Preflop numbers that surprise players

Not rules of thumb, but frequencies computed for every hand.

Updated 2026-10-02 · numbers from the progressGTO solution book v13

Preflop charts tend to confirm what you already do. These five numbers are the ones that most often differ from what players expect. All come from our own approximation of equilibrium for 8-max tournaments with a 12.5% ante, chip EV, folded to the position shown.

1. The big blind folds only about 15% against the button at 20 BB

Facing a button open at 20 BB the book calls 62%, shoves 21% and folds 15%. The price is covered in big blind defence.

2. The button opens about half of the hands deep

At 100 BB the button plays 49% of hands; at 30 BB 46%. See opening ranges by position.

3. The small blind limps most of its hands at 60 BB

The book limps 81% of hands from the small blind at 60 BB and raises only 8%. At 25 BB it limps 58%.

4. UTG opens about one hand in six

At 30 BB, UTG opens18% of hands, about one in six. The chart is at UTG at 30 BB.

5. Raising stops being the main play around 12 BB

At 10 BB the button's opening is nearly all shoves (42% all-in, 0% raise). By 20 BB raises are 32% and all-ins 9%. See stack size zones.

A word of caution

The book is an approximation. It models the postflop game with a simple formula, it is not an exact solution of the whole game, and it keeps improving. Use it as a map and not a law, and check any spot you care about in the trainer.

Related guides

Questions