Superposition of the successive positions of the system in simulation S2 over the 2:1 ACR positions as functions of G. ACR positions are computed using our model with the parameters of the considered system (masses). The colors of ACR are consistent with graphs of Sect. 2 but we inverted continuous and dashed lines in order to improve the visibility of the simulation dots. The gray dots correspond to the migration phase and go from the right to the left of the graph whereas the black ones correspond to the tidal circularization phase and go from the left to the right.