Why does Clinton Anderson teach mounting from both sides and how do you train a horse to accept it?

Clinton Anderson teaches mounting from both sides — both left and right — as a standard practice based on a straightforward argument: a horse that can only be mounted from the left is only half trained, and there are many practical situations where mounting from the right is necessary. A horse that has only ever been mounted from the left will show the same resistance on the right side that an untrained horse shows on the left, because it has simply never been taught that context. Historically, horses were trained to be mounted from the left because mounted soldiers carried swords on their left hip and needed to mount from the left to avoid entangling the sword. That practical reason has been irrelevant for well over a century, but the tradition persists — and Anderson teaches that perpetuating it without reason produces a one-sided horse. The training process for right-side mounting follows the same sequence as left-side mounting: put weight in the right stirrup progressively, ask the horse to stand without moving, swing the leg over slowly. A horse that shows concern from the right side needs the same systematic desensitization from the right — rubbing with the saddle pad from the right, tightening the cinch while standing on the right, putting weight in the right stirrup gradually — that it received from the left during initial training. Anderson notes that horses trained to mount from both sides from the beginning require no extra work — the symmetrical approach is simply part of the normal training sequence. Horses that have only been mounted from the left for years may take several sessions to become as comfortable from the right, but the process is the same.