Position-aware preflop fundamentals
Open the GTO Wizard preflop chart for a 6-max NLHE 100bb game. The screen shows six rectangles for six positions, each with a 13×13 hand grid colored by frequency. Most players treat these as memorization targets. They are not. They are the codification of a stack-aware equity-realization argument that you will internalize, then deviate from with reasons.
Chapter focus Internalize a position-by-position preflop framework that survives contact with NL10 reality.
Load-bearing idea
Preflop ranges are not arbitrary. Each position’s opening range is the set of hands that, given the players left to act behind, the depth of stack, and the equity each hand realizes given typical postflop play, has positive expected value to enter the pot for at the standard sizing.
The framework collapses into three forces:
- Equity — how often your hand wins at showdown against the range that calls
- Equity realization — what fraction of that equity you actually capture, given that you’re out of position vs in position, and given postflop skill differential
- Fold equity — what fraction of the time the players behind fold preemptively, conceding the blinds
UTG opens narrow because there are five players left to act, so the hand needs to be strong enough that calls from all five are still profitable, and because UTG plays out of position to most of those callers postflop. BTN opens wide because there are only the two blinds left to act, the BTN realizes nearly 100% of its equity in position, and the blinds defend with weak ranges.
Retrieval prompts
- Why does UTG open ~14% of hands in the standard 6-max NLHE chart?
- Why does BTN open ~50%?
- What is the difference between “equity” and “equity realization,” and which one is reduced more by being out of position?
- If villain at the BTN is a known nit who folds 80% to 3-bets, how does that change your 3-betting range from the SB?
Re-derivation log
Open GTO Wizard. Pick a hand at the boundary of UTG’s range — say, KJo. Note the indicated frequency. Then ask: at 100bb, against the population at this stake, why does KJo break even at this frequency? Articulate the answer in terms of the three forces above. If you can’t, the chart is just memorization, and you will leak EV the first time the texture shifts.