Grand Challenge 4 Evaluation Results

This section presents metrics of the ability of the predictions to correctly rank ligands by affinity. The rankings were evaluated in terms of the Kendall's τ and Spearman's ρ. Predicted binding energies for the free energy sets were additionally evaluated in terms of centered root-mean-square error (RMSEc, kcal/mol) [1] and Pearson's R. Uncertainties in these statistics (e.g., Kendall's τ Errors in the table) were obtained by recomputing them in 10,000 rounds of resampling with replacement, where, in each sample, the experimental IC50 or Kd data were randomly modified based on the experimental uncertainties. Experimental uncertainties are added to the free energy, ΔG, as a random offset δG drawn from a Gaussian distribution of mean zero and standard deviation RTln(Ierr). In this evaluation, the value of Ierr was set to 2.5.