How we verify our answers

The verification pyramid

1. 1Arithmetic — checked by tests

   Outs, equity, pot odds and the rule of 2 and 4 come from code that runs on every commit. If a number in a lesson disagrees with the code, the build fails before it reaches you.

2. 2Preflop — checked against a published chart

   Opening and defending ranges come from one declared chart for 100bb 6-max. Lesson text is checked against that chart rather than against opinion, so “open this hand” means the same thing everywhere on the site.

3. 3Tournament spots — an ICM engine

   Push/fold, bubble and final-table spots run through an ICM calculator, with calling ranges that are themselves ICM-adjusted — not chip-EV shortcuts borrowed from cash games.

4. 4Contested postflop spots — a CFR solver

   When two strong players could argue either way, when the lesson is about bet sizing, or when the text quotes a frequency or an EV edge, the spot is solved with a CFR solver (TexasSolver) before it ships. No run, no number.

What makes a run trustworthy

• The ranges in the simulation match the published chart — for both players. A sim with invented ranges verifies nothing.
• The bet-size menu includes every size the lesson offers. You cannot validate “a third of the pot” in a simulation that has no third-pot option.
• The opponent model is written down. A defence range that is too tight is the fastest route to a confident wrong answer — it is exactly how we shipped two answers we later had to overturn.
• The accuracy target is recorded, and we never quote a frequency more precisely than that accuracy supports.
• Every solved spot keeps its record: the run, its date, and the output that decided the answer. No record means the spot may not call itself verified.

The solver decides what, a human writes why

A simulation can veto an action, a size or a number. It cannot explain anything. Every “why” on this site is written by a human and reviewed against the run, because the most common failure in poker content is the right answer with the wrong reason. Where the solver genuinely mixes two actions, we say so instead of presenting one of them as gospel.

What we don't claim

• The preflop chart is a deliberate simplification for 100bb 6-max — a compass, not gospel. It is not solver-derived.
• Not every spot needs a solver. Most are settled by arithmetic or by the chart, and we don't dress those up as simulations.
• When a chart or an opponent model changes, older runs go stale. Those spots are queued for a re-solve and carry no solver claim until it happens.
• This is training material, not gambling advice, and no verification method predicts your results at a real table.

Drift is caught by the build

Content and code ship together. The test suite asserts that every practice scenario still matches the spot it teaches — the board, the hero's hand and the answer itself — so text quietly drifting away from a verified answer fails the build instead of reaching you.

Common questions

Where this shows up