Get Started with Poker Solvers in 11 Easy Steps

In the modern poker world, poker solvers are a widespread topic of discussion. But what exactly are poker solvers, and how do they work?

In this introductory guide to poker solvers, we’ll discuss the following -

What is a Poker Solver?

A poker solver is a type of calculator that can generate “GTO” (Game Theory Optimal) strategies for the game of poker. 

What is a GTO Strategy?

GTO stands for ‘game theory optimal’. A GTO strategy is an entirely unbeatable poker strategy that represents a mathematically perfect way of playing poker. 

This concept might sound incredible at first, but there are some downsides. 

Using a Solver

The steps to using a poker solver may vary slightly depending on the software. But the basic process remains the same:

1. Build a game tree (see What is a Game Tree below).
2. Input ranges for the players involved (see Selecting Ranges for the Solve below).
3. Run the solve and explore the results (see Using Solver Output below).

What is a Game Tree?

A game tree is a simplified representation of all the possible actions that may occur in a hand of poker. The individual points on the game tree where decisions occur are called decision nodes.

Example: Game Tree:

Solvers generally offer a game tree builder, which speeds up building a game tree by letting the user set various options.

Example: Game Tree Builder 

Selecting Ranges for the Solve

Once the tree has been built, we then need to input hand ranges for the players involved in the hand. The user will usually get a hole cards grid selector, which can be used to add cards to each player's range.

Example: Starting Range Editor 

There is not necessarily a right or wrong answer when choosing which ranges to use for the solve. But this is not to say that some approaches aren’t better than others. 

Here are some common approaches to selecting ranges:

How Does the Solve Work?

So how does the solver work once we have everything in place and click the solve button?

The solving algorithm is an iterative process. So, it runs the same process repeatedly, gradually refining the strategies each time. 

Eventually, the solver reaches strategies with no incentive for either player to deviate from their current strategy. In game-theory terms, this point is a Nash equilibrium and means that the solve is now complete. 

In most cases, it will take too long for the solver to keep running until it reaches a perfect Nash equilibrium. The solver allows the user to set an appropriate level of accuracy slightly short of the true Nash equilibrium. 

A Closer Look at the Algorithm

Want the technical details? The following is a quick overview of how the solving algorithm works under the hood.

1. Since the solver doesn’t know how to play poker, an arbitrary (random) strategy for both player 1 and player 2 is selected.
    
2. The solver adjusts player 1’s strategy to a small degree so that it is exploiting the weaknesses in player 2’s strategy and generating higher profits.
    
3. The solver then adjusts player 2’s strategy to a small degree so that it exploits the weaknesses in player 1’s strategy and generates higher profits. 

Using Solver Output

Solver output is pretty complex, and it is nearly impossible for a human player to use the strategies directly at the poker table.

One reason for this is that GTO poker strategies make heavy use of what are known as mixed strategies. The correct strategy for a particular hand may be mixed between different options. 

For example, a specific hand might require a raise 17% of the time, call 63%, and fold 20% of the time.

Example: Mixed Strategy Solver Output

Running Preflop Solves

It’s possible to use poker solvers to generate GTO preflop ranges. When running a preflop solve, providing the solver with ranges is unnecessary since we hope to get this info from the solve itself.  

Likely, most of the solver work we do will only involve postflop solves. The downside in solving for preflop ranges is that the process is a lot more intensive and requires significantly more powerful hardware. 

While a postflop solve can run on an average home computer, a preflop solve will likely require a very powerful custom system. Although it’s possible to build such a system at home (at quite a cost), a common approach is to rent a powerful cloud system for a period of time. 

Since the average player does not have the knowledge or resources to run a preflop solve, a common approach is simply to buy a set of pre-solved preflop ranges. It is even possible to find complete sets of solved preflop ranges online for free in the modern poker era.

Solved preflop ranges can improve our preflop strategy, and we can input them into our solver for running postflop solves.

What Are Pre-Solved GTO Solutions?

When a company offers “pre-solved GTO solutions”, they give their users the solver output directly. The user won’t need to get their hands dirty building game trees and leaving their computers on to process solves. 

What is a Neural Network?

It’s worth giving a quick shout out to neural networks since they often crop up in conversations about poker solvers. 

A neural network is not technically a poker solver. But both neural networks and solvers have the same ultimate goal: to calculate GTO solutions in various poker scenarios.

• A neural network does this by leveraging the power of machine learning. It plays trillions of poker hands against itself while slowly improving. In other words, it teaches itself how to play poker through trial and error and then stores those strategies for future reference.

Getting Started with Poker Solvers

Price tags on solvers vary quite dramatically despite many of them using surprisingly similar algorithms under the hood. 

It’s possible to find a free GTO solver that performs arguably as well as a commercial poker solver with a $1,000 price tag. Take your time to explore options and shop around. 

If any of the above information seems abstract, the fastest way to learn is to get started by running your first solve and seeing how everything works. 

You’ll then have taken the first step to become a much stronger poker player!