Fraction of binaries with q > 0.5 in the core as a function of some parameters of their host GCs. Clockwise: ellipticity, central concentration, central velocity dispersion, logarithm of the central luminosity density, half-mass and core relaxation timescale, and metallicity. In each panel we quoted the Pearson correlation coefficient (r). PCC clusters are marked with red crosses and are not used to calculate r (see text for details).