Heads-Up Preflop: When to 3-Bet and When to Get It All In
Heads-up preflop play is a fight over the blinds. The button opens a wide range, so the big blind defends with many hands and 3‑bets more often than at a full table, and stacks go in earlier. An ace in your hand changes a lot: it beats the many unpaired hands the button opens, and it makes it less likely that the opponent holds an ace. The hands to watch are bigger aces, which dominate yours, and most pairs.
Ace-four offsuit facing a heads-up open
In the big blind with A♦4♣, the button opens to 2.2bb. Fold, call or 3‑bet to 9bb?
See the answer
Before the flop, A♦4♣ against hands the button opens:
| Button's hand | A♦4♣'s equity |
|---|---|
| K♠9♦ | 59% |
| J♥8♣ | 57.1% |
| 6♥5♥ | 53.6% |
| Q♥T♥ | 52.3% |
| 7♣7♦ | 30.4% |
| A♠J♠ | 27% |
A♦4♣ is ahead of the unpaired hands without an ace and well behind most bigger aces and pairs. A 3‑bet makes many of the hands it beats fold or pay more, and the A♦ removes one of the aces the button could hold.
Ace-king suited facing a 4‑bet
Heads-up with 35bb effective, the button opened to 2bb, you 3‑bet to 8bb with A♣K♣ and the button 4‑bets to 18bb. Fold, call or jam?
See the answer
If the chips go in, A♣K♣ against hands that can 4‑bet:
| Button's hand | A♣K♣'s equity |
|---|---|
| A♥5♥ | 69.8% |
| A♦K♦ | 50% |
| Q♥Q♦ | 46.2% |
| J♠J♦ | 46.1% |
| K♥K♦ | 34.1% |
| A♠A♥ | 12.1% |
With 35bb, the 4‑bet already puts more than half the button's stack in. A♣K♣ is close to even against the pairs below kings and well ahead of a bluff like A♥5♥; only kings and aces leave it far behind, and its ace and king make those two pairs less likely.
Keep going
- Position and the price of defending heads-up: heads-up poker strategy.
- The same ideas at a full table: the preflop quiz.
- Why A♠J♠ dominates A♦4♣: dominated hands.
- How deep stacks change the plan: the stack-to-pot ratio.
- One spot every day: the daily poker puzzle.
- Which flops help the button and which help the big blind: button vs big blind.
- The strongest unpaired hand: how to play ace-king.
- KQo facing a heads-up 3‑bet: offsuit broadway hands.
- A3o in the small blind with a short stack: weak aces.
- Opening K7s on the button: suited kings.
- Trash hands and the big blind price: the worst poker hands.
- Facing the big blind's 3‑bet on the button: facing a 3‑bet in position.
- The name of each raise: what is a 3‑bet.
- The two stats that describe an opponent: VPIP and PFR.
- The same A♣K♣, from the commitment angle: short stack strategy.
- When stacks get short, the game becomes shove or fold: the push fold chart.
Sources
- Every equity is computed by exact enumeration of all boards with the app's equity module, checked on October 11, 2026.
- The answers to the spots follow rules written by the app's author; they do not come from a solver.