This is somewhat analogous to equilibrium pricing of financial futures contracts ("fair price" 25 ) -another way of framing the question could be "starting from this set of compounds (in a project with assay results), how many compounds would one need to make before finding one with a ten-fold improvement in assay result?". The fair price in this case might be the median number of compounds required over repeated randomized simulations. Another avenue would be to examine the effect of different project management strategies (e.g. early stopping) for a realistic range of model parameters -this is analogous to the work described in reference 2 but with a model more directly related to real world parameters.