How do I train the drive and circles in the fence work portion of a reined cow horse run?

The drive and circles are the final phase of the cow work in a reined cow horse run, and they follow the boxing phase to complete the judge's evaluation of the horse's athleticism, obedience, and cow sense. In the drive, the horse and rider push the cow down the long side of the arena and then turn it back toward the fence. In the circles, the horse circles the cow in each direction before the run is complete. Each element is scored on control, athleticism, and the quality of the horse's movement relative to the cow, and executing them well requires a horse that has developed confidence and athleticism through the boxing phase first. The drive begins when the rider allows the cow to leave the end fence and then positions the horse to push the cow down the arena wall. The horse should travel parallel to the cow at approximately the same speed, close enough to prevent the cow from turning back toward the herd end but not so close that it panics the cow into a full sprint. A horse that crowds the cow during the drive forces a chaotic turn; one that is too far back loses control of the cow's pace entirely. Turning the cow on the fence — the moment where the cow is pushed into the fence and turns back the other direction — is one of the most athletic and high-scoring elements of the run when executed correctly. The horse must rate the cow's turn and then beat it back the other direction, crossing the cow's path and establishing position on the new side in one fluid movement. This requires the horse to be genuinely fast, reading the cow's intention before it fully commits to the turn. The circles that follow require the horse to drive the cow in a controlled arc in each direction. A horse that is overpowering pushes the cow into a frantic circle; one that is too passive loses the cow's attention and allows it to escape. The ideal circle shows a horse and cow in rhythm, with the horse clearly in control but the cow moving freely.