How is a working cow horse run structured?

A working cow horse run is typically divided into two or three distinct phases that each evaluate different aspects of the horse's training and athletic ability, with the specific phase structure depending on the class and competition format. In the standard reined cow horse format, the run begins with a reining pattern in which the horse demonstrates its training in the western performance maneuvers — circles in two sizes and two speeds, flying lead changes, sliding stops, rollbacks, and backup — before the cattle work begins. After the reining work is completed, a single cow is released into the arena and the horse and rider have a set amount of time to work it through the boxing phase, the fence work, and the circles. The boxing phase requires the horse to hold the cow at the end of the arena, moving with the cow to prevent it from escaping while demonstrating athleticism and cow sense. The fence work requires the horse to drive the cow down the fence, make a correct turn ahead of the cow, and drive it back in the opposite direction — demonstrating the ability to rate behind the cow, position correctly for the turn, and accelerate to get ahead of it. The run concludes with circles in each direction, with the horse demonstrating its ability to drive the cow in a controlled arc on both sides. Each phase is scored separately and the scores are combined to produce the overall run total, though in some formats such as herd work classes, additional phases are added that require the horse to work from a herd in the cutting style.