Unless he figures you’re not an idiot and you already know that, in which case it’s better for him to have a rule that says “always one-box on Newcomb-like problems whenever the payoff for doing so exceeds n times the payoff for failed two-boxing” where n is a number (probably between 1.1 and 100) that represents the payment differences. Obviously, if he’s playing against something with no ability to predict his actions (e.g. a brick) he’s going to two-box no matter what. But a human with theory of mind is definitely not a brick and can predict his action with far better than random accuracy.
Unless he figures you’re not an idiot and you already know that, in which case it’s better for him to have a rule that says “always one-box on Newcomb-like problems whenever the payoff for doing so exceeds n times the payoff for failed two-boxing” where n is a number (probably between 1.1 and 100) that represents the payment differences. Obviously, if he’s playing against something with no ability to predict his actions (e.g. a brick) he’s going to two-box no matter what. But a human with theory of mind is definitely not a brick and can predict his action with far better than random accuracy.