The entries of the matrix specify the payoff for the row player. There are four possibilities: (i) if a > c and b > d, then strategy A dominates strategy B; (ii) if a > c and b < d, then both A and B are evolutionarily stable strategies (ESS); the game is bi-stable and is called a ‘coordination game’; (iii) if a < c and b > d, then both strategies are best replies to each other, and we have a Hawk-Dove game, where both strategies coexist; (iv) if a < c and b < d, then B dominates A.