progressGTO

What the solution book knows and where it still differs

Book v17 · updated 2026-10-30 · page checked 2026-10-30

What it is

43 stack depths from 1 to 100 BB, 8-max tournaments, 12.5% ante from each player (1 BB in total), chip EV. It is our own approximation of an equilibrium: the preflop tree is solved, and what happens after a call is a model, not a full postflop solution. It is not an exact solve and we never call it one. At short stacks the model deliberately values the pot a little differently from strict chip EV, which makes calls and small-blind shoves tighter.

What is calculated directly, and what is not

  • 1–5 BB: push/fold ranges come from our own multi-player calculation (every player behind can call, sampled deals, averaged over many iterations), not from the book. Since 29 Oct 2026 the model values the pot a little differently from strict chip EV, on purpose, so it is not a pure chip-EV equilibrium: the big blind calls all-ins less often and the small blind shoves fewer hands. Values are sampled estimates (about 3 points per hand), so treat it as our own calculation, not an exact solution.
  • Your hands: hand histories you upload for review are processed in your browser and never leave it.
  • ICM trainer and calculators: the Malmuth-Harville model is computed exactly for the stacks and payouts you enter.

What we measured

  • 1–5 BB, book vs our calculation: at 4 BB the book plays fewer hands from early position (UTG 26 % vs 29 %) and more from the button and the small blind (button 50 % vs 48 %, small blind 85 % vs 78 %).

Where it still differs

  • At most three players in a pot: once three players are in, a fourth can only fold. A very strong hand behind a raise, a 3-bet and a call would really continue; the book does not model that yet (the tree is about four to ten times bigger with four players).
  • The small blind jams too often and raises too rarely at 10–30 BB; at 100 BB it limps a little more than a full solution would.
  • The opener goes all-in too often against a 3-bet at about 30 BB instead of calling.
  • Big blind defence against a small-blind raise is a bit too loose on all-ins and too tight on calls at 30 BB.
  • The button opens slightly less than it should at 50–100 BB.
  • At 10 BB and below the book keeps min-raises with a few premium hands (a trap) and some blocker hands; the rest jam or fold. This is deliberate, but a full postflop solution may choose differently.
  • The big blind against a small-blind limp goes all-in too often at 6–10 BB.
  • Anything after the flop in Full Hand is a model estimate, labelled as such.

How we improve it

A note on ICM

ICM models predict tournament results more accurately than a simple baseline model, but in one large study of tournament results they underestimate the results of players with larger stacks and overestimate those who are short-stacked (Kim 2025, arXiv 2506.00180). The ICM tools on this site use the standard Malmuth-Harville model, so they carry the same limitation. Try them in the ICM calculator and the bubble factor calculator, or read what ICM is.

Think a spot is wrong?

Tell us the stack, the position and the action line. We check it against our own calculation and fix the book where it is wrong. Message us on Discord or write to [email protected].

Open the trainer →