Figure 1.

Probability that a PNE is not PPO in two-player ordinal finite random games where each player has m actions. Solid line, probability computed by numerical quadrature of Eq. 2; ×, fraction estimated from 2,500 simulations for each m; dotted and dash–dotted lines, lower and upper limits of 99% confidence intervals (±2.57 standard deviations) around ×.