Poker Variance Simulator

Last updated: 2026-07-14

Poker downswing and variance simulator. Project expected profit, confidence intervals, worst downswings, and risk of ruin from your win rate, standard deviation, and bankroll.

Expected result over 100k hands
5,000 bb
You'd expect to win about 5,000bb over 100k hands, though a bad stretch could still cost you.
Your Numbers
The Numbers Behind It
95% range
-1,198 to 11,198
bb — 19 of 20 runs land here
Typical swing
±3,162 bb
1 standard deviation
Chance of a loss
5.7%
finish below break-even
Chance you go broke (risk of ruin)
13.5%
2,000bb bankroll, all-time

What does a poker variance simulator show you?

A poker variance simulator projects the range of outcomes your win rate and standard deviation produce over a sample of hands. It reports expected profit, a confidence interval, the depth of typical and severe downswings, and the risk that your bankroll goes broke. The point is to separate normal bad luck from an actual problem in your game or your bankroll size.

How do you read the results?

The five headline figures are exact, closed-form calculations that update as you type. Expected profit is your win rate times the number of 100-hand blocks. The confidence interval widens with the square root of your sample. Risk of ruin and chance of loss come from the normal distribution of results. The Monte Carlo layer then plots thousands of individual trajectories so you can see the spread, not just the average.

MetricWhat it answers
Expected profitYour long-run result over the sample
95% confidenceThe band 19 of 20 runs land inside
Typical downswingThe median worst drop you should expect
Deep downswingA 1-in-20 severe drop to prepare for
Risk of ruinChance your bankroll ever hits zero

How much variance is normal for a winning player?

Far more than intuition suggests. A 5 bb/100 winner with a 100 bb/100 standard deviation can lose over tens of thousands of hands and still be a strong player. Standard deviation dominates results over any realistic sample; your edge only reliably shows up across hundreds of thousands of hands. The simulator makes that concrete by showing how often a genuine winner still finishes a stretch in the red.

How do you use variance to set a bankroll?

Your bankroll has to outlast the downswings your win rate guarantees. Enter your real numbers, read the deep-downswing figure, and keep a bankroll comfortably larger than it so a bad run does not end your play. Lower-variance formats need fewer buy-ins; high-variance games need many more. For a bet-by-bet view of the same trade-off, use our bankroll simulator and the Kelly criterion calculator. To reduce the variance itself, study spots with the hand equity calculator and manage tournament risk with the ICM calculator. The same discipline drives our live prediction market dashboard.

Key Takeaways

  • Variance is the swing around your win rate — even strong winners endure long, deep downswings.
  • Standard deviation dominates results over any realistic sample; edge only shows up across huge volumes.
  • Risk of ruin falls with a higher win rate or bigger bankroll and rises with higher variance.
  • Size your bankroll to outlast the deep-downswing figure, not the median one.
  • This is an off-table planning tool, grounded in the same math professional players use to survive swings.

Frequently Asked Questions

What is variance in poker?
Variance is the swing around your long-run win rate. Even a winning player loses many sessions and endures long downswings purely from the luck of the deal. The variance simulator projects the range of outcomes over a sample of hands, so you can separate normal bad runs from a genuine leak in your game.
How is risk of ruin calculated?
Risk of ruin is the probability your bankroll ever falls to zero before your edge compounds. The analytic estimate uses the diffusion formula RoR = exp(−2 × win rate × bankroll ÷ standard deviation squared). A higher win rate or larger bankroll lowers the risk; higher variance raises it. The simulator also measures ruin directly across thousands of trials.
What win rate and standard deviation should I enter?
Use figures from your own tracking software. Typical online cash win rates run from 2 to 8 big blinds per 100 hands for winning players, with standard deviation between 80 and 110 bb/100 for no-limit hold’em. Tournament and spin formats have far higher standard deviation. Enter your true numbers, not aspirational ones.
How big a downswing is normal?
Larger than most players expect. A solid 5 bb/100 winner with 100 bb/100 standard deviation can still face downswings of several thousand big blinds over a serious sample. The simulator reports the median worst downswing and a deep 1-in-20 downswing so you can size a bankroll that survives the bad runs your win rate guarantees you will hit.
Why does a winning player still show a chance of loss?
Over a finite sample, variance can bury a real edge. A 5 bb/100 winner over 10,000 hands still finishes below break-even a meaningful share of the time; over 1,000,000 hands that chance shrinks toward zero. The tool shows how the probability of a losing stretch falls as your sample grows.
Is the simulation exact?
The five headline figures — expected profit, confidence interval, standard deviation, chance of loss, and risk of ruin — are closed-form and update instantly. The Monte Carlo layer draws each 100-hand block from a normal distribution matching your inputs, the same central-limit approach every mainstream poker variance tool uses, to map the full distribution and downswing depths.

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