Many riders compete without having consulted the USEF Rule Book about the judging criteria for each kind of class. Since judges constantly refer to these rules, it is important for competitors to also be aware of them. Below is a summary of some of the important guidelines on equitation classes:
Position In Motion: At the walk, sitting trot, and canter, body should be a couple of degrees in front of the vertical; posting trot, inclined forward; galloping and jumping, same inclination as the posting trot. (Note: This description clearly specifies that in equitation classes on the flat, the rider should be in three-point position at the canter, not leaning forward and raised out of the saddle in two-point position.)
Hands: Hands should be over (that is, above) and in front of the horse’s withers, knuckles thirty degrees inside the vertical, hands slightly apart and making a straight line from horse’s mouth to rider’s elbow. Bight of reins may fall on either side. (Note: Traditionally, the bight has been on the off-side of the horse for safety reasons when mounting.)
Basic Position: The eyes should be up and the shoulders back. Toes should be at an angle best suited to rider’s conformation: ankles flexed in, heels down, calf of leg in contact with horse and slightly behind girth. Iron should be on the ball of the foot and must not be tied to the girth.
General: Rider should have a workmanlike appearance, seat and hands light and supple, conveying the impression of complete control should any emergency arise.
A copy of the USEF Rule Book can be obtained from the following source:
United States Equestrian Federation
4047 Iron Works Parkway
Lexington, KY 40511
Phone: 859-258-2472
http://www.usef.org

The rider is properly sitting the canter and demonstrates a beautiful straight line between her elbow and the horse’s bit, as well as her leg being positioned so that a straight line is formed from her knee to the toe of her boot. Notice the downward stretch of her Achilles tendon, the mark of a secure rider.