With evidence that catalysts 3g, 3h, and 3k proceed via alternative modes of action, we hypothesized a more robust statistical model could be constructed that better describes the primary mode of enantioinduction if these three catalysts were removed from the dataset. It is probable that removing catalysts that are slower and have a more competitive uncatalyzed rate can serve to reduce the noise in the selectivity data modeled (i.e., observed selectivity would be more indicative of innate catalyst selectivity). The best four-parameter model consisted of one catalyst term and three substrate terms (Figure ). The model is substrate-dominated, with a notable catalyst term (average Sterimol L, teal, Figure ) that reads out substitution of both the phosphinate and quinoline C6′-position. The substrate molar volume (gray, Figure ) remains a model parameter, in addition to the Sterimol B1 value (purple, Figure ) and buried volume within a 2.5 Å radius of the α-carbon (green, Figure ). The sulfonimidamide substrate parameters serve to describe the nature of the substrate in the catalyst pocket, for which the substrate must provide enough steric bulk to secure its conformation for enantioinduction. Although all the statistical measures of this model improve compared to the model trained on the full dataset (Figure ), of significance, is the increased precision (~0.1 kcal/mol) of the model in leaveone-substrate-out (MAE = 0.125 kcal/mol) and leave-one-catalyst-out (MAE = 0.132 kcal/mol) analysis.