From personal experience, I can say it works perfectly, if you're skilled enough for it to become a 2nd nature.
I trained judo as a small child, mostly learning falls and cushioning them. I've been using that ever since in countless number of situations - football, cycling, motorcycling. I do those things instinctively. Never hit my head in any fall so far. That includes being hit by a car 4 times (so far ).

Just like most boxers move their head and reposition themselves after deploying a hit, regardless of whether the opponent tries to hit them back, or not.