Outside Bets in Roulette: Odds, Edge and How to Use Them
Outside bets are roulette's low-variance zone: red/black, odd/even, high/low at even money, dozens and columns at 2:1. None of them is 'safer' in expected-value terms — on one wheel, every outside bet gives the house the same cut. What they actually control is variance, and that is worth understanding precisely.
Play provably-fair roulette →The even-money trio: red/black, odd/even, high/low
Three outside bets pay 1:1 and cover 18 numbers each. Red/black splits the 36 numbered pockets by color. Odd/even splits them by parity. High/low splits them 1-18 versus 19-36. On a single-zero (European) wheel there are 37 pockets, so each of these bets wins with probability 18/37 — about 48.65%. Note what is missing: the zero belongs to none of them. That single green pocket is the entire house edge; when it hits, every even-money bet on the layout loses (absent the special rules covered below). The even-money trio is where most roulette sessions live because nearly half of all spins pay, keeping bankroll swings shallow — but 'nearly half' is doing the house's work in that sentence.
Dozens and columns: the 2:1 tier
Dozens (1-12, 13-24, 25-36) and columns (the three vertical lines of the layout) each cover 12 numbers and pay 2:1. On a single-zero wheel each wins with probability 12/37 — about 32.43%. The expected value works out identically to the even-money bets: you win less often but get paid double, and the zero takes the same bite. Columns and dozens differ in composition rather than math — a column mixes numbers from across the wheel and the layout, while a dozen is a contiguous block of the layout — but the wheel does not care how the layout groups things. Choose between them for coverage patterns, not because one is mathematically better; it is not.
The uncomfortable truth: every outside bet has the same edge
Run the arithmetic on any single-zero outside bet and the house edge lands on the same number: 2.70%, which is exactly 1/37. Even money: win 18/37 of the time, lose 19/37, EV per unit = 18/37 minus 19/37 = -1/37. Dozens: win 12/37 of the time at 2:1, EV = 24/37 minus 25/37 = -1/37. The same holds for every inside bet too — straight-up numbers, splits, corners — all -1/37 on a European wheel. There is no bet placement, combination or sequence that changes it, because every payout on the board is priced as if the wheel had 36 pockets while it actually has 37. 'Safer' outside bets are safer only in the sense that outcomes cluster tightly around the mean; the mean itself is identical everywhere on the felt.
What outside bets actually buy you: variance control
If every bet has the same EV, why prefer outside bets? Session shape. Betting 10 SUI on red wins about every other spin, so a 100-spin session typically drifts within a modest band around minus 2.7% of total action. The same 10 SUI straight-up on a single number wins once per 37 spins on average — most sessions of 100 spins end well down, a few end massively up. Same expected loss, radically different distributions. Outside bets are the right tool when your goal is time at the table: more spins, smaller swings, entertainment per SUI. Inside bets are the right tool when your goal is a shot at a large multiple. Neither is a strategy for profit — roulette has no such thing — they are risk profiles, and knowing which one you are choosing is the whole game.
Pairing outside bets to shape a session
Combining outside bets tunes the distribution further. Red plus the middle column, for example, overlaps on four numbers, giving you spins that pay both bets, spins that pay one, and spins that pay neither — a smoother equity curve than either bet alone. Two dozens covered simultaneously means roughly 65% of spins return something, at the cost that each win nets only one unit against two staked. What no pairing can do is beat the zero: cover 36 numbers out of 37 and you have built a machine that usually wins one unit and occasionally loses many — with EV still exactly -1/37 per unit staked. Pairing is legitimate session design. Treating it as an edge is the oldest mistake at the wheel, and progression systems like the Martingale change the distribution, not the expectation.
En prison and la partage: the rules that genuinely cut the edge
One class of rule actually changes the math, and it applies only to even-money outside bets. La partage: when zero hits, even-money bets lose only half the stake. En prison: when zero hits, the bet is 'imprisoned' for the next spin and returned in full if it then wins. Either rule roughly halves the house edge on even-money bets — from 2.70% to about 1.35% on a single-zero wheel — making them among the best bets in any casino that offers them. The general lessons transfer everywhere: single-zero wheels (2.70%) beat double-zero wheels (5.26%, since the extra green pocket doubles the miss rate), and rules printed in small type can matter more than anything you do with your chips. Llamabet's roulette states its wheel and edge up front, the minimum bet is 1 SUI, and every spin's outcome derives from a server seed whose hash is committed on Sui before you bet and revealed after — so the number that decided your even-money bet is verifiable, not taken on trust. Payouts land in your wallet on-chain within seconds.
Frequently asked questions
What are the odds of winning red or black in roulette?
On a single-zero European wheel, 18 of 37 pockets are red — a 48.65% chance of winning an even-money bet. On a double-zero American wheel it drops to 18 of 38, or 47.37%. The green zero pockets are why the bet is not a true coin flip.
Are outside bets safer than inside bets in roulette?
Only in variance, not in expected value. Every bet on a single-zero wheel carries the same 2.70% house edge. Outside bets win more often with smaller payouts, so your bankroll swings less — but your average loss per SUI wagered is identical to betting straight-up numbers.
What do en prison and la partage mean in roulette?
Both are single-zero rules that soften the zero for even-money bets. La partage returns half your stake when zero hits; en prison holds the bet for the next spin and returns it if that spin wins. Either roughly halves the edge on even-money bets to about 1.35%.