forward with the horse, and I am in control of how far away from my body I want it to be. I move the wall closer to me when I am collecting the horse, and push it further away when I want to extend or stretch the horse's neck down.
|The moment is captured where the half-halt|
is keeping the horse's balance uphill
The key is that the horse must never touch this wall. If you start to feeling that he is pulling a little long on you, his nose will be pushing onto that wall which means his balance is too much on the forehand and he isn't waiting for you. But also, if his nose is retracting away from the wall and his face is no longer parallel with it, he is behind you and not accepting the contact, so you need to ask him to move towards the support of the wall in front (created by your contact).
It is so true when dressage masters say that you should ride hundreds of half-halts in a session. When I first read that when I was younger I was like "what? How do I fit that many in? That's gonna be a long session with a lot of stop-starting and not much being achieved!" because I didn't realise how to use my half-halt effectively within my work. Because I didn't understand it, I saw it as a separate thing to the paces and movements. But it is absolutely vital to include it in EVERYTHING you do in dressage, because the main thing it does is it helps balance the horse, and without balance, we have nothing.
In dressage our goal is for the horse to be moving uphill and in self-carriage, but the natural balance of a horse is on his forehand, so what do we do to shift that balance back onto the hind leg? We don't pull them back, we don't hold them up, and we don't shake them off the contact... We half-halt. Every 2-4 strides in between half-halts the horse will slowly start to let his balance fall onto the forehand, moving into that brick wall we have put up. This is why we constantly need to check in with where he is in relation to that wall and sit the horse back on his hind legs with a brace of the core and a squeeze with the hand and leg. When he comes back to you on your aid, you must immediately give and push them forward keeping that new balance to keep them in front of your leg and create impulsion and expression. But remember you can't force them to hold that balance, they need to feel they can keep it for a few strides by themselves (hence "self-carriage") until you put in the next half-halt to recreate that balanced feeling.
|The horse must be submissive to the rein and leg|
aids together to create an effective half-halt
If the horse doesn't accept your restraining aids or moves off your leg, feeling a half-halt can be very difficult, so make sure these two things are happening right from the beginning of your session. It's literally stop and go, and then the half-halt is just a bit less stop and a bit less go - whatever it takes to keep him parallel to that imaginary brick wall.