How often must you call to prevent your opponent's bluffs from being automatically profitable? Learn the principles of MDF and when to deviate from it.
Every time your opponent bets and you fold, they can profit by bluffing with any hand. The minimum frequency at which you must defend to prevent this is called MDF (Minimum Defense Frequency).
| Bet Size | MDF | Folding Allowed |
|---|---|---|
| 33% pot | 75% | Up to 25% |
| 50% pot | 67% | Up to 33% |
| 75% pot | 57% | Up to 43% |
| 100% pot | 50% | Up to 50% |
| 150% pot | 40% | Up to 60% |
MDF = 40 / (40 + 30) = 57%
Hero must call with the top 57% of their range
A♥T♠ = ace high. Does it fall within the top 57%?
Depends on Villain's bluff frequency — default is to follow MDF and call
MDF is built on the assumption that "the opponent bluffs optimally." When this assumption breaks down, you don't need to follow MDF.
If a tight player at a live low-stakes game makes a big river bet, it's almost always value.
Applying MDF to a flop c-bet while OOP leads to calling with too many weak hands. Since OOP equity realization is below 100%, folding more than MDF dictates is correct.
MDF is calculated assuming "zero-equity bluffs." In practice, bluffs often hold some equity through draws or high cards. In these cases, you can defend slightly less without making their bluffs automatically profitable.
In pots with three or more players, the defense burden is shared. You don't need to meet MDF on your own.
| Concept | Perspective | When to Use |
|---|---|---|
| Pot Odds | Hand-specific | "Is calling profitable with this hand?" |
| MDF | Range-wide | "What percentage of my range should I call with?" |
Source: Upswing Poker, GTO Wizard Blog
Log in to write a comment.
Don't give up just because your draw missed. Learn the math behind river bluffs and how to choose the right hands to bluff with.
Catching opponent bluffs on the river with weak hands. Pot odds, opponent bluff frequency, and range analysis to decide call vs fold.
A hand too weak to value bet but strong enough to beat your opponent's bluffs. Master pot odds calculation and range analysis to make profitable calls.
Rake is not just a cost. It changes pot odds and equity realization, compressing preflop ranges. We use calculations to see how much tighter you need to be, especially when defending the BB and calling 3-bets.
When should you bet only with strong hands and bluffs, and when should you include medium-strength hands? Master the fundamentals of range construction.
A good bluff blocks your opponent's strong hands and unblocks the hands they'd fold. Learn the principles of bluff selection preflop and on the river.
