Abstract: An improved dipper stick, tool, and thumb combination includes a progressive linkage for connecting the thumb to a thumb actuator wherein the pivot axis of the thumb idler link connection is spaced from the pivot axis of the tool idler link connection. The pivot axis of the thumb idler link connection may be offset outwardly from the inner surface of the dipper stick. A mounting plate may be connected to the inner surface of the dipper stick to locate the pivot axis in the offset position.