What happens when a competitor breaks the barrier and how does it affect the overall score?

Breaking the barrier is one of the most demoralizing mistakes a competitor can make in working cow horse because it penalizes the run before it has truly begun, and no amount of brilliant reining or exceptional cow work can fully overcome the deficit it creates. The barrier is set to give the cow a predetermined head start before the horse leaves the box, and crossing the barrier line before the cow clears the chute results in a fixed penalty that is added to the final score regardless of what the horse does afterward. In a discipline where classes are often decided by fractions of a point, a barrier penalty is frequently the difference between first place and the middle of the pack. The cause of barrier penalties is almost always a horse that has become anxious in the box and begins anticipating the run before the cue is given. A horse that is watching the cattle chute intently, tensing through its neck and back, and beginning to shift its weight forward is a horse that is on the verge of breaking the barrier on its own initiative. Once that pattern is established it becomes self-reinforcing — the horse learns that gate movement means go, which means it is leaving on the chute rather than on the rider. Preventing barrier penalties requires training the horse to respond to the rider's cue rather than to environmental triggers. Practicing the box routine repeatedly — entering quietly, standing still through various sounds and movements around the chute, and leaving only when the rider asks — builds the habit of waiting for the correct cue. Varying the routine during practice so the horse cannot predict when the run will begin keeps it attentive to the rider rather than the environment. A horse that has developed a barrier problem needs box work done away from cattle entirely, rebuilding the association between stillness in the box and waiting for a specific cue before any movement is rewarded.