(a) Monte Carlo simulations of 10 000 different disks (with α = 10⁻¹) and stars with stellar rotations periods drawn from a probability density distribution derived from Irwin et al. (2008) in Fig. 3. A tidal migration barrier existed in 3% of all simulations and their locations are shown in the black histogram at the top of the panel. The location of the magnetic cavity r_mc was different in each simulation, depending on the stellar rotation period. (b) Histograms of the radial distance of the magnetic cavity (r_mc), which existed in 90% of all simulations, and of the tidal migration barrier (r_tmb). The corotation radius distribution is plotted at 1/0.63 times r_mc.