Poker variance simulator
pokalab.comHow sure are you of your winrate?
You have a sample: a winrate over a number of hands. With the standard deviation above, here is where your true winrate probably lies.
Your true winrate, from your sample
pokalab.comWhat standard deviation should you use?
Every variance calculator asks for your standard deviation, and most players do not know theirs. Your tracker shows it after a few thousand hands. Before that, use what real regulars have: we measured it on every regular with 20,000 hands or more at a stake, at 6-max no-ante cash, room by room. On GGPoker, the typical regular goes from 76 bb/100 at NL25 to 90 at NL1000: a little higher as the stakes rise.
Regulars' standard deviation by stake and room (bb/100)
| Stake | GGPoker | iPoker | WPN | 888poker |
|---|---|---|---|---|
| NL25 | 76 69–84 | — | — | — |
| NL50 | 78 71–85 | 85 79–91 | 75 69–80 | 86 80–92 |
| NL100 | 81 74–87 | 87 80–94 | 75 69–81 | 89 85–94 |
| NL200 | 82 76–88 | 90 83–96 | 75 70–82 | 91 85–98 |
| NL500 | 83 78–89 | 91 87–96 | — | 94 86–97 |
| NL1000 | 90 84–97 | — | — | — |
| Stake | Typical | Middle half |
|---|---|---|
| NL25 | 76 | 69–84 |
| NL50 | 78 | 71–85 |
| NL100 | 81 | 74–87 |
| NL200 | 82 | 76–88 |
| NL500 | 83 | 78–89 |
| NL1000 | 90 | 84–97 |
Standard deviation in bb/100 of regulars’ results after rake: the typical regular in bold, then the range of the middle half of regulars. A dash: too few regulars with that many hands. PokerStars is not included yet: a defect in how its all-in cash-outs are recorded slightly understates its swings, and it is fixed in our next data refresh.
pokalab.comThe rooms differ more than the stakes. At NL200, the typical regular runs from 75 to 91 bb/100 depending on the room: the pools are not the same, and neither are the years our hands come from. Pick your room in the calculator.
How it works
- The model. Results over 100 hands follow a normal distribution with a mean equal to your winrate and a spread equal to your standard deviation, one block of hands independent of the next. It is the model every variance calculator uses, and it holds well for a regular’s results over thousands of hands.
- The simulation. 2,000 runs of the hands you chose, drawn 100 hands at a time (coarser past 200,000 hands). The bands show where 70% and 95% of the runs are at each point; “New runs” draws another set. Downswings and stretches without a new high are measured on those steps, so they are, if anything, slightly understated.
- The exact parts. The expected result, the ranges, the chance to be down and the observed winrate come from the formula, not the simulation. Risk of ruin is exp(−2 × winrate × bankroll ÷ SD²), with the winrate and SD in bb/100 and the bankroll in bb: the chance of ever losing the whole bankroll, playing forever at that winrate.
- The link. Your inputs are in the page’s address: copy it to share a result.
Questions
What is a normal standard deviation in poker?
For 6-max no-limit hold’em cash, the middle half of regulars measures between 69 and 98 bb/100, depending on the stake and the room; the typical NL50 regular on GGPoker sits at about 78. The room matters more than the stake: see the table above.
How many hands until I know my winrate?
More than most players think. At 3 bb/100 with a standard deviation of 78, it takes about 183,000 hands to be 95% sure you are a winner at all. The calculator gives the number for your own inputs under “Hands to prove it”.
What bankroll do I need?
It depends on your winrate as much as on the stake. At 3 bb/100 and an SD of 78, a bankroll of about 31 buy-ins keeps the risk of ruin under 5%; halve the winrate and you need twice as much.
Why do my results look worse than my winrate?
Because the median run of a winning player spends long stretches without a new high, and deep downswings are normal. Look at the downswing table: what feels like running bad is usually inside the 70% band.