More than any other event in professional rodeo, tie-down roping has roots dating back to the Old West. When a calf was sick or injured, it had to be caught and immobilized quickly for treatment. Ranch hands prided themselves on how fast they could rope and tie calves, and soon they began informal contests. Being quick and accurate with a lasso aren't the only requirements in calf roping. A successful roper also must be an experienced horseman and a fast sprinter. After giving the calf a predestinated head start, the horse and rider give chase. As the cowboy throws his loop, the horse comes to a stop. After catching the calf, the cowboy dismounts, runs to the calf, throws it to the ground by hand (called "flanking") and ties any three legs together using a "pigging sting" he has carried in his teeth throughout the run. While the contestant is accomplishing all this, the horse must keep the slack out of the rope, but not pull it tight enough to drag the calf. If the calf is not standing when the roper reaches it, the cowboy must allow the calf to stand before making the tie. When the roper has completed this tie, he throws his hands in the air as a signal to the flag judge. He then remounts his horse and rides toward the calf, making the rope slack.