Critical mass ratios (q_crit, where q ≡ M_a/M_d) for all our binary models as interpolated contours. The three panels show critical mass ratios derived using different criteria (outlined in Sect. 3), as indicated at the top of each panel. The colour shows the value of the critical mass ratio, following the colour bar at the top of the figure. The results shown in panel b are for A_dyn = 0.05. The green dashed lines show the donor radii corresponding to the end of the main sequence (TAMS), the base of the RGB (BRGB), and the tip of the RGB (TRGB), from bottom to top.