Monte-Carlo Tree Search for Poly-Y

Monte-Carlo tree search (MCTS) is a heuristic search algorithm that has recently been very successful in the games of Go and Hex. In this paper, we describe an MCTS player for the game of Poly-Y, which is a connection game similar to Hex. Our player won the CodeCup 2014 AI programming competition. Our player uses MCTS with the all-moves-as-first heuristic, and detects basic heuristic patterns to defend virtual connections in Poly-Y. In the CodeCup, we can only use 30 s single-core computation time per game, whereas in Hex, 5 to 30 minutes of multi-core computation time is common. We improve the performance of our player in the early game with an opening book computed through self play. To assess the performance of our heuristics, we have performed a number of experiments.