Variance Calculator
Load a tournament schedule and get the profit distribution over N samples: downswings, risk of ruin and the bankroll it takes to survive them.
v0.7.4
1. Schedule
Fill in your schedule — for every tournament you play set a name, type, buy-in, AFS, your ROI and your ITM rate. New rows are added with «+ Add». A real MTT session almost never consists of identical tournaments, so list them all for an accurate estimate. You can also import a ready schedule.
2. Simulation launch
Set the key inputs before the run — rakeback %, bankroll and how many tournaments go into one sample. The longer the distance, the deeper the estimate.
Volume needed to verify a chosen ROI
Not «is the player profitable at all», but a specific claim: suppose the long-run ROI after fees really is +X%. How many tournaments before that +X% is hard to mistake for ordinary variance?
Current answer: if the player's long-term ROI is +10 %, you need about 29 k – 37 k tournaments to be 95% likely to see it separate from zero. That is roughly 166 full fields of 200 players.
| If long-term ROI is | Play this many | Full fields |
|---|---|---|
| +30 % | 3.3 k – 4.1 k | 18.4 |
| +20 % | 7.3 k – 9.3 k | 41.4 |
| +15 % | 13 k – 17 k | 73.7 |
| ▸+10 % | 29 k – 37 k | 166 |
| +5.0 % | 117 k – 149 k | 663 |
| +2.5 % | 469 k – 596 k | 2.7k |
| +1.0 % | 2.9 M – 3.7 M | 16.6k |
| +0.50 % | 12 M – 15 M | 66.3k |
| +0.10 % | 293 M – 372 M | 1657.5k |
Ranges include the model's residual noise buffer. Near 0% ROI the required volume explodes, because a tiny positive result is almost indistinguishable from normal tournament variance.
Volumes assume a symmetric normal shape. Real MTT results lean right, so for tight targets the true range is a little lopsided — treat this as a ballpark.
Other calculators
The simulator answers the question about the long run. The maths of a single hand is what the other tools are for.
Bankroll
How many buy-ins your stake needs
Fold equity
Folds for bluffs, semi-bluffs and raises, MDF and balance
Value and bluffs
How many bluffs to hold per value hand
Line planner
How the pot grows street by street
Outs and pot odds
Draw equity and how much a call needs
Combinatorics
Range combos, blockers, board
Variance simulator
Monte Carlo over your tournament schedule
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