How do you ride with a bosal and how does it work?

The bosal is one of the oldest and most elegant pieces of horsemanship equipment in the western tradition, originating in the vaquero horsemanship of California and Mexico where it was used as the foundational training tool for developing the finished bridle horse through a patient systematic progression that prioritized lightness and willingness above all else. The bosal is a braided rawhide nosepiece that encircles the horse's nose and jaw, held in place by a headstall and balanced at the back by the mecate — a rope made from horsehair or mane hair that serves simultaneously as the reins and the lead rope. The bosal works through pressure on the nose and on the jaw beneath the chin — a squeezing action that the horse releases by softening through his poll and jaw and bringing his face toward the vertical. Unlike the snaffle which works through direct side-specific mouth pressure, the bosal works through nose and jaw pressure that is more diffuse and less directional, which is why the horse must have a solid foundation of lateral yielding established in the snaffle before the bosal's communication makes clear sense to him. Riding with a bosal requires two hands in the early stages, with the reins held so that opening one rein creates pressure on the corresponding side of the nose while the other rein remains relatively passive. The release is the reward — the moment the horse softens through his jaw and poll in response to the bosal's pressure, both hands soften and the pressure releases completely. The timing of that release is the entire lesson. The weight and stiffness of the bosal are calibrated to the horse's stage of training. A young horse starting in the bosal uses a heavier stiffer bosal that he can feel clearly. As the horse advances and his responses become lighter, progressively smaller and lighter bosals are used — the pencil bosal of the finished two-rein horse is so light that its communication is nearly invisible, which is the point toward which the entire progression has been building. The mecate is tied to the bosal in a specific way that allows the reins to be adjusted for length while the tail of the mecate is coiled and tucked into the belt as a lead rope. The feel of the mecate through the bosal is softer and more following than a leather rein through a bit, and developing the feel for bosal communication requires a specific attentiveness to the horse's jaw and poll that riders accustomed to bit work find initially unfamiliar.