Two different probabilities
If the win chance is p, the loss chance is q = 1 − p. The probability that the next k rounds are all losses is qk. The chance of at least one such streak somewhere in a longer session is a different quantity.
At a 50% win chance, three losses in the next three rounds have probability 12.5%. At least one three-loss run in four rounds has probability 18.75%. Simply multiplying 12.5% by the number of possible starting positions double-counts overlapping runs.
How the exact calculation works
Let R(n) be the probability of a run of at least k losses in n rounds. R(n)=0 for n<k; R(k)=qk. For n>k: R(n)=R(n−1)+(1−q)qk[1−R(n−k−1)]. The tool evaluates this recurrence and counts overlapping runs correctly.
Assumptions and limits
Rounds must be independent and the win chance constant. This does not model changing settings, bankroll exhaustion, bet progression or dependence between outcomes. Inputs support 1–1,000,000 rounds and streak lengths 1–10,000. Results are rounded; extremely small values can reach floating-point limits.
Am I due a win after several losses?
No. Under independence, past results do not change the next round’s probability.
Does a longer session change the chance of the next round?
No. It gives more opportunities for a streak to occur somewhere in the session while the next-round chance stays fixed.
Read the full dice probability guide.
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