Eccentricity during Jacobi captures. Left panel: histogram in percent of the mean eccentricity of the binary during captures (initial captures in red and dynamical captures in blue). The dark blue line represents only dynamical captures with a single close encounter (i.e., flybys). Right panel: percentage histogram of standard deviation of eccentricity during captures. This figure is analogous to Fig. A.1 with a different capture criterion. BHs are considered bound if their relative distance falls below the binary’s Hill radius. Note that the alternative criterion adds captures for which the mean eccentricity is greater than 1.