During flatwork, a useful upper-level movement is the half-pass. It receives its name from being a half-forward and half-sideways movement--that is, the horse travels on a diagonal line that is at a 45-degree angle from the long side of the arena. The combination of the forward track and sideways track is the reason this movement is also commonly referred to as the "two track."
The half-pass can be performed at the walk, trot, or canter, although it would be unusual to incorporate it at the canter into the schooling routine of an equitation horse or jumper. When moving counterclockwise, in order to perform the half-pass across the diagonal, your aids are as follows:
The left indirect rein creates a slight bend in the horse's neck. The left leg at the girth drives the horse forward during the half-pass; and the right leg in a behind-the-girth position initiates and sustains the lateral motion. To begin the half-pass, move both hands to the left to bring the horse's inside shoulder slightly off the track, just as in the shoulder-in. Then, when you immediately apply your right leg to begin the lateral movement, the horse's shoulders will be correctly preceding the haunches. The animal's body should be almost parallel to the long sides of the arena during the movement, with the forehand preceding the rest of the body only slightly.
The horse's right foreleg crosses in front of its left foreleg, and its right hind leg crosses in front of its left hind leg. Since it is difficult for most riders to position the horse properly and initiate the crossing of the legs when they first try this movement, it is best to begin at the walk, rather than at a faster gait, so that you have time to think about what you are doing and correct your errors.
Once you can perform the movement at the walk, try it at the sitting trot, encouraging your horse not only to cross the outside legs over the inside ones, but also to have a swinging, athletic motion during the crosses. By concentrating on an imaginary line from your left seat bone to a point at the end of the diagonal line on the other side of the arena, you will naturally shift your aids to move the horse laterally. You may, however, have trouble maintaining the slight bend in the neck and keeping the horse's shoulders in front of its haunches, since these are typical problems during the half-pass. If the horse starts to invert its bend or catch up to its shoulders with its haunches, use a left opening rein to correct these errors. As always, if impulsion drops radically during the movement, straighten the animal and drive it forward until the desired impulsion is regained, then attempt the movement again.
Although the half-pass can be beneficial in training a horse, it is a difficult movement that is performed badly by many riders and, for this reason, may hinder more than help a horse. Teaching the movement to an equitation rider is more for the sake of rounding out his education than necessary for improving his horse, since there are other, easier movements that can teach the horse the basic concept of moving toward the bend, such as the advanced turn on the forehand, turn on the haunches, or travers.
If you believe the difficulty of the half-pass outweighs its benefits, do not hesitate to discard it from your schooling routine, since it is not included in any equitation tests and therefore is not mandatory for a hunter seat equitation rider to perform. However, if you find it useful in training your equitation horse or jumper, then incorporate the movement into your work.