Distribution of the six CC criteria that we considered for all 352 halos of TNG-Cluster at z = 0. From upper left to lower right, these are: central cooling time, central entropy, central electron number density, cuspiness parameter, physical X-ray concentration, scaled X-ray concentration. In each case, the SCC (NCC) thresholds are indicated by the dotted (dashed) vertical lines. Each of the 20 bins is colored by the mean M_500c of all clusters in the bin. The left-most (gray) bin in the histogram of the cuspiness parameter indicates all clusters that have α < 0. The histograms indicated by the black lines are the results from Andrade-Santos et al. (2017), Hudson et al. (2010) (see text for details). The comparison is only meant to be qualitative, as we did not replicate the measurement procedure of the observational data. In all six cases, TNG-Cluster produces continuous distributions of CC criteria with no clear bimodalities. The thresholds from previous works and observational findings do not clearly coincide with any features in our distributions.