The average properties of the z = 12 collapsing regions from which z = 0 halos originate. Left: Average properties of the regions in which older (low a_1/2) and younger (high a_1/2) halos form. Right: Same but for virial concentration (low and high c_vir). From top to bottom, the mean values of the sphericity, ellipticity, concentration, triaxiality, velocity dispersion, and radial velocity of the corresponding clouds are presented for each subset separately. Errors were estimated using a bootstrap procedure based on 1000 resampling subsets.