We are not concerned with which strategy won against any particular opponent. What matters is which strategy accumulated the most ‘money’, summed over all its 15 pairings. ‘Money’ means simply ‘points’, awarded according to the following scheme: mutual Cooperation, 3 points; Temptation to defect, 5 points; Punishment for mutual defection, I point (equivalent to a light fine in our earlier game); Sucker’s payoff, o points (equivalent to a heavy fine in our earlier game).
