It tells Versaworks what offset you have on your blade. If you are getting new blades that are the correct ones then there will be no offset. If you are getting them resharpened then you will have an offset because the center of gravity will have changed and how the cut head drags the blade will be different. The blade works like the front wheels on a grocery cart. The shaft is offset from where the blade actually makes contact with the material. Hope that helps.