No, tedsanders is right. If the game has imperfect information but is zero-sum (i.e. the goals of players are perfectly opposed), you can always compute the subgame-perfect Nash equilibrium in mixed strategies, and it will be the best way to play against all possible opponents, both deterministic and random.

Mind games (bargaining, precommitment, etc.) only become important in non-zero-sum games, where the goals of players align in some ways and oppose in others. For example, if chess had an additional possible outcome where both players lose, that could make it impossible to find a single best strategy.

Thanks, that's an interesting nuance.