Horse Trials, also known as "Eventing," are competitions held in three phases. The same horse and rider ride tests in dressage (a precision ride in a flat arena), show jumping (a round over eight or ten fences with rails that knock down), and finally a ride cross-country for one to two miles, while jumping over fences that don't knock down.

Originally, the sport was a contest between cavalry riders to test the horse and rider's ability, stamina, and training for combat. Now, civilians do it for fun.

Riders and horses compete with each other at a skill level where they are comfortable. The lowest fences and the least demanding dressage tests are at the beginner novice level, intended for those competitors who are just starting out. More difficult tests are offered at the novice, training, preliminary, intermediate, and advanced levels.

The intermediate level is the highest degree of competition offered at Greenwood Farm, but international events such as the Olympic Games are at the "advanced" level. You may recall the World Games in Spain this past summer of 2002, when the United States team won the gold medal. Greenwood Farm's course designer, John Williams of Virginia, scored the highest individual score of all competitors on the cross-country phase.

A horse may only compete at one level at any event, but many serious amateurs and professionals have several horses competing at different levels. They count the scores in penalties, a measure of things that you did wrong instead of what you did right. In dressage, a judge grades every move and subtracts the total score from the grade for a perfect ride. In show jumping, a rail knocked down is five more penalties. If the horse refuses to jump over the fence the first time, he gets 10 penalties for the first refusal, 20 points for the second one, and he is shown the out gate after three refusals. On cross-country, those show jumping penalties double, except that the rails won't knock down.

Finally, the horse and rider must perform the jumping tests against a clock, not to be the fastest, but to be closest to what is determined to be the optimum time. When all is done, the penalties are added up and the low score wins - sort of like golf.