Heat map showing the probabilistic distribution of the absolute magnitude (M_V, max) at maximum brightness to orbital period (P) of CBs, for the LMC and SMC. O- and B-type systems are distinguished by a magnitude cutoff at M_V, max = −4. The OGLE data are annotated as in Fig. 6. For reference, the theoretical extent of the bona fide CB sample is indicated by the polygon outlined in blue dots, beyond which their number counts from de-convoluted histograms (green histograms) drop below one.