D strategists may temporarily invade a population of C strategists by scoring equally well against C, but they pay a price when they begin to play against each other; C scores better against D than does D. So here although E(C, C) = E(D, C), it is also the case that E(C,D) > E(D,D).
Strategi D bisa secara sementara menginvasi populasi C dengan memberikan nilai yang sama melawan C, tetapi mereka membayar harganya saat bermain dengan satu sama lain; C memiliki nilai lebih baik melawan D daripada D. Jadi walaupun E(C,C) = E(D,C), juga E(C,D) > E(D,D).