Properties of the overdensities detected among the mock galaxies with i_sel ≤ 27.5 at 2 <  z <  3 (red) and 3 <  z <  4 (blue). The properties of the fiducial run overdensities (2 <  z <  3FID and 3 <  z <  4FID) are shown as dots and the properties of the overdensities detected after including z_phot errors (mimicking the VANDELS data) and adopting THRESHOLD = 6 (2 <  z <  3TH6 and 3 <  z <  4TH6) are shown as stars. The leftpanels show the total number of members versus the mean distance between the members and the highest-density peak, the rightpanels show the maximum distance between the members and the highest-density peak and the standard deviation of the observed redshifts in velocity [c × stdev(z_obs)]/[1 + mean(z_obs)]. The fiducial-run overdensities missed after applying photometric uncertainties are indicated with black circles around the dots (missed). The ‘fake’ overdensities at z ∼ 3 (3 <  z <  4TH6fake), not detected in the fiducial run, are shown as squares. To read this figure, we remind that each star (recovered overdensity) corresponds to a dot (fiducial-run overdensity) without black circle. The overdensities detected among the mock galaxies with i_sel ≤ 26.1 share the same properties of the ones detected among the mock galaxies with i_sel ≤ 27.5.