What we mean by the psychology of poker is getting into your opponents' heads, analyzing how they think, figuring out what they think you think, and even determining what they think you think they think. In this sense the psychology of poker is an extension of reading opponents' hands, and it is also an extension of using deception in the way you play your own hand.

Recently, while I was working on this Site, a friend ran up to me and said, "I made a great play in seven-stud last night at the Castaways." We had recently been talking about using deception by betting a second-best hand to make an opponent think you are stronger than you really are in hopes he will fold if you improve.

"Low card brought it in, and I called with a pair of kings," my friend began. "One of the kings was showing. Behind me a guy who was steaming and almost all-in called with an ace showing. He could have anything. Another guy, A.D., the best player in the games, raised with an ace showing. We all called.

"On fourth street I catch a 5. I have a king, 5 showing - still only a pair of kings. The guy who's steaming has ace, 10, and he bets. Maybe he has a small pair. The good player calls. Now I know for sure the good player has aces because he would never call another ace unless he had aces himself, especially with me sitting behind him with, maybe, two kings. He's played with me a lot, and he knows how I play.", "So you folded your pair of kings." "No, I raised!","That's pretty dangerous in that spot," I said."Well, I knew A.D. had aces," My friend continued, "and I knew he knew I knew he had aces. So when I raise, he has to figure that since I know he has aces, I must have made kings up. The guy who's steaming calls, and A.D. reluctantly calls. Then I get lucky. I make an open pair of Ss on fifth street, and I bet out. The guy who's steaming goes all-in, but A.D. shakes his head and folds his two aces because now he's worried I've made a full house - Ss full of kings. I end up winning the hand with kings and Ss against a pair of 10s. A.D. grumbled afterward that he's the one who should have been raising."

My friend did get lucky when he paired the Ss. However, in playing the hand he demonstrated the kind of thought processes that are the principal subject of this page. He went three steps beyond what he saw on the board. First, he thought about what his opponents might have. He tentatively put the steamer on a small pair, and with more assurance he put A.D. on a pair of aces. Then he went one step further. He thought about what A. D. thought he had - namely, a pair of kings. Then he went a step beyond that. He thought about what A.D. thought he thought A.D. had - and he knew A.D. knew that he thought A.D. had two aces. It was only after reaching this third level that he decided to raise with a pair of kings to make A.D. think he had kings up. Of course, it was also important that A.D. was a good enough player to think on a second and third level himself. Otherwise the play would make no sense. Just as you can't put a weak player on a hand, you can't put him on a thought either. A weak player might reraise with two aces, without analyzing the possibility that the other man might have kings up. Very sophisticated poker play can go considerably beyond the third level. An instance of such play came up at the Sahara in Las Vegas in a tough seven-card stud games.

The pair of 6s bet on the end; the A,K raised with aces and kings; and the pair of 6s called with 6s up. On the surface it may seem as if the 6s up made a sucker play in betting, that the aces and kings took a big chance in raising a possible flush or trips, and that the 6s up made another sucker play in calling the raise. In a typical game, the two small pair would no doubt check on the end, and the aces and kings might very well check behind him to avoid a check-raise. However, the thinking of the two players in this game was much more complicated. First, the 6•4• was betting all the way; that player knew, therefore, that his opponent put him on a four-flush. So with two small pair he bet for value on the end because he knew his opponent thought he had a four-flush, and he figured the opponent would call with one pair to snap off a bluff. The A,K took it a step further. He thought the pair of 6s might in fact be betting two pair for value because he knew the man with the two 6s thought he put him on a four-flush and that therefore the man with two 6s would bet two pair to get a call from one pair. So the A,K raised for value, thinking his opponent might think he was raising with only one pair. The man with the 6s up was hoping exactly that, and given the size of the pot, he felt his hand had enough of a chance to justify calling the raise. If the pair of 6s' first two up-cards had not been the same suit, the aces and kings would never have considered raising the bet on the end. At best, he would only have had a crying call because with two small pair the other player would probably have checked since he couldn't represent a flush draw. But with those diamonds showing each opponent was trying to outwit the other, and the aces and kings ended up getting the best of the situation. The 6s up didn't reraise, of course, representing a flush, because he knew that at that point the pot was so large his opponent would certainly call with something like aces up.

At the expert level of poker, the dialectic of trying to outwit your opponent can sometimes extend to so many levels that you must finally abandon psychology altogether and rely on games theory. It is precisely when judgment fails that games theory becomes so useful. However, in ordinary play against good players, you should think at least up to the third level. First, think about what your opponent has. Second, think about what your opponent thinks you have. And third, think about what your opponent thinks you think he has. Only when you are playing against weak players, who might not bother to think about what you have and who almost certainly don't think about what you think they have, does it not necessarily pay to go through such thought processes. Against all others it is crucial to successful play, especially when deception is a big part of the games.

• Calling and Betting on the Basis of What Your Opponent Thinks
• Psychology and Future Impressions