Correlations between physical parameters and magnitude at different epochs. Top panels: correlations between M_bol, end and two physical parameters: E (top left) and M_Ni (top right). Bottom panels: correlations between M_bol, tail and two physical parameters: E (bottom left) and M_Ni (bottom right). The yellow and red markers refer to the results obtained from the CSP-I SN II sample (yellow markers indicate gold events). Each subplot contains the number of events (N), the Pearson correlation coefficient (ρ), and the probability of detecting a correlation by chance (P) for the full sample. Results from the models are colour-coded based on different physical parameters. The physical parameters not being varied –if they do not appear in the plot– are fixed at M_ZAMS = 10 M_⊙, M_Ni = 0.03 M_⊙, and ⁵⁶Ni mixing = 0.5. Some observations fall outside the range of the model parameters because of the fixed physical parameters. Changes in the fixed values represent different ranges of model parameters.