Abner Doble considered Stephenson valve gear: ""(...) the most universally suitable valve gear of all, for it can be worked out for a long engine structure or a short one. It can be a very simple valve gear and still be very accurate, but its great advantage is that its accuracy is self-contained, for the exact relationship between its points of support (eccentrics on shaft, valve crosshead, and link hanger arm) have but little effect on the motion of the valve. Its use on engines in which all the cylinders lie in one plane, represents, in the belief of the writer, the best choice."" Another benefit of the Stephenson gear, intrinsic to the system, is variable lead: usually zero in full gear and increasing as cutoff is shortened. One consequent disadvantage of the Stephenson gear is that it has a tendency to over-compression at the end of the stroke when very short cut-offs are used, and therefore the minimum cut-off cannot be as low as on a locomotive with Walschaerts gear. Longer eccentric rods and a shorter link reduce this effect.