Streak Sports Calculator
See the chance of win or loss streaks.
How to Use This Calculator
- Enter your single-bet win probability as a percentage (e.g., 55)
- Enter the streak length you’d like to look at
- Enter your total number of bets
- See the streak probability and your expected longest run
Formula
P(streak of N wins) = p ^ N
P(streak of N losses) = (1 − p) ^ N
Expected Longest Run (approx) = log(N · (1 − p)) / log(1 / p)
P(≥ 1 winning streak of length N in M bets) ≈ 1 − (1 − p^N)^(M − N + 1)
Frequently Asked Questions
Why does my expected longest streak come out so long?
Variance grows logarithmically with sample size. Over 1000 coin flips you’ll usually see a run of 9-10 heads. Long streaks feel shocking but are mathematically normal, and most bettors mistake them for hot or cold spells instead of plain old variance.
How does streak length tie into bankroll management?
Even a 60% win rate throws up 5+ losing streaks pretty often. Your bankroll plan (Kelly fractions, flat staking) has to soak those up without busting. Try a streak length of 5-7 here to see how regularly those losing runs show up and size your unit to match.
Are sports streaks actually predictive?
Mostly not. Independent events (coin-flip-style markets) create streaks by pure chance. There can be small predictive effects (injury cascades, team morale), but they’re usually overhyped. Treat past streaks as variance unless you’ve got solid, model-based reasons to think otherwise.
What's the math behind 'expected longest run'?
For independent Bernoulli trials with success probability p over N trials, the expected longest run of successes converges to log(N(1−p))/log(1/p). It’s a logarithmic approximation that holds up well for large N and gives the typical longest streak you’d see.