“From the participant’s point of view, the object is to do as well as possible, regardless of how well the other player does. Based upon the tournament results and the formal propositions, four simple suggestions are offered for individual choice: do not be envious of the other player’s success; do not be the first to defect; reciprocate both cooperation and defection; and do not be too clever.”

这是一个非常精炼的总结。每个人的目标是是想要做到自己能做到的最好，而不是觉得自己做的比别人差就是失败。从竞标赛结果来看，要实现这个目标，有四个方面值得考虑（书后面会具体聊）：不要季度其他玩家的成功，不要先背叛，要以牙还牙以眼还眼，不要太自作聪明（觉得自己可以投机取巧占别人小便宜）

“Would the results of the second round have been much different if the distribution of entries had been substantially different? Put another way, does TIT FOR TAT do well in a wide variety of environments? That is to say, is it robust? A good way to examine this question is to construct a series of hypothetical tournaments, each with a very different distribution of the types of rules participating. The method of constructing these drastically modified tournaments is explained in appendix A. The results were that TIT FOR TAT won five of the six major variants of the tournament, and came in second in the sixth. This is a strong test of how robust the success of TIT FOR TAT really is.”

令我感到惊讶的是，一个很简单的策略赢了两轮竞标赛，参与者都是相关行业的大师。赢的策略叫做TIT FOR TAT：第一次遇到任何玩家都选择合作，下一次遇到同个玩家就执行这个玩家上次的动作，比如上次是背叛，那我这次就背叛，上次是合作，这次就合作。这个策略的成功并不是偶然，主办方还做了6次模拟，每次模拟选取了不同策略分布（比如有一些竞标赛，不合作的策略多，有一些合作的策略多），6次竞标赛中TIT FOR TAT 5次冠军1次亚军，证明了它在不同环境中的鲁棒性。后面会有详细的分析为什么这种策略能成功，以及现实中的应用案例。