Evolutionary tracks of the produced sdBs and the sdB samples with atmospheric He abundance (Németh et al. 2012) on the effective temperature-gravity diagram. The shaded area between the lowest two lines is the region of the evolutionary tracks that are occupied by the flash-mixing models. The age difference between adjacent crosses on the evolutionary tracks is 10⁷ yr. The cross stands for CPD-20^o1123, an intermediate He-rich sdB with an orbital period of 2.3698 d (Naslim et al. 2012). The grey lines are the tracks during helium flashes before stable He-core burning.