Poker Double Barrel Chart
How often does a double barrel need to work? This poker double-barrel chart lists folds needed and villain MDF for common turn sizes — ⅓ through pot — into a $100 pot after your flop c-bet was called, plus when barreling beats checking. Pair it with the c-bet chart, the semi-bluff chart, the fold equity chart, the MDF chart, and the free bluff calculator.
Double-barrel sizing chart: folds needed and MDF
Setup used for every row: heads-up pot already $100 on the turn after you continuation-bet the flop and got called. Action is on you — you bet again (a double barrel).
| Second-barrel size (of pot) | Folds a pure barrel needs | Villain MDF | Bet into a $100 pot |
|---|---|---|---|
| 33% (⅓) | 25% | 75% | $33 |
| 50% (½) | 33.3% | 66.7% | $50 |
| 67% (⅔) | 40% | 60% | $67 |
| 75% (¾) | 42.9% | 57.1% | $75 |
| 100% (pot) | 50% | 50% | $100 |
Folds needed = bet ÷ (pot + bet). MDF = pot ÷ (pot + bet). They always add to 100%. Numbers assume a pure bluff (zero equity when called) heads-up.
The formula
Folds needed = bet ÷ (pot + bet)
MDF = pot ÷ (pot + bet) = 1 − folds needed
Identical arithmetic to a flop c-bet of the same size. A half-pot turn barrel still needs one fold in three; a one-third pot stab still needs one in four. What changes is the story: they already called once, so their range is stronger than facing the first barrel — light second barrels need a better reason.
Worked example: $100 pot, half-pot double barrel ($50)
You c-bet the flop and got called. Pot is $100 on the turn. You bet $50.
- Folds needed (pure): 50 ÷ 150 = 33.3%.
- Villain MDF: 100 ÷ 150 = 66.7%.
- Check: 33.3% + 66.7% = 100%.
Against a nit who folds 40% of flop-call ranges on a blank turn, a pure half-pot barrel clears. Against a sticky caller who almost never folds the turn, you need outs (see the semi-bluff chart) or you should check more. Try the calculator preloaded for a $50 turn barrel.
Worked example: $100 pot, one-third pot double barrel (~$33)
Same $100 pot, now a small second barrel of one-third pot (about $33).
- Folds needed: 33.3 ÷ 133.3 = 25%.
- Villain MDF: 75%.
Small turn barrels after a flop call only need a quarter of their range to fold, and you put less at risk when called or raised. The tradeoff: medium hands and draws continue cheaply — so on wet boards a larger size that denies equity can be better when you do barrel.
Double barrel vs c-bet vs float
Break-even fold % matches a c-bet or float of the same size. Roles differ. A c-bet is the first barrel. A double barrel is the second barrel after they called. A float is betting after you called their bet and they checked. Barrel again when the turn favors your range, when you want to deny equity, or when checking gives a free card you dislike. Otherwise give up and save the stack for better spots.
The multiway trap
Everyone behind you must fold. Two opponents each folding 40% leave a pure bluff winning only 16% (0.4 × 0.4). A half-pot second barrel needs 33.3% heads-up — multiway, skip most air barrels.
When to double-barrel small vs large
Small (⅓–½). Blank turns that miss their draws, heads-up, thin value, or buying cheap folds from overcards and weak pairs that called once.
Large (⅔–pot). Scare cards or wet textures where draws get the right price to a small stab, or polarized value that wants a bigger pot. Pure bluffs at these sizes need 40–50% folds.
Give up. Multiway pots, sticky callers, turns that help their calling range, no plan versus a raise, or when checking is clearer. Stack depth after: see the SPR chart. Oversized lines: see the overbet chart.
Want the full system? Unleash the Madman on Kindle (free with KU). A short LAG playbook covering when to fire, when to stop, and the Tilt Trigger System.
See it on Amazon →Double-barrel FAQ
What is a double barrel in poker?
A double barrel is betting the turn after you continuation-bet the flop and got called. It is the second barrel in a multi-street bluff or value line — not a probe after they checked, and not a float after you called.
How often does a double barrel need to work as a pure bluff?
Same formula as any bet: folds needed = bet ÷ (pot + bet). A one-third pot second barrel needs 25% folds; half pot needs 33.3%; two-thirds needs 40%; three-quarters needs 42.9%; pot needs 50%. Equity when called lowers the fold target — see the semi-bluff chart.
How is a double barrel different from a c-bet?
Break-even fold % for the same size is identical. Timing differs. A flop c-bet is the first barrel as the preflop aggressor. A double barrel is the second barrel on the turn after they called the flop. Their range is already filtered by that call, so light second barrels die more often than light flop c-bets unless the turn favors you.
What is MDF facing a double barrel?
Minimum defense frequency = pot ÷ (pot + bet). Facing a half-pot turn barrel, MDF is 66.7%. Facing a one-third pot stab, MDF is 75%. Fold more often than that and pure second-barrel bluffs print — sticky callers who never fold still punish light barrels.
When should you double-barrel small vs large — or give up?
Small (⅓–½) on bricks that miss their draws and when you want cheap folds. Large (⅔–pot) on scare cards that favor your range, wet boards that deny equity, or polarized value. Give up multiway, on blank turns that help their calling range, or when you have no plan versus a raise. Pair with the c-bet, semi-bluff, and overbet charts.