The calves are lined up in a row and moved through narrow runways leading to a chute with spring-loaded doors. When a calf enters the chute, a door is closed behind it and a lightweight 28-foot (8.5 m) rope, attached to a trip lever, is fastened around the calf's neck. The lever holds a taut cord or "barrier" that runs across a large pen or "box" at one side of the calf chute, where the horse and rider wait. The barrier is used to ensure that the calf gets a head start. When the roper is ready, he (or, in some roping events, she) calls for the calf, and the chute operator pulls a lever opening the chute doors and releasing the calf. The calf runs out in a straight line. When the calf reaches the end of the rope, that trips the lever, the rope falls off the calf, and the barrier for the horse is released, starting the clock and allowing horse and rider to chase the calf.
Timing is critical. From a standstill, a rider will put his horse into a gallop from the box shortly after the calf leaves the chute, so that the horse saves valuable seconds by being at near-full speed the moment the barrier releases. However, if the rider mistimes his cue to the horse and the horse breaks the barrier before it releases, a 10-second penalty will be added to his time. This is sometimes referred to as a "Cowboy Speeding Ticket."
The rider must lasso the calf from horseback by throwing a loop of the lariat around the calf's neck. Once the rope is around the calf's neck, the roper signals the horse to stop quickly while he dismounts and runs to the calf. The calf must be stopped by the rope but cannot be thrown to the ground by the rope. If the calf falls, the roper loses seconds because he must allow the calf to get back on its feet. When the roper reaches the calf, he picks it up and flips it onto its side. Once the calf is on the ground, the roper ties three of the calf's legs together with a short rope known as a "piggin' string". A half-hitch knot is used, sometimes referred to colloquially as "two wraps and a hooey" or a "wrap and a slap". The piggin' string is often carried between the roper's teeth until he uses it. The horse is trained to assist the roper by slowly backing away from the calf to maintain a steady tension on the rope.
When the tie is complete, the roper throws his hands in the air to signal "time" and stop the clock. The roper then returns to his horse, mounts, and moves the horse forward to relax the tension on the rope. The timer waits for six seconds, during which the calf must stay tied before an official time is recorded. Top professional calf ropers will rope and tie a calf in 7 seconds. The world record is just over 6 seconds.