$K^{2}$/$R^{2}$ Values — Rolling Race Order 0 0.2 0.4 0.6 0.8 1.0 Solid Sphere 2/5 Disc (Cylinder) 1/2 Hollow Sphere 2/3 Ring (Cylinder) 1 1st 2nd 3rd 4th

Reading this diagram: Shorter bar = smaller $K^2/R^2$ = larger acceleration = wins rolling race. The solid sphere (terracotta, shortest bar, 1st) beats the ring (dark, tallest bar, 4th).