A random baseline was computed according to the actives/inactives ratio of the training set for each strategy and each fold. Let f be the fraction of actives in the training samples involving a protein, and n the number of samples to be predicted in the test set for that protein. The random baseline is obtained by first sampling f n + 0.5 values from a uniform distribution in [0.5, 1] (actives) and n-f n+0.5 values from a uniform distribution in [0, 0.5] (inactives), then concatenating both and shuffling. This procedure keeps the active/inactive balance by design while producing random activity predictions.