Fig. -Diene (top) and dienophile (bottom) distortion energy test set predictions for SVR models for ds2. These models were chosen because they achieved the best performance on the test set for their respective targets. The dotted line indicates perfect agreement between predicted and true values. The grey region shows the 1 kcal mol -1 threshold either side of this perfect agreement. Random seed for both is 14. kcal mol -1 respectively (Table ). The best model built on ds2 yielded an MAE of 0.41 kcal mol -1 (RS=14) which is well below the 1 kcal mol -1 accuracy threshold (Fig. ). The averaged test MAE for ds2 was 0.50 ± 0.06 kcal mol -1 (Table ). When predicting ds3 interaction energies, the best performing model was again SVR. The best model achieved a test MAE of 2.33 kcal mol -1 (RS=1) which, when considered against the pre-ML MAE of 20.01 kcal mol -1 , is a striking improvement and in line with literature predictions of this dataset's reaction barriers. When averaged over five random states, the test MAE was 2.46 ± 0.12 kcal mol -1 . Another approach to evaluating model performance is to consider the test MAE as a percentage of the range of test values. Table shows the averaged test set performances for SVR models for each distortion and interaction energy over five random states. Evaluating ds3 performance solely on MAE would lead to the conclusion that the models are above the 1 kcal mol -1 accuracy threshold and thus not as accurate as other models, however, when considering the MAE as a percentage of the test set range, the performance is comparable to that of the Michael addition models (ds1 and ds4).