Describe the correct technique for a rollback from a gallop?

The rollback is one of the most athletically demanding and visually dramatic maneuvers in western performance — a horse that rolls back correctly looks like he has been poured into the ground, pivoted one hundred and eighty degrees on his inside hind foot, and launched back in the other direction without a wasted stride between. Done correctly it is a seamless, fluid sequence that showcases collection, athleticism, and the kind of connection between horse and rider that only comes from correct systematic training. Done incorrectly it is a stumbling, sprawling change of direction that costs maneuver points and puts undue stress on the horse's joints and soft tissue. The foundation of every correct rollback is the stop that precedes it. You cannot roll back correctly from a bad stop, and riders who are struggling with their rollbacks should look first at the quality of their stop before they look at anything else. The horse needs to stop with his hindquarters engaged and underneath him — not strung out behind, not on his forehand, not lurching to a halt with his front feet doing most of the work. A horse that is stopped correctly is already partially organized for the rollback because his hind end is carrying weight and he is balanced over his hindquarters. From a correct stop, the rollback cue comes before the horse has fully settled from the sliding motion. The cue itself involves your inside rein and inside leg working together. Open your inside rein slightly in the direction of the turn — not a direct pull backward, but a leading rein that invites the horse's nose to tip in the direction of the rollback. Simultaneously, your inside leg applies pressure at or slightly behind the girth to ask the horse to step under himself with his inside hind foot and pivot over it. Your outside rein controls the pace and degree of the turn, preventing the horse from swinging too wide or losing his balance to the outside. The horse should pivot completely one hundred and eighty degrees over his inside hind foot, keeping that foot as close to the same spot on the ground as possible throughout the turn. The completion of the turn and the departure back in the new direction should be one motion — the horse pushes out of the rollback back into the gallop with the same energy he carried into the stop. Practice rollbacks initially from a trot or slow lope rather than from a full gallop. The footwork and pivot must be correct at slower speeds before they will be correct at full speed, and fast and sloppy scores worse than correct and slightly slower every single time.