What is GTO in Poker?

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GTO is short for Game Theory Optimal, which is the mathematically perfect way to play poker that makes it impossible to be exploited by opponents. In other words, if you play a perfect GTO strategy, your opponents could do no better than break even against you — and that would only be if they played a perfect GTO strategy themselves.

The actual GTO poker strategy is not yet known (and it may never be fully known due to the complexity of the game). However, certain aspects of the GTO strategy are known, such as using mixed strategies, balanced ranges, and multiple bet sizes in the same situation with different hands.

Poker Game Theory – How You Should Think About the Game

Poker has evolved rapidly in recent years. So much so that many strategy resources including some books, videos and digital content have become out-dated.

The most obvious change is that old-school players made their millions from exploitative play, whereas almost all players making millions now depend on poker game theory — with exploitative play mixed in — to take their game to the next level.

In this article, we’ll discuss:

The basics of game theory and poker
Why you should use a game theory-influenced strategy
An example from Doug Polk that highlights game theory’s importance
4 benefits of using game theory influenced strategy

Let’s get to it!

Game Theory and Poker

John Nash developed game theory as a branch of mathematics at Princeton University around 1950. As poker has become more popular over the last 15 years or so, players have improved dramatically, to the point where it’s very difficult to consistently to beat the game without game theory knowledge in your corner.

Understood mathematically, poker’s complexity runs deep — from the particular hand you open from each position, to a seemingly unimportant check on the river in a small pot, every decision influences your win-rate as a poker player. This can be measured by expected value (EV). If a decision is profitable it is said to be +EV, and if it is not profitable, it is -EV.

A very simple example of using a theoretically balanced strategy is when a player uses a range of open-raising hands. Below is an example of a typical opening range for a player UTG (first to act).

poker game theory optimal utg strategy

It is obviously a profitable play to raise our very strong hands UTG, but playing only those hands would be too predictable. By raising with some less profitable hands–like 9s8s or 6h6c–we balance our opening range, making us harder to play against. This way it’s still possible for us to have hit a very strong hand when the flop falls low or middling, like the one below

7s-spades-new-cards 6 spades poker game theory 5h gto poker

Why use a GTO poker strategy?

You might wonder why it’s important to play a game theory-influenced strategy when most of your money will be made by exploiting weaker players, or players who simply aren’t paying attention.

There are two main reasons:

With a balanced, GTO-based strategy, you will win money in the long run regardless of how skillful your opponents are.
Making adjustments to counter your opponents is easier if you have a baseline strategy from which to adjust (more on this later).

From a GTO point of view, your hand review sessions should involve analyses of how hands played out objectively. From that point of view you can decide if you played your range in a balanced way. Moreover, from a GTO standpoint you should know what you would do with any holding in any particular situation, not just the 2 cards you were in fact dealt. So, during review sessions you ought to ask yourself what you might have done with different holdings.

If you are betting for value in certain situations, you should also be betting as a bluff with other hands in your range so that your opponent is unsure whether you are betting for value or as a bluff. If you are only betting value hands on a certain river, your opponent can fold profitably every time knowing you have the goods. On the other hand, if you are bluffing too much in certain situations, then your opponent can call profitably every time knowing that you are less likely to have a strong hand.

If you’re still not convinced that a GTO-influenced strategy is the way to go, these hypothetical examples from Doug Polk should help:

Game theory poker examples

On the river you bet $100 into a pot of $100, so your opponent must call $100 to win $200. Thus, your opponent is getting 2-to-1 pot odds and needs to win at least 33% of the time to break even (learn how to calculate pot odds here).

This quick calculation reveals the optimal proportion of bluffs in your betting range on the river: 33% (one bluff for every two value bets). This frequency is optimal because it allows you to win the pot most often without the possibility of being countered.

Let’s test 4 different bluff-to-value bet scenarios so that you can see why a range with 33% bluffs and 66% value bets is the best option from a GTO standpoint, and there’s nothing you opponent can do about it.

(For simplicity, assume that we always win when our value bets are called, and always lose when our bluffs are called.)

Scenario 1 – Bluff 0%, Value Bet 100%:

Your opponent can fold 100% of the time. This results in you winning $100 with your betting range.

Scenario 2 – Bluff 100%, Value Bet 0%:

Your opponent can call 100% of the time. This results in you losing $100 with your betting range.

Scenario 3 – Bluff 50%, Value Bet 50%:

If your opponent calls 100% of the time, you win $200 when you are value betting and lose $100 when bluffing. This results in you winning $50 with your betting range only if your opponent always calls (50% * -$100 = -$50; 50% * $200 = $100. $100 – $50 = $50).

This scenario shows that not bluffing at all is actually more profitable than bluffing 50% of the time.

Scenario 4 – Bluff 33%, Value Bet 67%:

If your opponent always calls, you again win $200 when you are value betting and lose $100 when bluffing. This time, though, you lose $100 only 33% of the time and win $200 67% of the time, which comes out to a net profit of $100 (33% * $100 = -$33; 67% * $200 = $133. $133 – $33 = $100).

The bluff-to-value bet ratio used in this scenario is optimal because:

You win $100 if your opponent always calls
You win $100 if your opponent always folds

You make a profit of $100 regardless of whether your opponent calls or folds. This win-win scenario is only achievable with a perfectly balanced range. Your opponent is indifferent to calling and folding because no matter which option she chooses, your range profits the same amount.

Adjusting this ratio in order to exploit weak players can be even more profitable, but that requires careful and correct adjustments based on reliable evidence. If you want to move up in stakes and really crush the game long-term, understanding a GTO-influenced strategy is essential.

4 Benefits of Using GTO

Finally, take a look at these 4 general benefits that result from using solid GTO strategy.

1. Avoid Circular Thinking

A relic of poker training from the 90’s is trying to understand what “level” players are playing at.

Level-based thinking starts with you considering only your own hand.
Then it moves to thinking about what your opponent may have.
Then it moves to what your opponent thinks that you have.
Then it moves to what you think that your opponent thinks that you think that he has
And so on.

Ideally, you’d somehow determine where this “leveling” process should end up—that is, you’d determine on what level your opponent is playing and then adjust accordingly. But the reality is that this process is unreliable against weak players. And against more experienced players it could, in theory, repeat until the end of time, with both players trying to outdo each other’s level of thinking.

We can avoid ending up in this sort of situation by using a GTO-influenced bluffing strategy, which keeps us from confusing ourselves and getting into leveling wars on the flop with no equity.

2. Avoid Making Assumptions

Another benefit of a GTO-based approach to poker is that it forestalls potentially incorrect assumptions of other players. Of course, certain assumptions can be made if you’ve played against someone over a sufficient sample of hands, but making very general assumptions can be costly.

For example, it isn’t wise to say things like, “this is NEVER a bluff,” or, “he ALWAYS has it here.” Similarly, you shouldn’t assume an unknown opponent cannot have a certain hand in their range, or that they open very wide or very tight.

A well-constructed GTO strategy eliminates confusion, and helps you make the long-term profitable play.

3. Objective Analysis

Many players incorrectly judge how they played a hand by its outcome. But the further a player progresses into her poker career, the more she’ll come to realize that she’s not in the business of looking at results in a vacuum.

Yet, thinking objectively can be tough, especially when the result of a hand is either really bad or really good. Just because you hit your full-house on the river and stacked your opponent doesn’t mean that calling twice was the right play.

Once you’ve worked out what the correct GTO strategy was in a certain spot, apply it to your post session analysis to see if you made the long-term profitable play with your range, not just your 2 hole cards.

Every successful poker player knows that admitting mistakes to one’s self is absolutely crucial to consistently playing well. Game theory provides a foundation for discerning mistakes more easily.

4. It makes adjusting easier

Why is theory important when it comes to making badass adjustments in your strategy? To find out let’s play a little game.

Suppose you just forgot everything you know about poker strategy, except the rudimentary knowledge of the game, and you are just about to play your first hand ever.

Live $1/$2. $200 Effective Stacks.

Hero is dealt A♦ 9♦ in the big blind
folds to btn. BTN raises to $7. sb folds. Hero calls.

Flop ($14) A♠ T♦ 3♥
Hero checks. BTN bets $9. Hero calls.

Turn ($32) J♣
Hero checks. BTN bets $21. Hero calls.

River ($74) 9♣
Hero checks. BTN bets $50. Hero calls.

BTN shows A♥2♣. Hero wins $174 with two pair.

What do you make of the button’s aggressive line with his weak top pair? How could you adjust to exploit him in the future? Well, without understanding the theoretically correct way of playing his specific hand, you would not know where to start.

On the other hand, if you know the theoretically correct way to play A2o in the button’s situation, then you know how he is deviating from it. This knowledge makes it easy to deduce ways to exploit this opponent.

Here are the specific adjustments we can make to crush this player’s aggressive thin value betting strategy:

The small exploit: call down a bit lighter when he bets and barrels (but not too much).
The big exploit: relentlessly attack his check back range–which is apparently very weak–with big bets for thin value mixed with the appropriate amount of bluffs.

Very often, understanding the theoretically optimal way to play a hand makes exploiting your opponents’ easier because you know exactly how they are deviating from optimal. When you don’t know what is right, it’s nearly impossible understand what is wrong?

Conclusion

Striving for a perfect GTO strategy might seem like the logical conclusion, but the truth is nobody plays an entirely game theory optimal strategy. Poker has yet to be solved by man or machine, but we still highly recommend using game theory to influence your strategy as much as possible. As always, this means working on your game both on and off the felt.

This article is a very basic summary of how game theory is applied in poker, but hopefully you’ve gained something from it, or at least become more curious about how to develop your game in-line with game theory concepts.

For more on this topic, check out Doug Polk’s article on GTO vs Exploitative Play.

4 GTO Myths That Way Too Many Poker Players Believe

GTO? More like GT-NO!

Today we’ll be debunking 4 big myths about game theory optimal poker strategy, or “GTO,” as it’s now commonly called.

With insights from Ryan Fee and acclaimed poker writer Matthew Janda (from their new GTO module in the Upswing Lab), we’re determined to clear up these misconceptions once and for all.

A GTO strategy is a strategy that cannot be beaten in the long run, regardless of how our opponents play.

Myth #1 – The best players in the world currently use a GTO strategy

The GTO strategy for No Limit Hold’em exists, but is not yet known by any human, or even computer. The game is just too complicated, and hasn’t been solved. Less complex poker games, such as heads-up Limit Hold’em, have been solved (or at least essential solved).

GTO has become a buzzword synonymous with anything from “best possible strategy” to “good,” depending on the user. You might hear someone describe their steak dinner as GTO, or even their dog.

When you hear people talk about a GTO poker strategy, they probably mean to say a game theory-based strategy. Even veteran pros regularly get this wrong.

That said, we do understand some GTO concepts for some of the simpler parts of the game, and we recommend using them to construct your baseline strategy (more on this later).

Note: If you want to win at poker, you need a solid preflop strategy. This free Preflop Guide includes 8 easy-to-read charts and crucial tips that will help you play like a pro before the flop. Get it now!

Myth #2 – A GTO strategy would always take the most profitable line

Wrong. A GTO strategy is the strategy that maximally exploits an omniscient opponent. In other words, it’s the strategy that wins the most even if your opponent knows it perfectly.

A GTO strategy does not take into account the type of strategy an opponent is employing and thus is not always the most profitable strategy. For instance, a GTO strategy bluffs on the river against a calling station just as often as it bluffs against a nit.

Again, since poker is not a solved game, no player employs a perfectly optimal and balanced strategy. All players will be exploitable in some way, and some will be more exploitable than others. The most profitable line to take against opponents will involve maximally exploiting their imbalances through a specific counter-strategy.

However, exploitable plays have their own drawbacks. The two most significant are:

1. Sometimes your exploitative play will be wrong.

By definition, exploitable plays are a deviation from a theoretically optimal strategy. This is why it’s important to make exploitable plays based on reliable information–not assumptions. If you make exploitative plays based on assumptions, you will sometimes make massively -EV plays as a result of shaky information.

2. Whenever you make an exploitative play, you leave yourself vulnerable to being exploited.

Consider an example. We are playing online against a regular, and have a huge database of hands which shows that they over-fold from the SB versus 3-bets. Against this player, we are incentivized to 3-bet from the BB aggressively as we know the SB will fold often.

However, by making this adjustment we ourselves become unbalanced and open to being exploited. With any luck, the opponent we are attempting to exploit won’t notice that we are 3-betting a wide range, which could be punished by light 4-bets.

Myth #3 – You must be a master of math to use a GTO-influenced strategy

There is obviously math involved in playing optimal poker, but you don’t need to be a math expert to get your head around it.

Almost all of the calculations you need to know involve simple operations—there’s no need for algebra or linear equations and there’s no scary notation. The most commonly used formulas are available online. For example, you can read about two of the most important pieces to a game theory-based strategy here: calculating pot odds and minimum defense frequencies.

Working out things like pot odds and calling frequencies become easier with experience. Soon enough, it’ll be second nature and you’ll hardly need to think about them!

For example, the formula for calculating the optimal ratio of value bets/bluffs that you need based on your bet size is simple and can quickly be memorized. Let’s say we are heads-up and bet $100 into a $200 pot on the river, giving our opponent 3 to 1 odds on a call. In this instance, our betting range should consist of 75% value hands and 25% bluffs to make their bluff-catchers indifferent to calling or folding (the best they could do is break-even).

This ratio changes depending on our bet size. Here’s a table with a few of the most common bet sizes to help you remember them:

Size of Bet	Value Bet to Bluff Ratio
2x pot	2 bluffs for every 3 value bets
1x pot	1 bluff for every 2 value bets
0.75 pot	3 bluffs for every 7 value bets
0.5 pot	1 bluff for every 3 value bets

As the table shows, the smaller we bet, the more value hands we need to have, and the larger we bet, the more we should bluff.

Myth #4 – There’s no point to learning GTO since an exploitable strategy has a higher profit ceiling

While we’ve already established that an effective exploitative style will yield more expected value (EV) than a GTO strategy, this doesn’t mean you should disregard GTO altogether.

Playing in a well-balanced and optimal way is best when you know little or no information about your opponents. It often takes thousands of hands before you can confidently spot potential exploits in others, so it’s wise to employ a baseline strategy that protects you from getting exploited while you can gather this information. When you do pick up on potential exploits, then by all means devise a counter-strategy and feel free to deviate from your starting strategy.

Additionally, a sound understanding of GTO concepts will help you identify potential exploits in your opponents’ games. If you are well-versed in what an optimal strategy should look like, then you will be able to clearly spot when a player is deviating from it, and know how to punish them accordingly.

Time to GT-Go

GTO strategy is a complex topic that deserves more attention than we’ve given it here today, but hopefully we’ve cleared up some of the more common confusions.

Drop any comments, queries, or suggestions for future articles in the section below, and good luck on the felt!