At a glance
- On the HUD
- 4BSz
- Formula
average 4-bet, as a multiple of the 3-bet (raise-to amount / 3-bet amount)- Typical range
Not colored on the HUD: it has no typical range, because a good number depends on the game. See “Too low, about right, too high” below.
- Where it shows
- Badge: the 4-bettor.
- 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
4-bet size tells you how big a player re-raises a 3-bet. It divides their 4-bet total by the 3-bet total. Over a 9 bb 3-bet, a 4-bet to 20 bb is 2.2x, a 4-bet to 27 bb is 3.0x, and a 100 bb shove is 11.1x.
At 100 bb the 4-bet is usually the last raise before an all-in, so its size reveals plans. A small 4-bet keeps room to fold a bluff cheaply; a big one, or a jam, commits the 4-bettor and tells you they aren’t folding.
It’s the size half of 4-bet and cold 4-bet, which count how often players 4-bet. On the other side, fold to 4-bet and call 4-bet show how the 3-bettor answers.
How it’s calculated
4-bet size = average of (4-bet raise-to ÷ 3-bet raise-to) over every 4-bet they make
- Sample: every 4-bet, meaning the third full raise of the hand, whether the 4-bettor was the opener or a cold 4-bettor.
- Value: the total they raised to, divided by the 3-bet’s total.
- All-ins count when they’re a full raise, which a 4-bet shove nearly always is.
- Not split by seat or position.
A raise that isn’t a full raise, like an all-in for less than a min-raise, doesn’t make someone the 4-bettor and adds no sample.
Example: Max 4-bet five times in a long session: four times to about 2.3x and once all-in for 100 bb over a 9 bb 3-bet (11.1x). His 4-bet size = (4 × 2.3 + 11.1) / 5 = 20.3 / 5 = 4.1x. Nothing about his normal 4-bets is big; one jam made the number look wild.
Why it matters
The size of a 4-bet sets both your price to continue and how much a bluff risks. Using a 2.5 bb open, your 3-bet to 9 bb and the blinds folded:
| 4-bet to | Multiple | You call | Equity to call | Their bluff needs |
|---|---|---|---|---|
| 18 bb | 2.0x | 9 bb | 9 / 37.5 = 24% | 15.5 / 28.5 = 54.4% |
| 20 bb | 2.2x | 11 bb | 11 / 41.5 = 26.5% | 17.5 / 30.5 = 57.4% |
| 25 bb | 2.8x | 16 bb | 16 / 51.5 = 31.1% | 22.5 / 35.5 = 63.4% |
| 100 bb, all-in | 11.1x | 91 bb | 91 / 201.5 = 45.2% | 97.5 / 110.5 = 88.2% |
Smaller 4-bets give you a better price and risk less as bluffs; a jam asks the most of a bluff, which is why it’s rarely one.
Too low, about right, too high
The HUD has no typical range or color for 4-bet size. These bands are ours, for stacks around 100 bb. Out-of-position and cold 4-bets tend to run bigger; under about 40 bb, almost every 4-bet is a jam.
Small: under 2.2x
What it says
They 4-bet small, about 2x. That’s the size of a player who wants room: they can fold a bluff cheaply, or invite a 5-bet shove from you with a value hand. It’s also a common beginner habit: the min-4-bet, made without much thought about what comes next. Small 4-bets often come with a wider range, so check 4-bet: frequent and small means bluffs are in there.
How to exploit it
- Call more in position. At 2.0x you need 24% on pot odds, so pairs and suited broadways you 3-bet for value can see a flop.
- 5-bet shove lighter when their fold to 5-bet is high. A small 4-bet is easy for them to give up.
- Expect more bluffs in a small 4-bet. At 18 bb a bluff needs only 54.4% folds, against 63.4% at 25 bb, so hands like AQ and TT that beat a bluff can continue.
- Don’t read small as weak against a trapper. Some players min-4-bet aces to invite a shove; showdowns tell you which kind you face.
Standard: 2.2–3x
What it says
The usual range: around 2.2x in position, up to about 2.7x out of position. On its own the number won’t tell you much about their range; frequency, position and stack depth do. Most players who 4-bet with any plan land here, so use it as the baseline for spotting the one hand that doesn’t fit.
How to exploit it
- Defend by 4-bet frequency. Against a rare 4-bettor, fold everything but the very top of your range; against a frequent one, call or shove more.
- Notice a 4-bet that breaks their pattern. A 3.5x 4-bet from a 2.2x player is a different hand.
- Plan your 5-bet as a shove. At 100 bb, a 5-bet after a standard 4-bet leaves too little behind to do anything else.
- Call only with hands that are happy to get it in. After a called 2.2x 4-bet, less than two pots are left behind, so most flops become all-in decisions.
Large: over 3x (often jams)
What it says
They 4-bet big or move all-in. A high average usually means jams: one 11x shove among five 4-bets drags the average past 4x. Players who jam 4-bets at 100 bb usually hold QQ+ or AK, sometimes JJ or AQs, and they’re rarely bluffing, because a 100 bb jam needs more than 88% folds as a pure bluff.
How to exploit it
- Fold more to their 4-bets. Against a jam range of QQ+ and AK, you need 45.2% to call 91 bb, and hands like JJ and AQ don’t have it.
- If they 4-bet often as well as big, cut your 3-bet bluffs, since each jam costs you the whole 3-bet, and 3-bet hands that can call a jam instead.
- When a big 4-bet isn’t all-in (say 3.5x, about 32 bb), the stack left behind is about the size of the pot after a call. Treat it like a jam: shove or fold.
When it’s your own number
4-bet size has no read, but it sits on your badge when you 4-bet and anyone can see it. If you jam some hands and min-4-bet others, observant players will learn which is which. Use one size for your whole 4-bet range in each spot: around 2.2x in position, about 2.5x out of position, and a jam only when stacks are short.
Check your average after a few sessions. A number well above 3x with deep stacks means you’re jamming a lot, which throws away the cheap 4-bet bluff: a 20 bb bluff needs 57.4% folds, a 100 bb jam 88.2%.
Using it on the HUD
4-bet size shows on the 4-bettor’s badge in a 4-bet pot, next to how often they 4-bet and their fold to 5-bet. It shows one decimal (2.4 means 2.4x the 3-bet) and has no color or read.
It’s the slowest size on the HUD to fill: one sample per 4-bet, and most players 4-bet rarely. A dozen samples can take thousands of hands, and until then one jam can swing the average by more than a full multiple, as Max’s did.
Read it with 4-bet, cold 4-bet and 3-bet size: a player who sizes up their 3-bets often sizes up their 4-bets too.
Questions
What is a standard 4-bet size?
At 100 bb, around 2.2x the 3-bet in position and about 2.5x out of position is a common baseline, with cold 4-bets often a little bigger. Under about 40 bb, a 4-bet is usually just all-in. The HUD shows each player’s average, with no typical range.
Is a small 4-bet a bluff?
Not necessarily. Small 4-bets risk less, so players often use them with a wider range that includes bluffs, but some min-4-bet aces to invite a shove. Pair 4-bet size with 4-bet frequency and fold to 5-bet: frequent small 4-bets with a high fold to 5-bet point to bluffs.
How much equity do you need to call a 4-bet jam?
It depends on the sizes. After a 2.5 bb open and your 3-bet to 9 bb, calling a 100 bb jam costs 91 bb to play for a 201.5 bb pot, so you need 45.2%. Against a player who jams only QQ+ and AK, hands like JJ and AQ fall well short.