Variance
How far results spread around the average: in tournaments, a very wide spread.
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- What it means
- Variance measures how much actual results differ from the expected result. It is reported here as a standard deviation, in buy-ins.
- How it is calculated
- For one tournament the simulator computes it exactly from the payouts and cash chances; over n tournaments it grows with the square root of n, while the expected profit grows with n.
- Worked example
- In a 500-player field with a 20% ROI one tournament has a standard deviation of about 6 buy-ins. Over 1,000 tournaments that is about 6 × √1000 ≈ 190 buy-ins, against an expected profit of 200.
- Why it matters
- It explains why good players have long losing stretches and bad ones have heaters, and why your sample needs to be large before you judge your results.
Try it: Variance and bankroll calculator
See also: ROI, Downswing, Bankroll, Standard deviation