What is MDF (minimum defense frequency) in poker?
Minimum defense frequency is how often you must continue (call or raise) against a bet so that the bettor cannot profit by bluffing with any two cards. MDF = pot ÷ (pot + bet). Against a pot-sized bet you must defend 50% of your range; against a half-pot bet, 67%.
Why it matters
MDF is the defender's mirror of pot odds. It doesn't tell you which hands to continue with — it tells you how much of your range must continue so you aren't exploitable by over-bluffing. In practice it's a ceiling on folding: fold more than 1 − MDF and an aggressive opponent should bluff you every time.
It's a guide, not a law. Against a player who never bluffs you should fold far more than MDF says; against one who bluffs too much, less.
The numbers
- MDF by bet size: one-third pot 75%, half pot 67%, two-thirds pot 60%, full pot 50%, 1.5× pot 40%, 2× pot 33%.
- 15.6% of the 147 players HoldemPro has diagnosed (23 players) have "folds too much" as their single biggest leak — the leak MDF exists to measure.
Figures come from the same preflop charts and research data the rest of the site uses (charts last updated July 5, 2026); they change when that data does.
Type the bet and the pot; get the break-even equity and a call/fold verdict.
You over-fold to small bets — losing pots you should have won by floating or calling down.
Common questions
How do you use MDF at the table?
Estimate the bet size as a fraction of the pot, get the MDF, and check whether the hands you'd continue with make up at least that share of your range. If you're folding much more than 1 − MDF, you're over-folding.
What is alpha in poker?
The bettor's side of the same math: alpha = bet ÷ (pot + bet) is how often the defender must fold for a pure bluff to break even. MDF = 1 − alpha.
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