Slow-playing GTO Heuristics

Ft. ♠ ♡ ♢ ♣ ♤

3-min read

Watching Finding Equilibrium’s recent video on YouTube made me recall a particular hand I played quite a while back in the online poker scene. These are my thoughts from a Game theory Optimal (GTO) Solver perspective.

Hand History (or what I can remember)

5/10BB Online No-Limit Hold'em - 6 max, 5 people were playing

Everyone’s playing relatively deep, with SB and BB at ~250BB, UTG at ~50BB, CO at 170BB, and Hero (BTN, i.e. me) at 100BB.

Background: Keep in mind I had just sat down at this table and usually drop my first buy in to get a feel of the table. I’m looking for any indications in the playing styles and my bankroll for a single session is 2/3x of the max. Hero has a loose-aggressive (LAG) image, raising a lot of flops.

Pre Flop: (1.5BB) | Hero is BTN and is dealt 66 pocket pair
1 fold, CO raises 1.5BB, Hero raises to 3BB, 2 folds, CO calls

Flop: (7.5BB) 96K two hearts | (2 players)
CO checks, Hero raises to 5BB, CO cold calls

Turn: (17.5BB) 9 | (2 players)
CO checks, Hero hits the full house but checks.

River: (17.5BB) brick, don’t remember the exact card but no heart | (2 players)
CO shoves, and I instantly call, taking down a decent pot in my first hand of the night.

Hero shows and wins 201.5BB. CO mucks.

Villain seemed to be a somewhat competent tight-aggressive (TAG), assumed I'm full of shit due to constant aggression. I cash out happily to the absolute disgust of the other players at the table and leave — I kid, I ended up losing my BI after a few hours :)


I later ran this through the GTO solver and it also ends up checking during the turn as I did. I wanted to break down why I checked analytically:

  1. MacroAnalysis (Determine overall tendency of the range)
    ft. Range advantage/ disadvantage, Position, SPR

  2. MesoAnalysis (Determine hand-strength class)
    ft. Nuttish/ mid-strength/ showdown/ non-showdown hands

  3. MicroAnalysis (Analyze the unique characteristics of the hand)
    ft. Incremental equity, blockers/ unblockers

You should generally walk down each analysis sequentially and if at any time it points to a mixed-strategy you move down an ‘analysis’.


I started by analyzing the overall strategy of the hero’s range. There was a positive correlation between the amount of checking the range is doing overall and the number of combinations that are being slow-played and how much I was trapping.

The turn was not favorable for him (obviously), which meant by extending the rope, he could end up tying his noose himself.

The solver mentioned that the best place to check after running out all possible turn cards, greatest check-frequency would be where straights complete and where the 9 / King pairs.

Turns that pair undercards, in particular, are usually unfavorable for pre-flop aggressors that c-bet on the flop, because much of the callers continuing range would be compromised of under-pairs, whereas the aggressors under-pairs would often prefer to check on the flop.

TL;DR The macro view is recommending to include some traps in our checking-line. The checking-frequency had increased to ~60%, and from a GTO standpoint, I had to do some amount of slow-playing.


The next step is to gauge the relative strength of the hero’s hand class v. villain's range. Ideal slow-playing class are nuttish holdings that do not require much protection.

Even though my full house is generally strong, it was particularly so because of my villain’s wide range and pre-flop aggression and this extremely wet board.

TL;DR Villain had the ideal candidate cards for me to exploit completely.


The solver tends to slow-play combinations that block villain’s continuing range and/ or unblocking weak portion of Villain's range.

Poker Jargon:

  1. SB: Small Blind. Forced to place a small blind and is last to act after a round

  2. BB: Big Blind. Posts the full big blind and is second last to act after a round

  3. UTG: Under the Gun. The player in the earliest position to act voluntarily

  4. MP: Middle position. Self-explanatory

  5. HJ: Highjack. Third last to act.

  6. CO: Cutoff. The player who is seated directly to the right of the button, and is second last to act

  7. Hero: Me. Generic name used for a player who is narrating the story

  8. BTN: Last to act. The button is to the right of SB and is the last to act with the best position at the table

  9. HU: Heads-up - when you’re playing against one other player only

  10. Villain: Opponent. The other player you end up playing against if it goes to HU

  11. LAG/ TAG: Loose-aggressive/ tight-aggressive player. Describes playing style.

Truer words have never been uttered before -