Early on, every Pony Clubber and most foxhunters are taught an emergency braking maneuver called a pulley rein. Even if you have no intention of ever setting hoof on a cross country course, it’s a valuable technique to have in your arsenal. Even a normally well mannered schoolmaster can decide for reasons known only to himself to one day detour at speed down the median of your local interstate. Or more likely, attempt a dash back towards the barn. When that’s happening contrary to your plans, you’d better have recourse!

So, remember that chapter in your seventh grade science book on “simple machines”? Those are devices like a lever or an inclined plane that trade a benefit of amplified force output in exchange for an increased displacement of the force you input. You move the handle end of a crowbar a much greater distance than you lift the rock at its business end, but the weight of the rock you’re lifting can be much greater than the strength you would need to raise it unassisted.

A pulley rein is not a pretty thing, but hey, don’t forget—you’re being run away with! First you take one rein very short and you brace it firmly against the mane. Its job is to keep the horse straight. Then, while driving your knees and back deep into the horse, you lift your opposite hand with a sharp, violent pull that puts all the strength of your upper body behind it. One hand anchors; the other yanks hard—in backyard terms, the so called “anchor yanker.” In most cases, the result is a poll high, croup low, skidding stop, and the rider begins to breathe again.

Not coincidentally, half halts—though greatly refined—are administered in much the same way. They are applied diagonally as in “inside leg to outside rein” or unilaterally—leg to hand on the same side—but almost never bilaterally: both legs against both hands. The latter is only a recipe to invite your horse to hang or pull in response.

Of course, the active hand doesn’t really pull. It makes an  interrupting, momentary non-allowance in answer to the pushing aid. And the opposite hand (the would-be anchor) doesn’t brace on anything. From your elbow it merely fixes itself in space to counter the actively resisting hand, thereby governing the horse’s head and neck alignment. In that sense, you can imagine that you’re always riding with just one rein. It’s made of two leather parts and a connecting metal middle element. The point is: every action of a single rein has ramifications all the way through the horse’s mouth and back to the opposite hand. The action of the two hands must complement, and not contradict, each other.