The wetness parabola

The sizing-schemes lesson mapped board classes to sizes; this lesson explains the ENGINE underneath, following a published solver analysis (GTO Wizard, July 2024). Its core distinction: range advantage decides how OFTEN you bet, while nut advantage and the value of fold equity decide how BIG. Two questions dominate the sizing decision: who owns the nutted hands, and how much equity do the hands that would FOLD have against your value?

  1. Count the nuts on both sides.If villain holds many nutted combos, big bets run into check-raises; if they hold few, you can fire freely.
  2. Price the folds' equity.Folding out 25% equity is routine; folding out 60% equity hands pays for oversized bluffs.
  3. Audit your middle.Middling hands anchor sizing — many of them force your nuts down to small sizes for protection.
  4. Place the board on the parabola.Dry sits left (small), wet sits center (big), soaked sits right (small again).

Worked example: the parabola, end to end

The analysis walks button-versus-big-blind flops across the whole curve, and its findings invert the folk wisdom that "wetter means bigger":

Board classSchemeWhy
Dry, paired (e.g. Q-Q-6 rainbow)~33% pot, high frequencyFolds come from under-25%-equity trash (low-value fold equity); villain keeps sets and queens; ace-x and underpairs need their nutted hands betting SMALL to protect them.
Wet, two-toned broadways (K♥J♥7♦)75–125% pot, overbetsThe analysis shows 62% folds to the overbet — including top pairs near 60% EQUITY and gutshots — while the calling range carries almost no nutted hands. Fold equity is rich and nobody can play back.
Soaked monotone connectors (Q♦J♦T♦)Small again, half bettingNutted hands everywhere — nearly a THIRD of continuing combos are straights or flushes — so only dominated trash folds and middling made hands need protection. Big bets run straight into the top of the caller's range.

That U-shape — small, big, small again as boards get progressively wetter — is the parabola. It exists because fold-equity value rises then collapses, and because nutted hands migrate from rare to common as boards soak.