Why short stacks are genuinely solved
A full postflop solve has to abstract: it picks a handful of bet sizes out of an infinity of them, and its answer is only optimal within that menu. Push/fold has no such problem. When the effective stack is small enough that any raise commits you, there are exactly two actions — shove or fold — and exactly two responses — call or fold. The game tree is tiny and the equilibrium can be computed exactly.
That is why push/fold charts from any credible source agree with each other almost cell for cell, while two postflop solves of the same flop can differ. There is only one answer, and everybody has it.
Under roughly 15 big blinds, deviating from a solved shove range is almost always a mistake. It is the one area of poker where "just do what the chart says" is complete advice.
How the ranges are derived
The calculation is a fixed point. For any candidate shoving range, there is a best calling range against it; for any calling range, there is a best shoving range against that. The equilibrium is the pair that are each optimal against the other, and it is found by iterating until the two stop moving.
Two quantities drive the whole thing:
- Fold equity — the chance everyone folds and you collect the blinds and antes uncontested. This is what makes shoving profitable with hands that are far behind any calling range.
- Equity when called — how your hand does in the pot you are committed to when somebody does call. This is what stops the shoving range from being every hand.
The balance between the two is why the ranges behave the way they do. Antes increase the pot you win uncontested, which raises fold equity, which widens shoving ranges considerably — an ante stage changes the correct strategy far more than most players adjust for.
How the ranges move with stack depth
The most useful thing to internalise is not the exact cells but the rate of change. Shoving ranges widen fast as the stack shrinks, and they widen fastest right where most players freeze.
| Effective stack | Roughly what shoves | Share of hands |
|---|---|---|
| 15bb | Pairs, suited aces and broadways, better offsuit broadways. | ~30% |
| 12bb | All aces, most suited hands, offsuit broadways down to K9o. | ~40% |
| 8bb | Any ace, any king, most suited hands, most pairs — nearly any two cards with a face or a suit. | ~55% |
| 5bb | Very close to any two cards. | ~75%+ |
The gap between the 15bb and 8bb rows is where tournaments are won and lost, and it is exactly the range of stacks where a player who has not studied this will fold hands that are clear shoves, blind down, and arrive at 5bb with no fold equity left. Folding K9o on the button at 8bb is not cautious; it is a straightforward loss of expected value.
Position moves the ranges as sharply as it does anywhere else. From under the gun at an eight-handed table you are shoving something close to the top 12% at 10bb; from the small blind against one player you are shoving over half your hands at the same depth. The chart shelf covers every seat and depth for the tournament track.
The calling side, which is tighter than you think
Calling a shove is a different calculation and it produces much tighter ranges. You have no fold equity — the chips are going in either way — so the only question is whether your equity against their shoving range justifies the price.
Against a button shoving 40% of hands, a big blind getting a typical price needs roughly 35% equity. That is a real constraint: hands like Q9o and A2o that comfortably shove from the button are marginal or losing calls facing one. The asymmetry — shove wide, call tight — is the defining feature of short-stack play and the thing most amateurs have backwards.
- A hand that shoves profitably from a seat is frequently a fold when facing a shove from that same seat.
- Suited hands gain relatively little on the calling side, because you are looking at raw equity in a pot going to showdown, not at implied odds.
- Pairs gain a great deal, because they are rarely a large underdog against anything.
Where the chart stops being right: ICM
Everything above assumes chips are worth their face value. In a tournament they are not. Chips you win are worth less than chips you lose, because the payout structure is flat relative to the stacks — this is the independent chip model, and it is the one thing that legitimately overrides a Nash push/fold chart.
ICM pressure tightens calling ranges dramatically and, near a pay jump, tightens shoving ranges too — particularly if there is a shorter stack at another table who may bust first. On a final table bubble, calls that are clearly correct in chip-EV terms become large mistakes.
- Early in a tournament, with a flat and distant payout structure, chip-EV push/fold charts are close to correct.
- On a money or pay-jump bubble, tighten calling ranges substantially, and be more willing to shove into opponents who are themselves under ICM pressure.
- As the shortest stack, ICM pressure on you is at its lowest — you have the least to protect, and should be the most willing to gamble.
This is the exception that proves the rule: it is the only situation in short-stack play where you should knowingly play a range the chart does not show, and even then the chart is what you are adjusting *from*. See GTO vs exploitative play for why the baseline still has to come first.
Learning them so they survive a real clock
Push/fold ranges are the most memorisable material in poker and the most time-critical to recall. You will face these decisions with a shot clock running, a stack you are watching shrink, and no chart open. Recognition is not enough.
The efficient approach is to learn thresholds rather than grids: for each seat, the stack depth at which each broad group of hands enters the shove. "Any ace by 12bb, any king by 9bb, any two broadway by 10bb" is a compressed chart you can actually hold, and it is accurate enough that the residual error is smaller than the error from hesitating.
Then drill them against a clock. The tournament track in the bootcamp deals short-stack spots and prices each decision against the solved range in big blinds — chapter one is free and needs no account, and the analysis report will show you which depth you are misplaying once you have a sample.
Frequently asked questions
What is a push/fold chart?
A push/fold chart shows the game-theory-optimal shoving and calling ranges for short effective stacks in tournaments, by position and stack depth. Below roughly 15 big blinds there is no meaningful postflop play left, so the game reduces to two decisions and can be solved exactly rather than approximated.
At what stack size should you start push/fold?
Push/fold becomes the dominant strategy at around 15 big blinds and is essentially the only strategy below 10. Between 15 and 20bb it coexists with min-raising, and above 20bb ordinary raise sizing takes over because there is enough left behind for postflop play to matter.
Why are calling ranges so much tighter than shoving ranges?
Because shoving wins the pot two ways — everyone folds, or your hand holds up — while calling only wins one. A shove profits from fold equity; a call has none, so it needs raw equity against the shoving range to justify the price. That is why a hand can be a clear shove from a seat and a clear fold facing a shove from the same seat.
Does ICM change push/fold ranges?
Yes, and it is the main legitimate reason to deviate from a chip-EV chart. Because tournament chips won are worth less than chips lost, ICM pressure tightens calling ranges sharply near a pay jump and can tighten shoving ranges too. Early in a tournament, with distant payouts, chip-EV charts are close to correct.
Do antes change shoving ranges?
Considerably. Antes increase the size of the pot you win uncontested, which raises fold equity and widens correct shoving ranges — often by more than players adjust for when the ante level begins.