At a glance
- On the HUD
- F4B
- Formula
folds / times they 3-bet and faced a 4-bet- Typical range
40–70%
- Where it shows
- Badge: the 3-bettor in 3-bet and 4-bet pots. Panel on your turn: when you 4-bet.
- Read hint
- Above: Folds too much to 4-bets: 4-bet bluff them. Below: Rarely folds to 4-bets: 4-bet for value only.
- Trust it after
- 12 chances. Below that the number is faded; reads need 12 chances and a number at least one standard error outside the typical range.
What it measures
Fold to 4-bet measures one decision. A player has made the 3-bet, someone 4-bets, and the action is back on them. They can fold, call or 5-bet; F4B is the share of those spots where they folded.
Typically the cutoff opens, the button 3-bets, the cutoff comes back over the top, and the button’s answer is recorded. A cold 4-bet from a third player counts too: the 3-bettor faces a 4-bet either way.
Don’t confuse it with fold to 3-bet, which is the opener folding one level earlier, or with 4-bet, which is how often the opener makes the 4-bet in the first place. F4B is about the 3-bettor, and it tells you how much of their 3-bet range is real. Its two siblings, call 4-bet and 5-bet, split up the rest of the same spot.
How it’s calculated
F4B = folds ÷ times they 3-bet and faced a 4-bet
- Chance: they made the 3-bet, and their next preflop action faced a 4-bet. A squeeze or a limp-reraise is a 3-bet too, so those hands count.
- Event: that next action was a fold.
- Not counted: hands where someone 5-bet before the 3-bettor acted again, and players who only called the 3-bet.
The HUD also keeps F4B in two narrower versions: in position against the 4-bettor (the 3-bettor would act last after the flop) and out of position.
Example: Dev 3-bet 70 times over a few weeks of games. He faced a 4-bet on 15 of them and folded 10 → 10 / 15 = 67%. Six of those 4-bets came from players he had position on, and he folded 2 (33%); out of position he folded 8 of 9 (89%). The overall 67% looks normal, but the split hints that he defends in position and gives up out of position. Both halves have fewer than 12 chances, so the HUD shows the overall number; treat the split as a hunch until it fills in.
Why it matters
F4B is the number that decides whether a 4-bet bluff makes money. Say you open to 2.5 bb in the cutoff, the button 3-bets to 9 bb and the blinds fold. The pot is 13 bb: your 2.5, their 9 and the 1.5 in blinds. A 4-bet to 20 bb puts in 17.5 more, so as a pure bluff it profits on the spot when they fold more than 17.5 / (17.5 + 13) = 57.4% of the time.
That break-even sits in the middle of the 40–70% typical range. A player at 70% hands you money with every 4-bet bluff; a player at 40% makes the same bluff a loser. Blocker hands like A5s keep some equity when called, so they need a little less.
It also tells you about their 3-bet range. A 3-bettor who usually folds is re-raising hands that can’t continue, like suited connectors and weak aces. One who almost never folds has a value range: treat their 3-bets as strong whatever their 3-bet percentage says.
The pots are big: a called 4-bet to 20 bb makes a 41.5 bb pot preflop.
Too low, about right, too high
Too low: under 40%
What it says
They rarely let go of a 3-bet. Either their 3-bet range is almost all value (QQ+, AK, maybe JJ), which is common among passive home-game players who only re-raise big hands, or they’re stubborn and call 4-bets with hands like AJ and KQ because they’ve already put chips in. Check call 4-bet and 5-bet to see which: a low F4B with a high 5-bet is a jammer; with a high call 4-bet it’s a caller.
How to exploit it
This is the HUD’s read for a low number: 4-bet for value only.
- Stop 4-bet bluffing them. A bluff to 20 bb needs 57.4% folds in the example above, and they fold well under that.
- If their 3-bet range is wide, widen your value 4-bets: QQ, AK, and sometimes JJ and AQs make money against a player who continues with worse.
- If their 3-bet percentage is low too, their 3-bets are simply strong: call or fold hands like TT and AQ instead of 4-betting.
- Against a caller, size your value 4-bets a little bigger, around 2.5x the 3-bet instead of 2.2x. They won’t fold the hands you want to get paid by.
About right: 40–70%
What it says
They fold a reasonable share and continue with the top of their range. Most 3-bettors with a mix of value and bluffs land here. Within the band, 40–50% suggests a value-heavy 3-bet range or a player who calls a lot in position; 60–70% suggests more 3-bet bluffs that give up to pressure. Either way, nothing here is a leak by itself.
How to exploit it
The 4-bet won’t print money on its own here, so look at the details:
- Check the in-position and out-of-position versions once each has 12 chances. Many players fold far more out of position.
- Compare it with your break-even: at 65%, the 4-bet bluff to 20 bb above profits by itself; at 45% it doesn’t.
- Bluff with blockers. In the middle of the range, 4-bet hands like A5s and A4s that block aces and play fine when called, not offsuit junk.
- Look past preflop. If they call 4-bets, how they play a low stack-to-pot flop (fold to c-bet) matters more than this number.
Too high: over 70%
What it says
They 3-bet plenty but can’t stand the heat. The usual profile is an aggressive player, often with a 3-bet above 12%, who re-raises light to win the pot preflop and gives up when the pot gets big. Their 3-bet range is full of hands that can’t call a 4-bet and that they won’t 5-bet as a bluff.
How to exploit it
The HUD’s read says it plainly: 4-bet bluff them.
- 4-bet bluff with suited aces (A5s–A2s), suited kings and a few offsuit broadways. At 75% folds, a 4-bet to 20 bb that gives up whenever they continue still makes 0.75 × 13 − 0.25 × 17.5 ≈ +5.4 bb each time.
- Keep the 4-bet small. About 2.2x the 3-bet does the job against a folder and costs less when they do have it.
- When they continue, believe them. A player who folds three times in four and then calls or shoves is showing you the top of their range.
When it’s your own number
Your own badge shows the same reads from the other side. If your F4B is high, the read is “4-bet bluff your 3-bets”, and every light 4-bet you fold to costs you your 3-bet. If it’s low, it says “4-bet you for value only”, which is fine as long as you fold the right hands to those value 4-bets.
To check yours, put it next to your 3-bet percentage. A 3-bet of 10% with a fold to 4-bet of 75% means many of your 3-bets are throwaway hands. Either 3-bet fewer pure bluffs (drop hands like K9s and QTo), or pick 3-bet bluffs that can call a 4-bet in position, like suited broadways. At tables that never 4-bet, a high F4B costs nothing; against an aggressive regular it’s a leak.
Using it on the HUD
F4B shows on the 3-bettor’s badge in 3-bet and 4-bet pots, using their position against the opener (the likely 4-bettor) until someone 4-bets, then against the 4-bettor. On your turn, when you can 4-bet, the panel lists the 3-bettor’s fold rate in or out of position against you, next to how often they 5-bet.
Above 70% the number turns gold, below 40% blue. It stays faded until it has 12 chances, and a narrow version with fewer than 12 steps back to the overall number (the tooltip says which). The read needs 12 chances and a clear miss: 10 folds in 12 (83%) makes the “4-bet bluff them” read, while 9 in 12 (75%) turns gold but doesn’t.
This spot is rare. If a player 3-bets about once every 20 hands and gets 4-bet one time in ten, that’s one chance every 200 hands, so 12 chances take around 2,400 hands, and at 12 chances a 50% number is still ±14 points (√(0.5 × 0.5 / 12)). Until then, use their 3-bet percentage and player type: a Nit’s or Rock’s 3-bet rarely folds; a LAG or Maniac with a high 3-bet often does.
Questions
What is a good fold to 4-bet percentage?
For most players, something inside the HUD’s typical range of 40–70%. Where you should sit depends on your 3-bet range: if you 3-bet many light hands you will fold more often, which is fine while opponents rarely 4-bet. Against players who 4-bet light, aim for the lower half by choosing 3-bet bluffs that can call or 5-bet.
How do you exploit a player who folds too much to 4-bets?
4-bet bluff their 3-bets. After a 2.5 bb open and a 9 bb 3-bet, a 4-bet to 20 bb needs them to fold more than 57.4% to profit on the spot, so a player folding 75% gives you about 5 bb each time even if you give up whenever they continue. Use hands with blockers like A5s and keep the size small.
Fold to 4-bet vs fold to 3-bet: what’s the difference?
Fold to 3-bet is the opener folding to a re-raise; fold to 4-bet is the 3-bettor folding when someone re-raises them again. They describe different ranges. Fold to 3-bet shows how much of an opening range gives up, while fold to 4-bet shows how many of a player’s 3-bets are bluffs.
How many hands do you need before fold to 4-bet is reliable?
Thousands, for most players. A regular might face a 4-bet once every couple of hundred hands, so 12 chances can take 2,000 hands or more, and even then a 50% number can be 14 points off. Until then, use their 3-bet percentage and player type.