Poker solvers for dummies part 5: post flop and ICM

The last part of our solvers for dummies series covers post flop play and an important concept for tournaments: ICM

derek kwan

Nov 30, 2022

Part 1: The basics

Part 2: Types of solvers

Part 3: The easiest solvers

Part 4: Adjusting to opponents

Part 5: post flop and ICM (you are here)

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I played a hand this weekend that I wasn’t quite sure I got right. It seemed a tad unnecessary when I had a deep stack in a soft field. I raised A9ss (two spades) in MP with ~50bb (avg was ~40bb), and a player with poor preflop selection but was solid otherwise called on the button. The flop came JsTs7c, giving me the nut flush draw and gutshot straight draw and overcard with an ace. However, this board hits my opponent’s range harder than mine, and we generally want to play more passively out of position, so I decided to check (what I would normally do in this spot), but go for a raise if bet into, due to the strength of my hand. I did check raise, and he jammed, and I pretty much snap called. He had flopped a straight with 89o (check to see if he played this correctly preflop on GTO Wizard!), and my flush didn’t come through.

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Well, I no longer have to wonder if I did the right thing, I can just check GTO Wizard! Let’s get to it. After selecting your prelop action, we see this prompt to select the flop cards:

We continue to choose our actions, just like we did preflop:

And now let’s look at what we should do with A9ss (by clicking A9s in the hand map):

You can see the correct play is to raise (12bb raise is preferred 71% of the time). So far, so good! Now the button goes all in. What’s the right decision?

Looks like the play I made was fine after all!

As I mentioned before, I believe everyone learns better practically, with real examples. So constantly try to remember hands that you played, and run them back on GTO Wizard as soon as you can to help check your lines, bet sizing, etc. This will naturally make you more curious to explore more hands. You can also even double check hands that are played on poker streams that you’re watching. And I also encourage you to watch GTO Wizard tutorials on YouTube, as there are a lot of things you can do, such as see EV (expected value) behind decisions, and many other options.

Now, let’s talk about ICM (independent chip model). Most understand this to mean “play tighter around big money jumps”, but there is a little more to understand than that. What ICM calculates is the value of your stack in terms of dollars at any given point in the tournament. It factors in what percentage of the total chips in play you have in your stack, what the prizes are, and what your opponents’ stacks look like. The calculation is quite complex, and not something people generally try to do while playing. It’s more important to understand the concept, rather than the actual calculations.

One important consideration is understanding how much chips are worth in terms of dollar value. If there is a 9 player SNG (sit n go) that pays 3 places, and first place gets 50%, one player can win a lot of pots and knock out a few players, and hold 80% of the chips in play. But that stack would not be worth 80% of the prize pool, because the max payout 1st place can get is 50%. The other players would absorb the rest of the equity, which shows how the fewer chips you have, the more each chip is worth. This generally means if you double your stack, you typically are not going to double your equity in the tournament. So there is mathematical reasoning behind why you want to protect a short stack near money bubbles: that short stack is worth a lot of equity!

Generally, in a situation where you are a middle stack with some big stacks and some short stacks, and you’re near a big money jump (usually late in a final table), you want to be careful not to bust before the short stacks. So you should play cautiously against the bigger stacks, but seek to apply pressure on shorter stacks when bigger stacks are no longer in the hand. Bigger stacks get to apply pressure constantly against the middle stacks most of all, while short stacks must balance getting blinded down with taking a risk with their short stack. How does this play out in reality with the hands you might choose to play? Luckily, GTO Wizard also has an ICM option on their solutions.

You can choose number of players, what phase of tournament, and select from a bunch of predefined stack sizes. Let’s choose 5 players, with one big stack. When the big stack (in the HJ) is first to act, you can see how wide the range is:

After the big stack raises, look how tight one of the middle stacks has to be!

The short stack in the small blind can play wider, but not by much. You can see how the SB seeks to put their stack to work by being quite aggressive with their jamming range:

The adjustments that need to be made in ICM situations can be super interesting, so take some time to play around with ICM ranges. If you are fortunate enough to make it the to the final few players in a tournament, knowing what to do when a lot of money is on the line will have been worth your time to prepare!

Ok, so this is the last part of my Poker Solver for Dummies series! But stay tuned as I’ll be writing a ton more on various topics around poker tournament strategy, and the use of solvers to back up what I’m saying will continue.

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