Minimum Defense Frequency (MDF)
Minimum Defense Frequency Is The Share Of Your Range You Must Continue With So A Bluff Cannot Profit Automatically: Against A Pot Sized Bet It Is 50%, And Against A Half Pot Bet It Is 66.7%.
Math Lesson From Smarter.Poker, Updated
The Formula
MDF Is The Pot Divided By The Pot Plus The Bet. A Bettor Who Risks The Size Of The Bet To Win The Pot Shows An Automatic Profit With Any Two Cards If You Fold More Often Than The Bet Size Relative To The New Pot. Defending At Least The MDF Removes That Automatic Profit.
If The Pot Is 100 And The Bet Is 50, MDF Is 100 Divided By 150, Which Is 66.7%. If The Bet Is 100, MDF Is 100 Divided By 200, Which Is 50%. The Larger The Bet, The More Of Your Range You Are Allowed To Fold.
| Bet Size | Defend At Least | Fold At Most |
|---|---|---|
| One Third Pot | 75% | 25% |
| Half Pot | 66.7% | 33.3% |
| Two Thirds Pot | 60% | 40% |
| Three Quarters Pot | 57.1% | 42.9% |
| Pot | 50% | 50% |
| Twice Pot | 33.3% | 66.7% |
What MDF Is And Is Not
MDF Is A Benchmark Built On One Assumption: That The Bettor Could Be Bluffing With Any Hand. Against A Balanced Opponent It Is A Useful Guide To How Often A Range Should Continue. Against A Real Opponent It Is Only A Starting Point, Because Real Opponents Do Not Bluff At The Rate A Benchmark Assumes.
If A Player Rarely Bluffs, Defending At The MDF Means Calling With Hands That Are Simply Beaten, And Folding More Is Correct. If A Player Bluffs Too Much, Defending More Than The MDF Wins Money. The Number Tells You Where The Line Sits, Not Which Side Of It Your Opponent Lives On.
MDF Also Says Nothing About Which Hands To Defend. It Is A Quantity For The Whole Range. The Hands That Should Continue Are The Ones With The Most Equity And The Best Chance Of Improving Or Catching A Bluff, And The Ones That Should Fold Are The Ones That Would Lose To Every Value Bet And Beat No Bluffs.
MDF Across Streets
Applying MDF On Every Street Compounds. If You Defend Two Thirds Of Your Range On The Flop, Two Thirds Of What Remains On The Turn And Two Thirds Again On The River, You End The Hand With 29.6% Of The Hands You Started With. That Is Expected And Correct: A Range That Faces Three Bets Should Be Much Narrower By The End.
The Mistake To Avoid Is Under Defending Early, Folding So Often On The Flop That An Opponent Profits By Betting Any Two Cards, And Then Over Defending On The River With Hands That Should Have Been Released. MDF Is Most Useful As A Check On The First Of Those Two Leaks.
Keep Learning
- How Often A Bluff Must Work
- Pot Odds: How To Know If A Call Pays
- How To Defend The Big Blind
- Mixed Strategies And Frequencies
Poker Terms In This Lesson
Practise It On Smarter.Poker
The Answer Above Is Complete. When You Want To Drill It, These Are The Matching Training Tools.
- Play MDF Defender The Training Game For This Lesson.
- Open Jarvis Training Insights Jarvis Explains Your Training Decisions In Words.
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