This would ensure that no player will be in a position to know the exact move of the opponent in any play even if he knows the probabilities of mixing. These types of strategies are called mixed strategies. The mixed strategies may be (1/6, 5/6) or (1/3, 2/3) or (1/2, 1/2 ) or any other such combination with total 1. The extreme strategies (1, 0) and (0, 1) are pure strategies as they correspond to repeated plays of Head and Tail respectively.