The roper is mounted on horseback with one end of his or her rope tied to the saddle horn by a piece of string. When the calf is released from the chute, the roper will be in hot pursuit with lasso swirling above his or her head. When the loop is thrown, it must pass completely over the calf's head. As the calf pulls away from the rider and horse, the rope grows taut and the string will break away from the saddle horn.