BLUFF CATCHING
When to Call River Bets
📚 Minimum Defense Frequency (MDF)
MDF tells you how often you need to defend (call or raise) to prevent villain from profiting with any two cards. If you fold more than MDF allows, your opponent can bluff with 100% of their range.
MDF = Pot Size ÷ (Pot Size + Bet Size)
33% Pot
75%
50% Pot
67%
75% Pot
57%
100% Pot
50%
150% Pot
40%
Key insight: A bluff catcher is any hand that beats bluffs but loses to value. You need enough of them in your calling range to hit MDF, but not so many that you're calling too wide.
RIVER SPOT #1
Unknown
Your Hand
Board
Pot Before Bet
$120
Villain Bets
$80
Bet % of Pot
67%
MDF
60%
Hand History
Should you call with this bluff catcher?
You have: Top Pair, Weak Kicker
✓
Correct!
Your Hand Strength
Top Pair
Villain Type
Balanced
Bet Size / MDF
67% pot → 60% MDF
Pot Odds Needed
33%
Estimated Villain Bluffs
~40%
Verdict
Call is +EV