Originally Posted by
FBinNY
Yes, there's maybe some ability to manage the fall, but very little. As I noted these happen very quickly. However inertia works in your favor. There's not much torque applied to your body, so you don't get the 90° rotation that would have you hitting shoulder first. IME (fairly extensive with ice and black ice) these falls usually have you landing hip or thigh first, and the natural action tends to give you the necessary rotation to the back of the shoulder whether you try or not....
All of my slips have been from some turning maneuver, and the point of the shoulder is on an arc direct to ground. I wouldn't say "very little" ability to manage the fall, because if you're quick enough to do the technique you'll be OK, every time, excluding some extraneous factor. Circling the arm out to slap will torque your body, which is one reason why you should always try to do that even if you mis-time it. Just falling free without reacting, I hit on the shoulder point, every time, the last time resulting in a break. You're probably positioning yourself during the fall without consciously realizing it.