Sharpening a blade from tip to center is a waste of your time and grinding wheel. Only the outer 1 inch or so, according to magna-matic, actually cuts. I still sharpen about 3 in., even on excaliber blades. Exmarks development of a blade sharpened to the center shows our ignorance. If you have a different understanding, pleas respond. Mabye someone who has done the speed of the blade at different intervals in could explain the physics.