Fraction of isolated MSPs in GCs as a function of the threshold orbital separation a_H. Smaller values of a_H shift the hard–soft boundary to smaller orbital separations so that even relatively compact binaries fall in the soft, ionizable regime (i.e., a ≳ a_H) and are disrupted through encounters. Non-core-collapsed clusters with more than 10 detected MSPs are shown with red squares, while those with more than 5 are shown with blue squares. Lines of different colors show the three simplest models tested (see Table 3), each fitted to the non-core-collapsed clusters (red squares and blue circles); the shaded gray region marks the 1σ confidence interval of our fiducial model, ﹩A\,{a}_{{\rm{H}}}^{-0.5}﹩ (black line).