The commercial product “Pipeline Pilot” uses a Naive Bayes statistics based approach, which essentially contrasts the active samples of a target with the whole (background) compound database. It does not explicitly consider the samples labelled as incative. Laplacian-adjusted probability estimates for the features lead to individual feature weights which are finally summed up to give the prediction. We re-implemented the “Pipeline Pilot” Naive Bayes statistics in order to use it on a multi-core supercomputer, which allowed us to compare this method on our benchmark dataset. … Pipeline Pilot Bayesian Classifiers (PNPBC)