Heads-up is the purest form of poker: two players, every hand a blind battle, and no one else to wake up with a hand. At short stacks it's also one of the most solvable. Whether you play heads-up hyper-turbo Sit & Gos, the heads-up phase of a Spin & Go, or heads-up formats with antes, the same principles decide most of your results.
How heads-up works preflop
In heads-up the small blind is also the button. It acts first preflop and last on every postflop street. That position advantage is why the small blind plays a very wide range, and why the big blind must defend wide to avoid being run over.
The big blind's price
The numbers explain the strategy. If the small blind min-raises to 2bb, the big blind calls 1bb more into a pot of 3bb. That's a final pot of 4bb for a 1bb investment: the big blind needs only 25% equity to call, before accounting for position. Very few hands are that weak against a wide range.
With an ante in the pot the price improves further, and both players' ranges widen again.
Strategy by stack depth
20–30bb: limp, min-raise or jam
At these depths, solvers use all three options from the small blind. Limping is a large part of the strategy: it keeps the pot small out of the big blind's 3-bet range while still letting the button realise its position. Min-raises work with hands that want to build the pot but can handle a re-jam. The big blind attacks limps with raises and responds to min-raises with a mix of calls and re-jams.
10–20bb: re-jams take over
As stacks shrink, the big blind's re-jam becomes the key weapon against small raises, and the small blind has to choose between hands that can call a jam, hands that should jam themselves, and hands that limp.
10bb and below: push/fold
Below around 10bb, much of the game is push or fold, and the equilibrium jam ranges are very wide: well over half of all hands from the small blind at around 10bb, and wider as stacks get shorter. The big blind's calling range is tighter than the jam range, since calling needs real equity rather than fold equity. How these ranges are computed is covered in push/fold charts and Nash equilibrium.
| Stack | Small blind | Big blind |
|---|---|---|
| 20–30bb | Limp, min-raise, some jams | Raise vs limps; call or re-jam vs raises |
| 10–20bb | Limp, min-raise, jam | Re-jam heavily over min-raises |
| ≤ 10bb | Mostly jam or fold, some limps | Call jams with a tighter range |
Heads-up with antes
Antes add dead money to every pot. The extra money makes stealing more valuable and folding more expensive, so the small blind opens wider and the big blind defends wider at every depth. If you study heads-up formats with antes, use solutions built with the right ante size. A no-ante chart will be systematically too tight.
Common heads-up leaks
- Folding the big blind too much against min-raises, ignoring the 25% price.
- Limping without a plan for when the big blind raises.
- Calling jams too wide because the push range "looks" loose. Calling needs more equity than pushing.
- Playing 25bb like 100bb: flatting re-jams or making big raises that commit you without meaning to.
How to study heads-up
Heads-up rewards drilling more than almost any other format, because the same few spots repeat on every hand. Learn push/fold at ≤10bb first (small number of decisions, huge EV per mistake), then the limp and min-raise strategies at deeper stacks. Use a GTO trainer routine with short daily blocks, and run your hand histories against your strategy to find your leaks.
For the 3-handed part of the game before heads-up, see Spin & Go GTO strategy.
Frequently asked questions
How wide should the small blind shove heads-up at 10bb?
At equilibrium the small blind jams very wide around 10bb, well over half of all hands, and wider as stacks get shorter. The big blind's calling range is tighter than the jam range.
Should I limp the button in heads-up?
At 15–30bb solvers limp a large share of hands from the small blind. It works as long as you have a plan for when the big blind raises.
How do antes change heads-up strategy?
Antes add dead money, so stealing is worth more and folding costs more. Both the small blind's opening range and the big blind's defence get wider.