Many times bobbles happen when working on spins. They happen with broker horses, but are very common in young horses learning the maneuver. In this video is a two year old colt still early on in his training. I've had him just over 7 months and he is a really nice horse by Walla Walla Whiz. The response to these bobbles can be similar at most training levels.
This is a quick video, but I'll go over some things that I want you to notice and see. I'm working on footwork and balance. The reverse arc helps the horse to learn to carry himself in position for the turn. When I ask him to turn, he's in the right position for the spin, and his footwork has a chance to stay right, because it started out right.
Try to see that the horse's footwork has a bobble in it. He steps forward with his left front foot in one of the rotations. Problem there is, there isn't a place for his right foot to go without interference with the left. That causes the hop. I want their inside front steps to be to the side and back some, not forward. Watch it, again, and see my reaction. I just bumped him with my outside foot, then helped him with the inside rein- in that order. Here's why: I don't want him to make excuses for his own mistakes. If he comes out of position and messes up his own footwork, I don't want to help him through that. I want him to see that his mistake has a consequence - more work and discomfort - not from my leg bumping him, but his funky stride can't be easy.
Then I bumped the inside rein. If a horse gets too straight early in their program, that can really mess up their footwork, as well as, their balance. You'll have them on their front end before you know it. There will never be a good pivot on the back end, and it will be sloppy, for sure. When I bumped him with my outside leg, he got a touch straight and looked back toward my leg. I reminded him, once, to stay arched toward the spin.
If everything stays good, which it did, I want to shut that spin off as soon as I can. He's back in position with good footwork and a good amount of effort and speed. With a young horse, like this one, that's the time to get out. I will build the endurance for staying in the spin, longer, once he stays in position, longer, on his own. Nice horse!