Fraction of SCC (blue), WCC (purple), and NCC (orange) clusters in the TNG-Cluster simulation as a function of redshift. We separated clusters into low-mass (dashed lines), intermediate-mass (dotted lines), and high-mass bins (solid lines). The log₁₀(M/M_500c) thresholds for each mass bin are stated in the legend. We overplot the results for the SCC fraction from observations (McDonald et al. 2013; Ruppin et al. 2021) in five of the six panels. For 0 < z ≤ 0.7, the observations should be compared to the high-mass bin (solid line) and at z ∼ 1 to the intermediate-mass bin (dotted line). The comparisons are meant to be qualitative (i.e., at face value only). The six panels show the classification based on our six fiducial CC criteria, from top left to bottom right: cooling time, entropy, density, cuspiness, and the two X-ray concentration measures. Overall, the fraction of SCC clusters is higher at earlier times, and NCC clusters appear only at z ≲ 0.5, although redshift trends depend on the adopted CC criterion.