Horse Training 101
by Ray La Foy
Each horse is different in how it learns and how it reacts to outside stimuli. Certain methods of horse training may apply to some horses, but it does not mean that it will be effective to all breeds of horse.
To start horse training you must develop a communication system with the horse. This might take time. In the same way as children may not fully grasp the idea of things at an instant, baby horses in training may not get every pressure, pat or way of holding the reins at once.

tom tate
good information on young horses. i use the clicker but only on less submissive breeds.