Most players know when to 3-bet – few know how much to 3-bet. If your raise sizes are off, even great hands lose value and bluffs lose credibility.
Solvers like GTO Wizard show that the right 3-bet size changes constantly by position and stack depth. Let’s break down why, and how to apply those adjustments in real games – with examples you can remember and use instantly.
- Read more: Multiway Muscle: Big-Bet Windows Revealed by GTO Wizard
- Read more: The Right Way to Study GTO Ranges: Stop Memorising, Start Understanding
Why 3-Bet Sizing Matters
Every 3-bet does two things:
- Builds the pot when you have the equity advantage.
- Applies pressure when you want folds.
If you size too small, you invite calls from hands that realise equity too easily. If you size too big, you risk burning chips when bluffing.
Finding the balance is about understanding position and stack depth.
Let’s Start with Position: The Closer You Are to the BTN, the Smaller You Can Go
Think of position as leverage. When you act last postflop, you don’t need to risk as many chips preflop to achieve the same fold equity.
| 3-Bet Spot | Common Size (vs 2.5x open) | Why |
|---|---|---|
| BTN vs CO | 6-7 bb (≈2.5×) | You’re in position; can realise equity easily. |
| SB vs BTN | 9-10 bb (≈4×) | You’ll be out of position; need to deny equity. |
| BB vs BTN | 9-10 bb (≈4×) | Same logic – out of position. |
| HJ vs UTG | 8-9 bb (≈3.5×) | Tight ranges; larger to isolate value hands. |
Rule of thumb: In position = smaller 3-bet; Out of position = larger 3-bet.
Example: BTN vs CO
- Blinds: 100/200
- Cutoff opens 2.5x (500)
- You’re on the Button with A♠J♠
Correct size: around 6-7 bb (1,200-1,400). You’re in position and want the CO to defend with worse hands you can outplay. If you make it 2,000 (10 bb), you price out dominated holdings like KJ or QJ that would otherwise call – reducing your future profit.
Example: SB vs BTN
- Blinds: 100/200
- Button opens 2.5x (500)
- You’re in the Small Blind with A♦K♦
Correct size: around 9-10 bb (1,800-2,000).
You’re out of position the rest of the hand. The extra size discourages calls with hands like 76s or KTo that play too comfortably with position.
Now Let’s Look at Stack Depth: The Deeper You Are, the Bigger You Go
When stacks are deep, opponents have implied odds to call and win big pots later. You need larger sizings to make those speculative calls unprofitable. When stacks get shallow, pot-to-stack ratios shrink – small 3-bets or jams become optimal.
| Stack Depth | IP 3-Bet | OOP 3-Bet | Key Idea |
|---|---|---|---|
| 100 bb+ | 3× | 4-5× | Deep – increase sizing to punish callers. |
| 40-60 bb | 2.5-3× | 3.5-4× | Moderate depth – blended sizings. |
| 20-30 bb | 2.2-2.5× or jam | 2.5-3× or jam | Shallow – small or all-in, clear decisions. |
Example: Deep Stack – 150 bb CO vs UTG
- Blinds: 100/200
- UTG opens 2.5x (500)
- You hold Q♣Q♦ Q♣ Q♦ in the CO
Correct size: around 9 bb (1,800-2,000). You’re deep enough that UTG will call some suited broadways and small pairs – hands that can win big pots if you let them in too cheap. The larger size forces them to fold or commit chips now, improving your EV.
Example: Short Stack – 25 bb BTN vs HJ
- Blinds: 100/200
- HJ opens 2.5x (500)
- You have A♠K♠ on the BTN
Options:
- Small 3-bet to ~6 bb (1,200) with a plan to call a shove, or
- Jam directly for 25 bb.
Both play similarly in EV – solver prefers the mix. The key is that smaller sizing sets up a clean shove-or-fold situation, not a messy postflop.
The Math Behind GTO Wizard’s Sizing
Solvers like GTO Wizard calculate raise sizes by making both players indifferent to calling or folding at the margin. As stacks get deeper or positions worsen, opponents’ equity realisation rises, so optimal sizings increase to compensate.
That’s why:
- Deep OOP 3-bets are large (4-5×)
- Shallow IP 3-bets are small (2.5-3×)
It’s a balancing act between fold equity, risk, and realisation.
Live Adjustments
In live fields, players often call too wide preflop and overfold postflop. That means you can:
Use slightly larger 3-bets across the board for more fold equity. Value-3-bet thinner – hands like AJo or KQo in late position perform better than the solver suggests. Avoid bloating pots OOP against sticky stations – smaller sizing retains flexibility.
| Situation | 3-Bet Size | Why |
|---|---|---|
| IP vs Late Open | 2.5-3× | Cheap, keeps worse hands in. |
| OOP vs Late Open | 4× | Deny equity, protect range. |
| Deep Stacks | Larger | Punish implied odds. |
| Short Stacks | Smaller or Jam | Simplify decision tree. |
The further out of position and the deeper you are, the bigger your 3-bet should be. Perfect 3-bet sizing isn’t about memorising numbers – it’s about understanding why those numbers exist.
Position and stack depth shift the math, but your goal stays constant: build pots when ahead, buy folds when behind, and always make your opponent pay the right price to play.
