But refusals occur through the riders error in their form.
They look at the fence
They drop their head
They drop their shoulders
They lurch ahead
They drop their horse
They stop riding with their legs
They stop driving through their seat
Their upper body leans forward
Horses jump blindly. They cannot see the fence at all when they are 2/3 strides away from it. When they are on approach to the next fence from landing - the fence is in 2's through their vision.
They need the riders seat, legs, hands, eyes to guide them in the right direction
Then as they get closer, the fence merges from 2, to 1. Now they are locked on the fence. They see it, it is in their head. This is where the distance and the height gets locked in.
Now the riders job becomes that much more important. This is where the rider needs to be tall. This is where the rider needs to not be looking at the fence. This is where the riders seat must be driving, legs wrapped around girth aiding the seat and keeping the impulsion. The riders hands must be carried and supportive. This is where the rider must be behind their horse, with the knowedge and the positivity that they are going to get over.
Now that the horse is 2/3 strides from that fence, they cannot see it. That is why the riders job must be 100% sure. They now turn to their rider for the "YES WE ARE" through their form, aids, eyes.
If the rider, at all - fails in this in any way, big or little - the horse will stop.
Not all horses. There are horses out there who know their job and do it regardless of the countless errors their riders commit on approach to the fence. But there are others out there, who will not.
My TB Gelding, will stop dead in his tracks if I take my leg off him, or if I drop my shoulders.
Top Level riders, from GP to Olympic. Many Trainers - all stress 99% of refusals, faults, veers - are rider error - whether they know it or not.