How do you train a horse to neck rein?

Teaching a horse to neck rein is one of the most practical and satisfying things you can accomplish in western horsemanship, because a horse that neck reins correctly gives his rider a free hand — free to rope, carry a flag, open a gate — while remaining fully steerable from subtle rein pressure against his neck. The neck rein is not a separate steering system from direct rein work. It is the result of a horse so thoroughly educated in direct rein steering that he has learned to anticipate the direction the rein is going and respond to the pre-signal of the rein touching his neck before the direct rein pressure is ever applied. Begin with direct rein work and make sure it is solid before you introduce any neck rein concept. Ride your young or green horse in two hands with a snaffle, developing soft, immediate responses to direct rein aids in both directions at walk, trot, and lope before the transition to neck reining begins. The quality of the neck rein you eventually develop is directly proportional to the quality of the direct rein education that preceded it. Introduce the neck rein concept while still riding with two hands by adding the neck rein cue simultaneously with the direct rein cue. When asking for a left turn, apply the left direct rein as normal but simultaneously lay the right rein against the right side of the horse's neck. The horse initially responds to the direct rein and ignores the neck rein, but over hundreds of repetitions he begins to associate the neck rein pressure with the direction that follows and starts responding to it earlier. Eventually the neck rein touch alone produces the turn before the direct rein is ever applied. The mechanics of applying the neck rein correctly matter from the beginning. The rein is laid against the neck — not pulled across it — pressed lightly and directly against the side of the neck at the level of the mane, slightly in front of the withers. The pressure should be the lightest possible contact the horse can feel, applied in the direction you want the horse to move away from. The transition from two hands to one hand should happen gradually and be tested at slower gaits before committing to it at the lope. Test the neck rein at the walk first. If the walk is confirmed, test the trot. If the trot is confirmed, test the lope. A horse that neck reins softly and promptly in every situation at every gait is the product of patience, systematic development, and the willingness to stay in two hands as long as the horse genuinely needs it.