Bet Sizing & MDF
Every bet size sets the odds: the equity a caller needs, the bluffs that keep you balanced, and how much of a range survives to showdown.
What every bet size requires
| Bet | Caller needsb/(1+2b) | Bluff shareb/(1+2b) | MDF1/(1+b) |
|---|---|---|---|
| Pot | 33.3% | 33.3% | 50.0% |
| 3/4 pot | 30.0% | 30.0% | 57.1% |
| 2/3 pot | 28.6% | 28.6% | 60.0% |
| 1/2 pot | 25.0% | 25.0% | 66.7% |
| 1/3 pot | 20.0% | 20.0% | 75.0% |
| 1/4 pot | 16.7% | 16.7% | 80.0% |
| 1/6 pot | 12.5% | 12.5% | 85.7% |
- Caller needs: equity required to call. The call puts b (the bet as a fraction of the pot) into a final pot of 1+2b.
- Bluff share: the bluff fraction of a balanced, polarized river betting range. Equal to Caller needs by design: a bluff-catcher's equity is the bluff share, so a balanced range bluffs exactly at the caller's price.
- MDF: minimum defense frequency. Defend less and any four cards can bluff you profitably.
The call-down ladder
Betting on n streets against an opponent defending at MDF leaves MDFn of the range that saw the flop at showdown.
| Bet | 1 streetMDF | 2 streetsMDF² | 3 streetsMDF³ |
|---|---|---|---|
| Pot | 50.0% | 25.0% | 12.5% |
| 2/3 pot | 60.0% | 36.0% | 21.6% |
| 1/2 pot | 66.7% | 44.4% | 29.6% |
| 1/3 pot | 75.0% | 56.3% | 42.2% |
| 1/4 pot | 80.0% | 64.0% | 51.2% |
Potting three streets means the range that calls you down is ~12.5% of where it started. Your hand must beat that range, not the flop range.