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GT-NO: Game Theory Optimal 101 and 201

Theory Of Poker Author Continues His GT-NO Series On Exploitative Play


David SklanskyAlthough this column will usually focus on tactics that are different than GTO (when you are playing mediocre or bad opponents), there is no denying that it is a powerful tool when you are facing competent opponents who don’t usually make major mistakes.

Likewise, it is a powerful tool for THEM when they are against YOU, especially in heads-up pots. Which is why much of my writing in my new book, and elsewhere, talks about manipulating your opponent away from tactics close to GTO that they are using wittingly or unwittingly.

But before continuing on this path in future columns, I think I ought to go into more detail about certain GTO concepts and how they turn into specific techniques. I am talking about situations where the bettor can be assumed to have either an almost certain winner or an almost certain loser.

Nowadays they call this being “polarized.” The guy is either bluffing or you definitely have him beat. When this is most likely the situation, there is a specific GTO strategy as to how often to bluff and how often to call.

When we are talking about the last round of betting, the GTO strategy is well known and easy to calculate. It’s GTO 101. First-year stuff. But not all readers may be familiar with it so I will explain it as succinctly as I can.

(Side note: When the polarized situation has apparently arisen with more than one round of betting to be played, it’s a bit more complicated, but still pretty easy to calculate with a pencil and paper. However, I am not so sure that most of the “new breed” know how to do this and may instead simply rely on their computers and solvers. In any case I am calling this situation GTO and will explain it in part 2.)

Of course, most poker situations are not simply “is he or isn’t he bluffing” which means that to stick to GTO you have to trust your computer. Trust it to come up with plays that can’t be exploited even if its strategy is known to the opponent. That would be GTO 301 and will be rarely discussed by me.

But not because it’s hard to figure out, but rather because you should rarely use it. It’s helpful to know it in order to get an idea how far your strategy deviates from it, but if you are in a game where it must be used often, you should probably change games or quit altogether.

it is the last round of betting, and you are considering calling someone who is obviously either bluffing or betting a hand you can’t beat, GTO usually insists that you call with a frequency that exactly matches the odds THEY were getting on their bluffs. That frequency depends on how much the player bet.

If they bet the pot, they are getting even money and will break even on bluffs if you call exactly 50% of the time. If they know that you will flip a coin to decide whether to call, they are INDIFFERENT as to whether they should bluff or not.

Telling them your method of deciding won’t help. Not if the coin is fair. If it was instead 51% or 49% and they knew it, they would have a counter strategy that exploits this knowledge. If the bet was half the pot, it would be 2-1 odds on the bluff so you would have to call two-thirds of the time, perhaps calling whenever you get a 1, 2, 3, or 4 on the roll of one dice.

There is an important exception though. If you think deviation from GTO is probably an improvement.

When it is you who is considering a bluff, you also look at the odds the opponent is getting just as they would, assuming you are both trying to play GTO. And again, the criteria is that you want to make them indifferent even if they know your strategy.

That means that if you bet the pot, you notice that they are getting 2-1 odds which means that your bluffs should be exactly half as frequent as your value bets (which we are assuming can’t lose.) If you bet half the pot, GTO wants the bluff to be one-third as frequent as the frequency of your unbeatable value bets, given he is getting 3-1.

Again, it may occur that the probability your hand is clearly better is high enough that when you add in the probability of a GTO bluff you go over 100%. Which would mean you always bet and they should always fold.

Next column, where I elaborate this concept of GTO in polarized situations with more than one round of betting, you will find that the existence of those future rounds makes the always fold strategy more common than you might think when facing the flop bet of a GTO expert. ♠

David Sklansky is the author of The Theory of Poker, as well as nearly two dozen other guides on gambling, poker, and other games. The three-time WSOP bracelet winner’s latest book, Small Stakes No-Limit Hold’em: Help Them Give You Their Money, is now available on Amazon. You can contact Sklansky at