Roulette Odds
Two numbers describe every roulette bet and people routinely confuse them. The first is how often it wins. The second is what it pays when it does. The gap between them is the house edge, and on a single-zero wheel that gap is identical for every bet on the layout.
House edge (noun): the share of everything you stake that a game keeps, on average, however the individual spins fall. On a single-zero roulette wheel it is 2.70% for every bet on the layout — a straight up and a bet on red cost the same per unit staked. It is a property of the wheel, not of the bet, the session or the player.
The roulette hub carries the full table of chances and payouts bet by bet, and how to play roulette explains what each of those bets is called and where the chips go. This page is about what those numbers do over a session rather than on one spin — which is the part that decides whether a night at the table feels like anything the odds predicted.
Why Every Bet Costs the Same
A straight up covers one pocket in 37 and pays 35 to 1. Were the wheel fair it would pay 36 to 1 — one unit for each pocket you did not cover — so the payout is short by exactly one unit, and that shortfall over 37 pockets is 2.70%.
Now take red: 18 pockets in 37, paying 1 to 1 where a fair wheel would pay slightly more. Work it through and the shortfall is the same 2.70%. Every bet on the layout is built the same way, which is why the last column of the hub's table is one number repeated.
The single exception is the five-number bet on an American layout — 0, 00, 1, 2, 3 — which pays 6 to 1 where the arithmetic calls for more. It is the only bet on either wheel priced worse than its neighbours, at 7.89%, and avoiding it is one of the three choices that actually change what you pay.
What a Session Actually Looks Like
Worked from the layout: the chance of missing 37 spins running is (36/37) multiplied by itself that many times. Note the second row — after a full 37 spins, one for every pocket on the wheel, your number has still not appeared more than a third of the time. That is not a cold streak or a tight table. It is what this bet is.
The Same Bet on Three Wheels
The same chips on the same square. The wheel under them is the whole difference, and it is the only one of these three numbers you get to choose.
Roulette Odds FAQs
2.70% per spin on a European wheel — one pocket in 37 — and 2.63% on an American one. It pays 35 to 1 either way, which is why the second wheel costs nearly twice as much to play.
48.65% on a single-zero wheel, not 50% — the green pocket is in neither colour. That missing fraction is the entire house edge, and it is why red and black pay 1 to 1 and still cost you 2.70%.
The comparable figure is the house edge, and a single-zero roulette wheel at 2.70% is cheaper than most slots, which commonly sit between 3% and 6%. What roulette does not offer is the long upside — a slot can return hundreds of times a stake in one spin, and the most a roulette bet pays is 35 to 1.
No. Each spin starts from the same 37 pockets regardless of what came before, so red is 48.65% after eight blacks exactly as it was before them. It is the most expensive belief in the game, and the strategy guide takes it apart along with the systems built on it.