Streak survival probability
Probability of losing streaks of N in a row — shows variance is normal
How likely are losing streaks of 3, 5, 10, 15 in a row, given your win rate? Variance is harsher than most bettors realize.
Variance is normal
Even with a positive edge, losing streaks are mathematical certainties. A bettor with 55% win rate WILL experience a 10-loss streak somewhere in 500 bets. A bettor at 50% win rate will see streaks of 14+ losses. Knowing this in advance prevents tilt — when the streak hits, you don't panic-double stakes. This calculator runs the binomial math. Combine with Tilt detector for in-session monitoring and Drawdown calculator for bankroll risk.
The single biggest cause of bankroll death is being unprepared for normal variance. Most bettors who bust have positive edge — they just didn't expect 12 losses in a row.
See also: Drawdown calculator, Tilt detector, Kelly criterion
How to use
- 1Enter your win rate (or expected).
- 2Enter total bets in the period.
- 3See probability of streaks of 3, 5, 7, 10, 15.
- 4See expected longest streak.
Example: 55% win rate over 500 bets
55% win rate, 500 bets. P(at least one 5-loss streak) ≈ 99%. P(at least one 7-loss streak) ≈ 87%. P(at least one 10-loss streak) ≈ 39%. Expected longest streak ≈ 8 losses. Plan: if you bust on a 10-loss streak, it's not bad luck — it's predictable. Stake size for the worst-case streak you can endure.
When to use
- Before scaling stakes — know the worst-case streak
- Mental preparation for inevitable downswings
- Comparing win rates to required staking discipline
Frequently asked questions
What is the Streak survival probability calculator?
Even with a positive edge, losing streaks are mathematical certainties. A bettor with 55% win rate WILL experience a 10-loss streak somewhere in 500 bets.
How does the Streak survival probability calculator work in practice?
55% win rate, 500 bets. P(at least one 5-loss streak) ≈ 99%. P(at least one 7-loss streak) ≈ 87%. P(at least one 10-loss streak) ≈ 39%. Expected longest streak ≈ 8 losses. Plan: if you bust on a 10-loss streak, it's not bad luck — it's predictable. Stake size for the worst-case streak you can endure.
When should I use the Streak survival probability calculator?
Before scaling stakes — know the worst-case streak. Mental preparation for inevitable downswings. Comparing win rates to required staking discipline.