Teoria dos Jogos: Um software para simular o torneio e a estratégia OLHO por OLHO

A IOWA State University possui um ótimo sofware para simularmos os resultados do famoso torneio de Robert Axelrod, onde a estratégia OLHO POR OLHO (TIT FOR TAT).

O link é http://www.econ.iastate.edu/tesfatsi/demos/axelrod/axelrodT.htm

Com o software você pode escolher quais estratégias jogarão entre si, quais os payoffs, quantas rodadas e verificar os vencedores em formato de tabela e gráfico.

Dois grandes livros que explicam o Computer Prisioner´s Dilemma Tournament e o resultado da estratégia OLHO POR OLHO são:
- The Evolution of Cooperation, de Robert Axelrod
- Prisoner´s Dilemma, de William Poundstone

Trechos destes livros sobre o TIT FOR TAT são reveladores:

"The trouble with TIT FOR TAT. As well as TIT FOR TAT performed, it does not follow that it is the "best" of all possible strategies. It is important to realize that no strategy is good or bad out of context. How well a strategy does depends on the strategies with which it interacts. TIT FOR TAT does have several failings. It doesn´t take advantage of unresponsive strategies. When paired with ALL C (1), TIT FOR TAT coorperates and wins 3 points each dilemma.

It would do better to defect and win 5 points. In fact, with any unresponsive strategy, the best course of action is to defect. Defection always yields a higher payoff in the current dilemma, and there is no possibility of retaliation with an unresponsive strategy. TIT FOR TAT is more or less predicated on the assumption that the other player is trying to get a good score. After the first move, TIT FOR TAT repeats the strategy of the other player. When paired with a "mindless" strategy like RANDOM, TIT FOR TAT descends to its level and does no better." (Poundstone)

"TIT TAT won the tournament because it did well in its interactions with a wide variety of other strategies. On average, it did better than any other rule with the other strategies in the tournament. Yet TIT FOR TAT never once scored better in a game than the other player! In fact, it can´t. It lets the other player defect first, and it never defects more times than the other players has defected. Therefore, TIT FOR TAT achieves either the same score as the other player, or little less. TIT FOR TAT won the tournament, not by beating the other player, but by eliciting behavior from the other player which allowed both to do well. TIT FOR TAT was so consistent at eliciting mutually rewarding outcomes that it attained a higher overall score than any other strategy." (Axelrod)

A grande contribuição deste simulador é fazer estes testes. Eu fiz. E é verdade sobre os pontos acima.