VSO News’ Dara O’Kearney Launches New Book: GTO Poker Simplified

  • The purpose of the book is to give players a digestible introduction to poker game theory
  • Dara and his friends made a killing in tournaments until they hit the European Poker Tour
  • EPT players were better than Dara and had unexploitable styles
  • A key hand against Randy “Nanonoko” Lew cemented the importance of GTO for Dara
  • Solvers can be great learning tools, though real-time solvers are bad for the game 
rock paper scissors
Dara O’Kearney’s new book, GTO Poker Simplified, takes the brain twisting out of poker game theory, making it easy to understand for newcomers. [Image: Shutterstock.com]

GTO Poker Simplified

Today marks the publication of my fourth poker strategy book, GTO Poker Simplified. Two of my friends, Andrew Brokos and Michael Acevedo, have already written best-selling GTO books, Play Optimal Poker (Brokos) and Modern Poker Theory (Acevedo). So why did I feel the need to write my own? I consider them two of the best game theory books on the market and mine is not in direct competition with them. I believe my book sits in the middle between the incredibly practical Modern Poker Theory and the remarkably theory dense Play Optimal Poker.

actionable heuristics for players taking their first steps into game theory

These books are so good that I initially saw no need to write my own book on GTO, and just recommended both books to all my students. However, I started to notice that many players came back and said they couldn’t really grasp the books without a basic introduction to GTO with practical poker examples, which was the genesis of my book. The goal is to present the key lessons from GTO in actionable heuristics for players taking their first steps into game theory or those who have previously struggled to get their head around it.

I believe that after reading this book, readers who have developed a thirst for GTO should go on to read or revisit those other books.

My personal history with GTO and solvers

For many people, learning GTO and using solvers is a mind-blowing experience. They have played one way for a long time and then are suddenly presented with a new, counterintuitive way of playing. There can be resistance along the way, especially if the player in question has had success with an exploitative style previously, but it can also open up exciting new doors. My co-author Barry Carter said that he loved working on this book because, for him, it was like learning poker from scratch again, with all the wonder and enthusiasm that comes with it.

For me, discovering solver technology was more a case of confirming the suspicions I had developed over a number of years as a professional poker player. I learned poker the way everyone did back in the day, which was trial and error. I would see what worked and what didn’t, and the lessons eventually became heuristics about how to play.

The first inkling I had that game theory could be applied to poker was after I read Harrington On Hold’em. There was a sentence that really jumped out to me where Dan Harrington talked about shoving as a bluff. He said that if you add 33% to your stack when the shove gets through, and if you have 33% equity on average when called, you only need the shove to work 33% of the time to be profitable. I looked at that sentence and realised that you can work out which hands are profitable to shove.

I had the eureka moment where I realized we were coming to an equilibrium

I worked with an equity calculator and a spreadsheet and created push/fold ranges using trial and error. It took six months and was rendered completely useless when ICMIZER came out.  I studied this sheet when I was an SNG grinder and it worked out really well for a while, but then the regulars started to notice I was pushing wider than I used to, so they adjusted by widening their calling ranges against me. I returned to the spreadsheet, fiddled with the ranges, and created a tighter adjusted shoving range based on their new calling ranges. They adjusted again by tightening up against me, so I adjusted by widening my ranges again. A few more iterations followed and I had the eureka moment where I realized we were coming to an equilibrium, which meant that we were going to arrive at a place where neither of us would deviate from our own strategy despite knowing each other’s ranges. Soon it would be a case of if I shoved wider, I would lose money, if they called wider, they would lose money, and so on.

This sent me down a rabbit hole where I started to learn about game theory and how it applied to poker.

GTO as defense against better players

Around this time, I was crushing the live poker scene in Ireland. Myself, Dermot Blain, and Jason Tompkins – for a few years there wasn’t a final table one or more of us didn’t make, and in some cases a couple of us were at the same final table. The three of us had such an edge, we estimate we all had live ROIs of 300%.

It was only when I started playing abroad on the European Poker Tour that I came up against players I had no idea how to play against. They were so much better than me. I could not get any reads on them at all or work out how to exploit them. I thought I could not compete, but I remembered the basic precept of game theory was to develop an unexploitable style. It doesn’t matter what they do, if you are unexploitable, they cannot beat you.

this wasn’t supposed to happen

I think the most important hand I’ve ever played in terms of my career happened during this period at EPT Berlin against online legend Randy “Nanonoko” Lew. It is folded around to me in the cutoff and I open with A8o. Nanonoko calls the Big Blind, he had me covered. The flop came 8-3-2 and he led really small, I thought, “this is easy,” and just called. The turn was a 6 and he led small again, so I called again. The river was a Q and he bet three times the pot and I was like, “what the fuck?” This wasn’t supposed to happen, he was supposed to check and then I would think about betting, or he would bet small and I would call again, where did this come from? This might have been the first time I faced an overbet in my career.

In my mind, I thought he was at it, he knows I have a weak hand and he is betting to take me off it, so I have to call because he is full of shit. But then I thought he was looking at some old guy he had never seen before and we can’t fold anything, he knows I have a pair and he bet big to get max value. These two conflicting thoughts were going through my mind, he knows my hand and he is trying to take me off it, or he knows my hand and he is trying to get max value. I ended up folding and I asked all the top players I knew what they would have done, half of them said “it’s Nanonoko – he is full of shit you have to call” and the other half said “you can’t even think about calling, it’s three times the pot.”

It came down to what people thought of Nano, not the hand.

Lesson learned

That started me thinking, what do we do in this scenario? I knew we can’t always call and we can’t always fold, because we would be exploited either way. So that got me thinking about game theory and I started going back to first principles. He bet three times the pot, so if we fold four-fifths of the time, he is going to win one unit four times and lose three units one time if he’s bluffing. Therefore, I have to call 25% of the time (otherwise he can profitably shove as a bluff always). So, I had to decide what hands I call with, as well as whether blockers came into play.

I fixated on studying how to be unexploitable

From that point on, I realized that elite poker was all about game theory. I continued with exploits against weak players, but for the other guys, I fixated on studying how to be unexploitable. I had to learn concepts like the types of ranges, board coverage, minimum defense frequency, blockers, and much more.

When the solvers arrived, I was already there. I was a very early adopter of solver technology and when Hold’em Resources Calculator came out, I didn’t need my spreadsheet anymore. When PIOSolver came out it just confirmed everything I had suspected from studying GTO.

This is not to say I didn’t learn from solvers. They have revolutionized my game and I continue to be amazed at some of the things I learn on a daily basis with them. They even gave me a framework for why my exploits worked, in particular when thinking about ranges and blockers.

The rise of the solvers and the demise of the HUD

It is no coincidence that the efforts by a lot of online poker rooms to ban Heads-Up Displays (HUDs) has coincided with the growth of solver technology. HUDs are all about exploitative poker as they show you the tendencies of your opponents. With no reads and no stats, poker is all about game theory. A good regular has to play a lot of tables to be profitable and you cannot pay attention to 12 tables at a time with no HUD, so the correct approach is to play as close to a GTO style as possible.

GTO should be your starting point for playing against unknown players

GTO is the starting point for all good training content these days, even if that content then goes on to be mostly about exploits. GTO should be your starting point for playing against unknown players and very good players.

There is a lot of doom mongering about GTO as the death of poker, and there are certainly a lot of exaggerations and misconceptions about GTO. There is a genuine existential threat in the form of Real Time Assistance (RTA) GTO solvers, but for the most part you should not worry about RTA. At the time of writing, a very credible source in this space estimates that the number of players who regularly use software like PIOSolver is under 1,000 and possibly closer to 500.

There are a lot of elite players who have never run a sim in their lives. They do, however, have access to people who run sims and the information trickles down to them. The solver guys are like miners who refine the information into heuristics on how to play. What took them hundreds of hours can be learned almost instantly by somebody else. That is what we aim to do for readers in GTO Poker Simplified: giving you some of the most reliable heuristics from the teachings of solvers.

You can find Dara O’Kearney’s new book, GTO Poker Simplified, here.