Ratio of He to H abundance at the surface related to the solar value, [He/H], versus effective temperature, for our theoretical models and the observations. The sdB samples are from Németh et al. (2012) and have been divided into three types, i.e. H-rich, intermediate He-rich, and He-rich, as indicated in the figure. The diamonds are for the flash-mixing sdBs and the stars are for the canonical sdBs, where the He and H abundances are chosen at the onset of stable helium-core burning. The cross stands for CPD-20^o1123, an intermediate He-rich sdB with an orbital period of 2.3698 d (Naslim et al. 2012).