Correlations between physical and observed parameters using the results from non-standard pre-SN models. Left panel: M_Ni versus pd. Right panel: M_Ni versus optd. Each subplot contains the number of events (N), the Pearson correlation coefficient (ρ), and the probability of detecting a correlation by chance (P). Blue triangles show the results obtained using non-standard pre-SN models, while green squares indicate results from standard evolution. SNe labelled as ‘non-standard’ have Bayes factors greater than 10^1/2.