Expanding the set to the top 50 catalysts, the structure only classification method was able to find eight sites, whereas the classification method trained on all features found 43. The speedup ratio for the sequenced classification/regression approach trained with all features and applied to the top 15 sites in this scenario is quite similar to the results from scenario two (Figure ). The results in Figure show relatively similar performance for both methods relative to random up until the sixth site, at which point the structure feature trained method drops significantly in relative performance. This drop occurs because while the structure feature trained classifier predicted these sites are active, the regressor does not correctly predict all these sites will be very active. The regressor trained on all features has a similar behavior which is not visible here because the classifier trained on all features identified 43 active sites, so the drop in performance would be visible only if the total number of sites in the goal approached 43.