Hi, I tought my horse the "One rein stop" dont think I would do it at a full gallop but at the first steps it works..
I rode a run away when I was younger I took her to a old logging road let her run.. when I tried to stop her she ran harder.. so I enjoyed the ride till she wanted to stop... thats when I took the reins and smacked her and make her run... boy when I pulled to stop she slid.... and never again ran away with me... long time ago.....