Computing an approximate jam/fold equilibrium for 3-player no-limit Texas Hold'em tournaments

A recent paper computes near-optimal strategies for twoplayer no-limit Texas hold’em tournaments; however, the techniques used are unable to compute equilibrium strategies for tournaments with more than two players. Motivated by the widespread popularity of multiplayer tournaments and the observation that jam/fold strategies are nearoptimal in the two player case, we develop an algorithm that computes approximate jam/fold equilibrium strategies in tournaments with three — and potentially even more — players. Our algorithm combines an extension of fictitious play to imperfect information games, an algorithm similar to value iteration for solving stochastic games, and a heuristic from the poker community known as the Independent Chip Model which we use as an initialization. Several ways of exploiting suit symmetries and the use of custom indexing schemes made the approach computationally feasible. Aside from the initialization and the restriction to jam/fold strategies, our high level algorithm makes no poker-specific assumptions and thus also applies to other multiplayer stochastic games of imperfect information.