In an attempt to evaluate a wider range of microscopic pK a s, we compared our predictions with some of the top results from the macroscopic analysis. SimulationsPlus' pK a Predictor (submission ID hdiyq) and ACD Lab's pK a GALAS [49] (submission ID 8qph) both performed better than our approach in the macroscopic pK a challenge compared to experiment and provided type I predictions . We will refer to these two submissions as S+ and ACD respectively. The SAMPL6 challenge instructions encouraged all participants to submit whatever microscopic pK a s their method identified. Each method we are considering for comparison here reported a different number of microscopic pK a s. Using our algorithm, we calculated 254 microscopic pK a s while, S+ reported 313 and ACD reported 65. In Figure 5, we compare our results with these two products (Figure a and b), then we also compare S+ and ACD predictions with each other (Figure ). For all three comparisons, all microscopic transitions predicted by both methods are considered. The two commercial predictions agree reasonably well with one another (RMSE of 1.9±0.2). Thus, comparing our predictions to both allowed for a more informative analysis of our microscopic pK a predictions than comparing them to macroscopic experimental data. Our results initially seem less promising than the analysis for SM07 and SM14 discussed above with an RMSD of 4.7 ± 0.2 compared to S+ (5a) and 2.9 ± 0.2 compared to ACD (Figure ). Our model is trained on a limited data set, evident in that it has a smaller dynamic range than either reference method. Therefore, large errors on predictions involving highly charged microstates are to be expected.