Tool
Variance Calculator
Enter a true win rate and standard deviation to see the range of results that's normal over a sample. Find your standard deviation in your tracker (bb/100). Typical 6-max NLHE is 80–110; heads-up and PLO run higher.
20 simulated samples
Downswings within this sample
Chance that, somewhere in the sample, you drop at least this far from a previous high. Based on 2,000 simulated samples.
| Downswing of at least | Chance |
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How to read this
Results over a sample follow a normal distribution centred on your true win rate. The spread grows with the square root of the number of hands, so ten times the hands only makes the range about three times wider. That's why short samples say so little.
Risk of ruin assumes you keep playing the same stakes forever with no moving down and no deposits: RoR = e^(−2 · winrate · bankroll / SD²), with everything per 100 hands.
The biggest unknown is your true win rate. The win rate your tracker shows is itself an estimate with a wide range around it. Run the calculator a second time with a more pessimistic win rate to see how much that changes the picture.