King walks in the middlegame are already unusual when they are taken voluntarily and don't lead to mate; when they involve the white king going all the way to h8, and when this is done as a matter of home preparation? That must be unique or at most very nearly so. That's what David Navara pulled off today in his victory over Radoslaw Wojtaszek in round 4 in Biel. Wojtaszek, to his credit, played extremely well for a long time, and by contrast Navara made a couple of slips once he was out of his preparation. In the end though, Navara was able to turn his brilliant concept into a full point, and leads the event with 3/4.