What qualities make a horse a good Hunter Seat Equitation mount?

The qualities that make a horse well suited for Hunter Seat Equitation center on reliability, consistency, and trainability rather than exceptional movement or athletic brilliance. Because the rider is being judged rather than the horse, the horse's job is to make it as easy as possible for the rider to demonstrate correct, effective position. A horse that is easy to rate at consistent paces, picks up leads quietly and correctly, maintains its rhythm through turns and lines, and adjusts its stride readily to the rider's requests allows the rider to focus on position rather than horsemanship problem-solving. Temperament is the most important quality. A horse that is anxious, spooky, or resistant forces the rider to compensate with position — gripping with the leg, bracing with the hand, or altering upper body position to manage the horse — all of which are visible to the judge and result in lower scores. A horse that is too much horse for the rider's current skill level will always produce a worse equitation performance than a simpler, less talented horse that the rider can sit quietly and correctly. The horse must also be comfortable and adjustable between distances at the canter and over fences — an equitation horse that always arrives at fences on an awkward distance makes it very difficult for the rider to jump with correct position regardless of skill level. Scope and movement are secondary considerations, as they are not what is being judged, but a horse that moves and jumps with reasonable quality allows the rider to demonstrate better position than one with very rough, difficult movement.