The problem is that when you try to put yourself in the other players’ shoes, it is hard if not impossible to leave your own shoes behind. You know too much about what you are planning to do in your next move and it is hard to erase that knowledge when you are looking at the game from the other player’s perspective. Indeed, that explains why people don’t play chess (or poker) against themselves. You certainly can’t bluff against yourself or make a surprise attack.
