How often do roulette streaks happen? 20 million real spins vs the maths

Everyone has a story about the night red came up ten times in a row. We wanted the real numbers. So we took every spin we recorded on 163 live roulette tables since February — 20,104,998 spins — counted every run of one colour, and set each length against what the wheel’s own odds predict.

• 14,843runs of 10+ of one colour
• 378runs of 15+
• 22longest: reds in a row
• 2.69%of spins were zero

Every streak in one chart

The bars are what happened on the tables. The line is the maths. For short streaks the two are indistinguishable: about 554,573 runs of five or more, against 553,061 expected. And it keeps matching far past the point where most people would call a streak suspicious.

How often each streak happens

“Once every” counts either colour. For red alone (or black alone), double it: ten reds or more in a row turns up about once every 2,710 spins.

What that means at a table

The fastest live tables deal more than 100 spins an hour. At that pace a run of ten of one colour comes along every 14 hours or so of play — something a regular sees, not a once-in-a-lifetime event. Across all 163 tables we counted about 57 runs of 10+ a day, and 1.5 runs of 15+ a day.

Past 18, streaks get genuinely rare. Twenty or more happened 4 times in 260 days; the longest was 22 reds on Greek Roulette on 28 September. The full list of records — zero droughts, numbers that went missing for 600 spins, five-in-a-row repeats — is in live roulette records.

Streaks of 10, 15 and more are running somewhere right now. See them on the live board →

Red, black and zero

The shares behind the streaks match too. Red came up on 48.63% of spins and black on 48.68%, against 48.65% each on paper. Zero: 2.69%, against 2.70%. For how often each number lands, table by table, see the most common roulette numbers.

How rare was Monte Carlo’s 26 blacks?

On 18 August 1913 the ball at Monte Carlo landed on black 26 times in a row. In all of our 20.1 million spins the odds give a run that long about 0.07 times — so not seeing one is exactly what the maths says. You would need about 275 million spins to expect one: roughly 10 years of live roulette at the pace we record it.

How we counted

A streak is a run of one colour; a zero ends it. A run counted only if every spin inside it arrived on time — within three times the table’s normal interval, never more than four minutes apart — and only if it ended inside the data on both sides, so its true length is known. That rule throws away a few of the very longest runs (a long run is more likely to touch a pause), which is why the last bars sit a little under the line.

The expected line uses the plain odds of a single-zero wheel: 18 red, 18 black and 1 zero out of 37, each spin on its own. The one double-zero table we track is left out. Dates are UTC. The rest of the method is on the methodology page.