That makes sense in terms of bit flipping, but does it make sense in terms of distance?<p>Assuming your mouth is a unit square, where you have to hit the four "corners", with no distance between inside and outside, with Knuth's pattern, I have to travel 5 units.<p>Meanwhile, doing inside/outside clockwise only requires 4 units.<p>Am I missing a joke or something? Why, for instance, would you go across your mouth twice just to clean your upper teeth?