Hi, I’ve seen a lot of great suggestions here, like the “follow the leader” exercises and throw-out classes. I have a very similar horse, he is a QH and is mainly a speed horse. I full lease Harley and he used to want to race everyone. Over the past year I figured out how to fix this problem.
1st I went to groundwork, I made sure he respected me, which it turns out he didn’t, I worked with him on mostly showmanship after every ride for a week, and our rides got so much better! we even do halter-less showmanship now. Now I decided to work on the problem at shows. I made sure he was calm and collected in the warm-up arena did lots of circles and made sure he flexed and was round and listening. Then sign up for a throw-away class. Every time he misbehaved (I would stay near the center to avoid hitting anyone) I anchored my hand to my knee and turn him into a tight circle until he gave to the pressure and listened. Then we would go right back into what we were doing and repeat until he understood which usually only took 2/3 times, not much. He was fine the rest of the day. I know it’s embarrassing, but it had to be done. And now he respects me fully and we don’t have to deal with that anymore. He is a perfect, hardworking little angel 🙂