European-style Japanese knives seem to be described (also here and here, and in my most recent post) in terms of "ratios" that always add up to 100. It's not exactly clear what this means in terms of angles off the center plane of the blade.
It appears that, even on knife forums, there is some confusion as to what these numbers mean. My first thought was that they were actually angles, since a 30 degree angle is common on European knives. Upon reflection, though, that can't be--when you're sharpening a 70/30 knife, dragging across a stone at a 70 degree would be a catastrophe. What, then, is that magic number, and how does it vary in relation to these "ratios"?