I'd like to add one more suggestion for the next version of this tournament:

1. If you have N bots, don't run NxN matches; instead, engineer their exchanges to be less complete, and more random. This may encourage the emergence of reputation.

And more generally, I would like to see systematic explorations in post-IPD tournaments; tournaments in which bots are able to (in constrained conditions) mold the utility landscape for their own ends.