Risk of ruin
Risk of ruin is the probability you lose your entire bankroll before your edge plays out. It falls as your win rate, or your buy-in count, rises.
In short: Chance your bankroll hits zero.
- Category
- Variance
- Best use
- Session review and bankroll decisions
- Related page
- Risk of ruin calculator
Why Risk of ruin matters
Test the estimate with a lower assumed edge as well as the observed rate, since an optimistic input can understate risk. Variance terms matter because live samples lie for longer than most players expect. A graph can be up or down for months without proving very much. The value is not comfort; it is knowing whether the current stretch fits the model or points to a real leak.
Worked example
A 4 BB/100 winner with 30 buy-ins typically has a low single-digit risk of ruin. The useful part is not the label itself; it is the decision it changes. If the example changes your stake, stop-loss, review queue or next study block, write it cleanly in the log.
How to apply it
Keep the decision separate from the outcome. Use win rate, standard deviation and sample size to build a range, then compare the current run against that range. If the run is normal, keep logging and review spots. If it is outside the band, dig harder. For Risk of ruin, the practical question is whether the label changes a bankroll, session or study decision. If it does not change a decision, it belongs in a note, not in the headline read.
Overshove currently records sessions and results. Use the separate public variance calculator for illustrative scenarios. An in-app confidence band and leak review are still in development. Use the same spelling every time, then link it back to risk of ruin calculator so the page, calculator or guide beside the term does useful work.
Common mistakes
- +Calling every losing stretch a downswing.
- +Calling every heater a new win rate.
- +Letting a point estimate stand on its own without a confidence band.
Questions players actually ask
How should I use Risk of ruin in a session log?
Use Risk of ruin as a decision label, not decoration. Log the raw session first, then attach the term only where it explains a stake, bankroll, variance or study choice you can review later.
What is the common mistake with Risk of ruin?
The common mistake is reading the term without the sample and context behind it. In live cash, a clean label still needs stake, hours, stack depth, cost and result data before it tells you anything reliable.