Predictability is not a big thing with horses, which required the development of “horse sense” in the handler. There is a connection between horse and rider that borders upon an emotional bond, as much for the horse as the rider.
Horses look at the world differently than you or I, with its eyes able to focus independently. The horse is looking at two different views of the world, the left-hand side and the right-hand side. Also, the horse has an extremely sensitive muzzle, and for the most part, a relatively sensitive mouth, which makes it possible to control even a rather unruly horse, with the proper bridle and bit.
By nature a rather timid beast, in a world filled with carnivorous creatures, the horse is the ultimate defensive player. Armed with a strong jaw filled with teeth able to inflict a very painful bite, and well-developed single-digit hooves on all four feet, the horse can inflict deadly force with any of the hooves, by either rising in the hindquarters and striking down with the forefeet, or pivoting on the forequarters and striking outward with the rear hooves. The trick is to charm the horse so you may get within range of these very potent weapons without exciting its response to you as predator, and make use of the horse’s capabilities to maintain a relatively swift pace (compared to merely human mobility), and its capability to graze off what would be very unpromising forage when crossing a hostile environment.
It is really something to be in control of a beast some ten times your weight, and standing as high at the shoulder as an average sized person, earning its trust and compliance.
Spot on. I can only add that you can tell the directions(!) a horse is looking by observing the ears, you have maybe a half of a second to react if they try to kick you (and if you are expecting the kick—as you should at all times), and never, ever forget that the kick will be delivered with pinpoint accuracy.