The cowgirl’s time begins when she crosses the starting line in the arena, where she may run to either the right or left barrel first. Time ends when the contestant has completed the cloverleaf pattern and raced back across the finish line. If she knocks a barrel down, a five-second penalty is added to her time. She is disqualified for running off course.

Top barrel horses are usually Quarter Horses, bred for athletic ability, agility, quickness and speed at short distances. Some barrel racers prefer a Quarter Horse with some Thoroughbred breeding mixed in for extra speed and a more explosive disposition. Still others can be seen "chasing the cans" on Paints, Appaloosas or non-registered horses. Whatever the breeding, barrel horses are highly trained. Only the best horses can turn in winning times consistently. This equine athlete must run full speed, check himself and make a 360-degree turn around a barrel, then run hard again to the next barrel. Barrel racing requires extreme precision, as winners are often decided by a mere thousandths-of-a-second.