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Bet Sizing Math

The numbers behind every bet size: how much equity a call needs, how often a bluff has to work, and how the theory balances value and bluffs.

Caller needs equitypot odds
Minimum defense frequencycontinue this often vs a bluff
Bluff needs foldsbreak-even for a pure bluff
River bluffs in betting range

Common sizes

SizePot oddsMDFBluff needsValue : Bluff

The formulas

  • Pot odds (equity to call) = bet ÷ (pot + 2 × bet)
  • MDF = pot ÷ (pot + bet). Defend less than this and any two cards profit as a bluff.
  • Bluff break-even = bet ÷ (pot + bet). The fold percentage a zero-equity bluff needs.
  • River bluff share = bet ÷ (pot + 2 × bet) of a polarized betting range. This makes the caller's bluff-catchers indifferent.

These are the baseline. If a player population folds far more than MDF, your bluffs print; if they never fold, stop bluffing and value bet thinner. The adjustment should be as big as your evidence, and no bigger.