The Doyle Log Rule, developed around 1825, is based on a mathematical formula and is widely used throughout the Eastern, Midwestern and Southern United States. This rule allows for a saw kerf of 5/16 inch and a slabbing allowance of 4 inches, which is about twice the normal amount. Because of this, the Doyle Rule is somewhat inconsistent; it underestimates small logs and overestimates large logs.