"The work at the longe line requires all the skill of a good rider; for the longe line holder and the whip holder must know the horse’s conformation and its capacity for change. They have to be able to distinguish faulty gaits from correct ones immediately, to improve the faulty ones and to perfect the correct but insufficient gaits; and they must have a feel for the contact. Specifically, the horse’s character, temperament and athleticism must be evaluated."