translation.en: He started a computer tournament for people to submit prisoner's dilemma strategies and discovered, much to his surprise, that a very, very simple strategy won -- it won the first tournament, and even after everyone knew it won, it won the second tournament -- that's known as tit for tat.
translation.zh: 阿克塞罗德开始了一个电脑竞赛 让人们针对囚犯困境，提交各自策略， 然后他意外的发现，其中最最简单的策略竟然赢了。 这个策略赢了第一场比赛，甚至在大家都知道这件事之后， 还赢了第二场竞赛。这个策略就是以牙还牙。