I guess nothing can calculate exactly all the variables David, but Larry is right, it did give a good analysis of how the rode works, as a separate issue from the anchor performance itself. I was also interested to see it supported Eric's belief that a mixed rode, ie chain to the anchor, and rope (preferably nylon), to the boat was the best in the extreme. The evidence being that one tries to use longest & heaviest reasonable length of chain, and then the length of rope rode becomes fairly flexible, from almost nothing in the light, to "let her all out" in a blow. That's how I read it anyway. I guess what was implied was that it was also sensible to have the best performing anchor possible locating the end, though that particular debate was not covered. Good stuff.