Heuristic Sensing: An Uncertainty Exploration Method in Imperfect Information Games
An example of the information set in RBC game. The root node is a white turn node. After the white player moves, the black player faces many indistinguishable possible states that are created by the opponent’s unknown move; e.g., (a2, a3) and (b2, b3, are all possible move actions. These indistinguishable states in the dotted box form an information set of the black player.