Bubble factor, as a table
How Much Equity Do You Need to Call an All-In at a Given Bubble Factor?
For an all-in for your stack with nothing else in the pot, the equity you need is the bubble factor divided by one plus the bubble factor. A coin flip needs 60.0% at a bubble factor of 1.5, 66.7% at 2 and 75.0% at 3, against 50% in chips. The bubble factor is how much a pot costs you when you lose it for every dollar it wins you when you win it.
With dead money in the pot, start from the equity the call needs in chips, E0. Then the equity you need is BF × E0 ÷ (1 + (BF − 1) × E0), or in words: the bubble factor times E0, divided by one plus (the bubble factor minus one) times E0. If you don't have your bubble factor yet, the bubble factor calculator works it out exactly from the stacks and the payouts.
Bubble factor chart: required equity by bubble factor
Find your bubble factor down the side and the equity you'd need in chips along the top. Each cell is the equity you need to call once the money is counted.
| BF | Equity you need in chips (E0) | Risk premium at 50% | |||||
|---|---|---|---|---|---|---|---|
| 25% | 30% | 35% | 40% | 45% | 50% | ||
| 1.00 | 25.0% | 30.0% | 35.0% | 40.0% | 45.0% | 50.0% | +0.0 |
| 1.10 | 26.8% | 32.0% | 37.2% | 42.3% | 47.4% | 52.4% | +2.4 |
| 1.20 | 28.6% | 34.0% | 39.3% | 44.4% | 49.5% | 54.5% | +4.5 |
| 1.30 | 30.2% | 35.8% | 41.2% | 46.4% | 51.5% | 56.5% | +6.5 |
| 1.40 | 31.8% | 37.5% | 43.0% | 48.3% | 53.4% | 58.3% | +8.3 |
| 1.50 | 33.3% | 39.1% | 44.7% | 50.0% | 55.1% | 60.0% | +10.0 |
| 1.70 | 36.2% | 42.1% | 47.8% | 53.1% | 58.2% | 63.0% | +13.0 |
| 2.00 | 40.0% | 46.2% | 51.9% | 57.1% | 62.1% | 66.7% | +16.7 |
| 2.50 | 45.5% | 51.7% | 57.4% | 62.5% | 67.2% | 71.4% | +21.4 |
| 3.00 | 50.0% | 56.3% | 61.8% | 66.7% | 71.1% | 75.0% | +25.0 |
The first row is chip EV: at a bubble factor of 1 this all-in is worth the same in money as in chips, and you need exactly what the pot odds say. By 1.5, a call that needed 40% in chips needs 50.0%.
Risk premium: the extra equity a bubble factor costs
The risk premium is the gap: the points of equity a call needs above its chip-EV break-even. GTO Wizard defines it as the extra equity you'd need compared with a chip-EV pot-odds sum. Bubble factor and risk premium describe the same pressure, one as a ratio and one as a gap. At 50% the premium is +10.0 points at a bubble factor of 1.5, +16.7 at 2 and +25.0 at 3. It shrinks as E0 falls: at a bubble factor of 2, a call that needed 25% in chips carries a premium of 15.0 points.
How to work out E0 from pot odds
E0 is the amount you have to call divided by that amount plus everything already in the middle, the shove included. When two players are all in for the same stack and nothing else is in the pot, it's 50%. Dead money brings it down. Calling 2,300 into a pot of 2,700 needs 2,300 ÷ 5,000 = 46.0%.
Why the money needs more than the chips
At a bubble factor of BF, a chip you lose costs BF times what a chip you win is worth. So count the chips you risk BF times over and do the pot-odds sum again. If the call risks R chips to win W, it breaks even in chips at R ÷ (R + W), which is E0. Counting the risk at BF × R, it breaks even at BF × R ÷ (BF × R + W). Divide through by R + W and you get the formula above. BBZ Poker writes the same thing as BF × R ÷ (W + BF × R), and PokerStrategy gets there by dividing the pot odds by the bubble factor.
Worked example: calling on a sit-and-go bubble
A sit-and-go has four players left with 2,500 chips each, paying 50/30/20. Blinds are 100/200. The small blind moves all in and you're in the big blind. You have 2,300 left to call, and 2,700 is already in the middle, so in chips you need 46.0%.
Exact ICM, valuing the table if you fold, win or lose, says the call needs 61.8%. The formula gets close. The bubble factor for an all-in between two of these stacks is 1.875, and 1.875 × 46.0% ÷ (1 + 0.875 × 46.0%) = 61.5%. The 0.3 point gap is the dead money: the bubble factor was measured on an all-in with nothing else in the pot. Open this spot to see it and change the stacks.
The formula always runs a little light when you're the one who can bust, so it lets you call slightly too often, and more so the bigger the blinds are next to the stacks. At about four big blinds it's two or three points short. With very short stacks, or a tiny stack about to bust at another seat, run the spot in the calculator instead.
Typical bubble factors on the bubble and at final tables
All of these come from exact ICM. The Main Event final table rows use real payouts, and the last two real stacks. The rest use simple example stacks.
| Spot | BF | Coin flip needs |
|---|---|---|
| Sit-and-go bubble, four equal stacks, three paid 50/30/20 | 1.88 | 65.2% |
| Same sit-and-go, three left, everyone in the money | 1.33 | 57.1% |
| 3,000 calling 5,000, four left, three paid (the calculator's example) | 2.13 | 68.0% |
| 3,000 calling 2,000, same table | 1.31 | 56.7% |
| 2025 WSOP Main Event final table payouts, nine equal stacks | 1.57 | 61.0% |
| 2025 Main Event final table, the 58 big blind stack calling the 68 | 1.84 | 64.8% |
| 2025 Main Event final table, the leader calling the 15 big blind stack | 1.09 | 52.2% |
Being covered hurts most when you have a lot to lose. At the calculator's table, the 3,000 stack calling the 5,000 needs 68.0%, and calling the 2,000 needs 56.7%. The short stack is covered by everyone, but it has less to lose, and its bubble factors stay between 1.45 and 1.70. At the Main Event final table, the leader calling the 15 big blind stack needs 52.2%, about two points over a coin flip.
In a big field the numbers run lower until late. GTO Wizard reports a chart from the book Kill Everyone, where bubble factor was introduced, for a 10,000-player Sunday Million: the average bubble factor climbs to about 1.6 on the money bubble and 1.7 just before the final table. Satellites, where every seat pays the same, go off the top of the chart: the satellite bubble calculator has spots where folding aces is right, and the satellite safe stack tables show how many chips it takes to stop worrying.
Calling tighter on the bubble
The bubble hits calls harder than shoves. The shover risks the same bust when called, but also picks up the blinds every time everyone folds. The caller only has the showdown, so the whole bubble factor lands on the call. Two lessons in part ten take the two ends of it: Avoid the stack that covers you and Call the short jam wide.
Our push/fold chart is chip EV. Against the shoving ranges it assumes, its calling ranges are the widest you should go on the bubble, and the table above says how much to tighten from there. For how each stack's value is worked out in the first place, see ICM worked by hand.