Distribution of the initial conditions of the binaries that reproduce the Gaia BH3 properties after BH formation. From top left to bottom right, the panels show the initial binary period, initial eccentricity, the module of the BH natal kick velocity, and the initial mass of the BH progenitor. We show the distributions obtained assuming different Maxwellian-distribution priors for the kick velocity: σ_v = 1 km/s (blue thick solid line), σ_v = 10 km/s (orange thick dashed line), σ_v = 50 km/s (green dotted line), σ_v = 100 km/s (red thin solid line), σ_v = 256 km/s (violet thin dashed line).