A 4-bet in poker is the second preflop reraise: someone opens, someone reraises (the 3-bet), and you raise again on top. It decides more big pots before the flop than any other play, and it is also the one most players get wrong — almost always for the same reason. They use it as an emotional reaction instead of a decision with a size and a range behind it.
How the counting works
The big blind is bet 1, the open is the 2-bet, the reraise is the 3-bet, and the next raise is the 4-bet. The count continues from there — 5-bet, 6-bet — though in practice there are full stacks in the middle by then.
Sizing, where the mistake starts
House rule, 100 big blinds effective:
- In position: 4-bet to 2.2x–2.5x the size of the 3-bet. You opened to 3 bb and got raised to 10 bb, so you make it 22–24 bb.
- Out of position: 2.5x–3x. Same example: 26–30 bb. You charge more because you are playing the rest of the hand blind.
That sizing does two things. It leaves about 76 bb behind into a pot of roughly 50 — an SPR near 1.5, so one flop and you are committed, which is what you want with premiums. And it charges enough for the bluff to work without risking three times the pot.
One warning about the small 4-bet trend (under 2.2x): against opponents who never fold, a small size gives them a price to call with hands that belong in the muck. At low stakes, the bigger 4-bet earns more.
The value range, no decoration
At low stakes the clean value 4-bet is QQ+ and AK. That is the list. It makes money on its own because when you get called you still hold plenty of equity: AA is around 87% against AK, and QQ is a favourite — a little over 55% — against that same AK people love to stack off with.
You widen to JJ and AQs only if the opponent reraises too much. "Too much" is a number, not a feeling: if his 3-bet from the button or the blinds is above 10%, his range is already full of hands that cannot take a second raise. You read that on the HUD, not from memory. Against a 4% 3-bettor, widening is donating.
Why A5s is the best bluff
A bluff 4-bet is not picked because the hand looks nice. It is picked for blockers. A5s blocks AA, AK and AQ — the exact hands that would call you — and it still has the wheel and the flush as a plan B when the call comes. Against a QQ+/AK continuing range it keeps around 30% equity: not a dead hand, a hand with a parachute.
A4s and A3s do the same job. KQo is a poor bluff by comparison: it blocks what folds and does not block what calls.
Frequency rule: a reg with volume 4-bets 2% to 4% of hands. At 8% you are not aggressive, you are exploitable, and anyone with your HUD open knows it.
When the 4-bet comes at you
This is where more money is lost than in making one. Three rules:
1. At 100 bb the continuing range is narrow: QQ+ and AK shove or call; JJ and AQs call only in position and against loose opponents; everything else folds. Yes, including the AQo you "cannot fold".
2. Under 40 bb effective there is no small 4-bet. Raising to 24 bb with a 38 bb stack commits you anyway, while handing your opponent a cheap fold. At that depth: shove or fold.
3. Speculative hands fold. Suited connectors need deep stacks and a small pot; a 4-bet removes both conditions at once.
The three mistakes that turn it into a leak
Bluffing the wrong opponent. Against a player who only reraises with premiums, your A5s does not win a pot, it gives one away. A bluff lives off the weak part of the other range; if that part does not exist, neither does the play.
Changing size by hand strength. Making it 30 bb with AA and 22 bb with A5s hands your range to anyone paying attention for two orbits. Same size, always.
4-betting out of pride. They reraised you three times in a row and the fourth one is no longer judgement, it is an answer. That is the moment to look at your stop-loss, not at your cards.
The lesson
A 4-bet is not a show of strength. It is a play with three parts — fixed sizing, a narrow value range, and bluffs chosen by blockers — and it only works with all three in place. And it comes with variance, like everything else: AK loses to QQ nearly half the time, and that does not mean the play was wrong.
Every big preflop pot you build is a pot the house takes a cut from, so the room and the deal you play on are part of your winrate too — that is how our club works.
To know your real 4-bet percentage and your opponents', you need a tracker: the ones we use are on the tools page.
What was your last bluff 4-bet, and how did it end? Tell us in the community. Join free.