It is not straightforward to do a direct efficiency comparison between MD and MD/NCMC simulations since we incur additional computational costs during the NCMC alchemical steps, which are not counted towards the final trajectory length. Force evaluations are the most expensive calculation in simulations and we are interested in sampling more transitions between different binding states. Hence, we compared the two methods based on the observed number of transitions per million force evaluations (transitions/million f-ev).