Redshift evolution of the six central properties used to classify (N)CC clusters from z = 0 to z = 2. These properties are, clockwise from the upper left, cooling time, entropy, electron number density, scaled X-ray concentration, physical X-ray concentration, and cuspiness. Each panel includes two sets of violins: the left (teal) shows the distributions for the entire TNG-Cluster sample, while the right (yellow) shows only the high-mass halos with M_500c > 10¹⁵ M_⊙. In this latter case, we probe the evolution at an approximately fixed halo mass, and the number in each bin is indicated. The horizontal gray lines mark the thresholds between NCC, WCC, and SCC clusters. The strong redshift evolution is due both to the evolving mass distribution of the sample, with lower-mass clusters at earlier times, as well as the physical evolution in central gas properties.