Double zero, written 00, is the second green pocket on a standard American roulette wheel. A conventional double-zero wheel has 38 pockets: numbers 1 through 36, a single zero, and a double zero.
The 00 pocket matters because standard roulette payouts generally remain the same even though the wheel has one more possible result than a single-zero wheel. That extra outcome raises the house edge on most ordinary bets.
Double zero changes the denominator
The easiest way to understand 00 is to count outcomes.
A single-zero roulette wheel has 37 pockets:
- 18 red numbers;
- 18 black numbers;
- one green 0.
A double-zero wheel has 38 pockets:
- 18 red numbers;
- 18 black numbers;
- one green 0;
- one green 00.
Consider a bet on black. The bet still covers 18 black pockets. On a single-zero wheel it loses to 18 red pockets plus 0, for 19 losing results. On a double-zero wheel it loses to 18 red pockets plus 0 and 00, for 20 losing results.
The payout on a standard winning black bet is still 1 to 1. The extra green pocket therefore worsens the player’s expected value.
Why 00 nearly doubles the standard house edge
For a standard even-money wager on double-zero roulette, the expected result on a one-unit bet is:
- win 1 unit on 18 outcomes;
- lose 1 unit on 20 outcomes.
So:
Expected value = (18/38 × +1) + (20/38 × -1)
That equals -2/38, or about -5.26%.
On single-zero roulette, the comparable calculation is:
(18/37 × +1) + (19/37 × -1) = -1/37
That is about -2.70%.
The difference is not because American roulette pays less on a winning red or black bet. It is because 00 adds another losing result while the 1-to-1 payout stays the same.
For the broader concept, see House Edge.
Standard inside bets are affected too
Double zero does not matter only to people who wager directly on 00.
A straight-up bet on one number covers one pocket. If the standard payout is 35 to 1, a double-zero wheel still has 37 ways for that bet to lose and only one way to win.
The same principle applies to splits, streets, corners, dozens, columns, red/black, odd/even, and high/low wagers: adding 00 increases the number of possible losing outcomes without proportionally increasing the normal payout.
That is why the standard house edge on most conventional bets on an American double-zero wheel is about 5.26%.
There is an important historical exception on the American layout: the five-number wager covering 0, 00, 1, 2, and 3 is typically worse than the standard bets because its payout does not preserve the same 5.26% edge. Players should check the actual rules and paytable offered at the table rather than assuming every roulette wager has identical mathematics.
00 is not red, black, odd, even, high, or low
The green pockets sit outside the usual even-money categories.
If the ball lands on 00, a normal wager on red loses. Black loses. Odd loses. Even loses. A 1–18 wager loses, and a 19–36 wager loses.
That is the point of the zero pockets in the standard game structure: they prevent the broad 18-number bets from being true 50/50 propositions while those wagers still pay 1 to 1.
The same is true of the single Zero on European-style wheels. Double-zero roulette simply has two such green results.
You can bet on 00 directly
Double zero is also a valid number position on the American roulette layout.
A player can normally place a straight-up wager directly on 00, just as on another single number. Under conventional roulette rules, a straight-up win pays 35 to 1.
That payout can sound large until the full probability is considered. On a 38-pocket wheel, one chosen number wins on only one of 38 possible pockets. The payout returns less than a fair-odds price would require, which is how the house advantage appears.
New Jersey casino regulations provide a useful formal example: the state’s roulette rules specify that a double-zero wheel has 38 equally spaced compartments. New Jersey casino game regulations.
Nevada-approved roulette rules also show conventional straight-up wagers paying 35 to 1 in roulette variants that include 0 and 00. Nevada Gaming Control Board roulette rules of play.
American and European roulette are not interchangeable labels
“American roulette” commonly refers to the 0-and-00 layout, while “European roulette” commonly refers to the single-zero layout. That distinction is useful, but a player should still inspect the actual wheel and rules.
Casinos can offer unusual roulette variants, electronic games, or additional pockets. Some single-zero games also use special rules such as la partage or en prison on qualifying even-money bets, which can further change expected value.
So the strongest comparison is not the marketing label. It is the actual number of pockets plus the actual payout and rule set.
See American Roulette and European Roulette for the wheel-type distinction.
Why the difference matters over repeated wagering
A difference between 2.70% and 5.26% may not be obvious during a short session because variance is much larger than the expected loss on a handful of spins.
Over total wagering, however, the theoretical cost diverges.
For $10,000 of comparable standard betting volume:
| Wheel type | Approx. standard house edge | Theoretical loss on $10,000 wagered |
|---|---|---|
| Single zero | 2.70% | about $270 |
| Double zero | 5.26% | about $526 |
These are expectations, not guaranteed session results. A player can win on either wheel. The table shows why the wheel choice matters mathematically when the rules are otherwise comparable.
The expected-loss relationship is simply:
Total amount wagered × house edge = theoretical loss
The phrase “total amount wagered” is important. A player who brings $500 can generate several thousand dollars in turnover by repeatedly re-wagering chips over many spins.
Double zero does not make streaks more predictable
Because 00 is visually distinctive, players often treat green results as signals.
After several red results, someone may say 00 is “due.” After 00 appears, another player may think another green result is now less likely.
On a properly operating roulette wheel, previous spins do not create that kind of simple debt between outcomes. The probability of 00 on the next spin comes from the wheel and game conditions, not from how long it has been since 00 last appeared.
A history board can accurately show what happened. It does not automatically become a forecasting tool.
What to check before choosing a roulette table
If two roulette games are available, compare more than the minimum bet.
Look for:
- how many green pockets are on the wheel;
- whether the game is single-, double-, or another zero format;
- the payout for the wager you intend to make;
- any special rules that apply to even-money bets;
- separate limits for inside and outside wagers.
If everything else is genuinely equal, the single-zero wheel normally gives the player better standard mathematics than the double-zero wheel.
Double zero and table limits are separate questions
The 00 pocket changes probability; the table limit changes how much money may be wagered. A $5 double-zero table and a $500 double-zero table have the same standard house edge if the wheel, payouts, and rules are otherwise identical. The larger limit increases the amount a player can expose, not the mathematical quality of the wager.
That distinction prevents a common comparison error: a high-limit room is not automatically offering better roulette odds. Always compare the wheel and rules separately from the posted betting range.
Double zero is therefore not a decorative American variation. It is an additional possible outcome that changes the price of the game. Understanding 00 means understanding why two roulette tables that look almost identical can have materially different expected costs.