Then, with respect to \(B\)’s appropriately updated knowledge about \(A\)’s choice at \(v_3\) (according to his specified belief revision policy), his strategy \(O_2\) is in fact rational. According to Stalnaker, the rationality of a choice at a node \(v\) should be evaluated in the (counterfactual) epistemic state the player would be in if that node was reached. Assuming \(A\) knows that \(B\) is using the belief revision policy described above, then \(A\) knows that \(B\) is substantively rational in Stalnaker’s sense. If the model includes explicit information about the players’ belief revision policy, then there can be common knowledge of substantive rationality (in Stalnaker’s sense) yet the players’ choices do not conform to the backward induction profile.