Good points. Simulations do give much less information than visible source code--this was a deliberate design choice on my part, but you are probably right that this kind of setup is not really "program equilibrium." I admit, I don't have a very good understanding of where the limits of the PD game really are, and I hadn't considered the problem of the all-players tie (fortunately I don't think it is going to happen in practice). Mutual cooperation and cliques are still viable strategies here, but they may not be the Nash equilibrium anymore. Regardless, I agree that this tournament is horribly misnamed.