Outcome of the first mass transfer phase in our detailed binary evolution models with an initial primary mass of 17.8 M_⊙. In this figure, each pixel represents one detailed MESA binary evolution model, and the corresponding evolutionary outcome is colour-coded (see top legend). Here, ‘OB+cc’ (cc= BH, NS, WD) implies that the corresponding model produced an OB+cc phase, with the cc type indicated by the corresponding colour. However, depending on the adopted compact object birth kicks, these systems may also break up. Systems indicated as ‘Upper_mdot_limit’ or ‘MT_max’ are terminated during their first mass transfer phase as the mass transfer rate exceeds limiting values (see text) and a merger is expected, and those indicated as ‘other merger’ undergo L2-overflow in a contact situation. Corresponding plots for different initial donor star masses can be found in Appendix A.