Axelrod's Tournamentwas played in the 80s, and initially he solicited strategies from other game theorists to compete in the tournament. Each strategy was paired with each other strategy for 200 iterations of an Iterated Prisoner's Dilemma game, and scored on the total points accumulated through the tournament. Even there were many complex strategies; the winner was the simplest deterministic strategy, of all the competing programs. It was submitted by Anatol Rapoport, and known as “TIT FOR TAT” (TFT) that “cooperates on the first move, and subsequently echoes (reciprocates) what the other player did on the previous move”. The results of the first tournament were analyzed and published, and a second tournament held to see if anyone could find a better strategy, but TFT won again. Axelrod analyzed the results, and
made some interesting discoveries about the nature of cooperation in these scenarios, which he describes in his book (Axelrod, 1984).