Like many sports, the world of Thoroughbred racing has a lot of statistics that most people can look up. Some of the information is very useful and some of it is overkill.
When many handicappers, and even novice fans, look at a racing program or the past performances in other publications, their eyes are drawn to a slew of numbers associated with each horse. At the bottom of each entrant is a list of pre-race "workouts" the horse has done, usually once a week in the mornings.
Workouts are simply when a horse runs as fast as he or she will in a regular race, and occur as part of a normal training regimen to keep the equine in top form. The workouts are timed by each individual race track/training center, each of which has an official "clocker," and then that information is attached to the horse's permanent statistical record.
Those workout times are usually utilized by the savvier handicapper to determine how ready the horse may be for his or her next start, and they are especially invaluable when the horse is early in its racing career or coming back from an extended vacation.
The official timekeepers, however, are not the only ones who watch and time every workout. There are a group of private clockers, scattered throughout the country, who do much the same the thing but have a more vested interest in every bit of the horse's morning workout.