8 reds in a row: the odds — both of them
Will you see it? Session odds
| Session length | P(streak ≥ 8 at least once) | Expected count of such runs |
|---|---|---|
| 50 spins | 6.92% | 0.07 |
| 100 spins | 14.22% | 0.15 |
| 200 spins | 27.15% | 0.31 |
| 500 spins | 55.37% | 0.80 |
| 1000 spins | 80.28% | 1.60 |
Eight-runs hit roughly a third of long sessions — and every one walks a $5 Martingale past a $1,000 requirement. This is the wall’s usual address.
Why this streak matters: it’s a Martingale killer
Betting black through 8 reds on a $5 Martingale means your next bet is $1,280 — already past a typical $500 table max, so the system is dead before it can “recover”. Our million-session Martingale run shows exactly how often these walls arrive.
The fallacy checkpoint
After 8 reds, the next spin is still red with probability 18/37 = 48.65%. The wheel has no memory — streaks are what independence looks like, not evidence against it. The 1913 Monte Carlo table famously ran 26 blacks while the room bet ever-heavier on red; the episode named the gambler’s fallacy — its place in the game’s full timeline here.
Other streak lengths
3 in a row4 in a row5 in a row6 in a row7 in a row9 in a rowodds hub →