The Extra Pocket Is the Whole Story
A North American roulette wheel carries 38 numbered pockets: 1 through 36, a single zero, and a double zero. The double zero is the difference that matters. It is not a decoration and it is not an extra chance to win. It is an extra pocket that wins for the house on almost every bet a player can make, and its presence changes the arithmetic on the entire layout.
The numbered pockets alternate red and black. The zero and double zero sit in green pockets, usually opposite each other on the wheel. The numbers are not arranged in numerical order around the wheel; the layout is designed to scatter high and low, odd and even, red and black so that no simple pattern dominates the rim. The betting felt, by contrast, lays the numbers out in three columns of twelve, with the zeros at the head of the layout.
When someone says a North American wheel has 38 slots, they are describing the double-zero variant. A European wheel has 37 pockets and only a single zero. The two layouts look almost identical at a glance, but the missing pocket on the European wheel is the single largest rule difference a roulette player will ever encounter.
What the 38-Slot Layout Does to the Odds
Roulette pays winning bets as if the zeroes did not exist. A straight-up bet on a single number pays 35 to 1, even though the wheel holds 37 or 38 possible outcomes. That gap between the payout and the true odds is the house edge. On a 38-slot wheel, the gap is wider than on a 37-slot wheel because there is one more losing pocket and the payouts do not change to compensate.
House edge and Return to Player (RTP) are complements: they sum to 100% for the same bet under the same rule set. RTP is a theoretical percentage of total wagered money a game returns to players over a very large number of spins or hands. It is a long-run statistical average, not a per-session guarantee. The house edge is the mathematical advantage the operator holds on a given game, expressed as a percentage of each wager.
For a straight-up bet on a North American wheel, the true odds against hitting one number are 37 to 1, because 37 pockets lose and one wins. The payout is only 35 to 1. That two-unit shortfall, spread across 38 pockets, is the house's cut. The same logic applies to every bet on the layout, though the size of the cut differs by bet type.
| Wheel type | Pockets | Zeroes | Effect on straight-up bet |
|---|---|---|---|
| European | 37 | Single zero only | One fewer losing pocket; smaller house edge |
| North American | 38 | Single zero and double zero | One extra losing pocket; larger house edge |
The extra pocket increases the house edge on the American layout. That is the entire structural difference, and it applies to nearly every wager on the felt. A player who can choose between a single-zero and a double-zero table is choosing between two different rates of expected loss on the same bets.
The Sequence of a Round
A round begins when the dealer, or croupier, opens betting. Players place chips on the felt, either on a single number, on groups of numbers, or on the outside sections that cover broad categories such as red, black, odd, even, high or low. Once the dealer calls an end to betting, the ball is launched around the rim in the opposite direction to the spinning wheel. From that moment no chips may be touched.
The ball loses momentum, drops onto the wheel, and settles in one pocket. The dealer marks the winning number on the felt with a marker, clears all losing bets, and pays winners. On a straight-up win the payout is 35 to 1 on the winning chip, while the original chip remains the player's. Split bets pay 17 to 1, street bets 11 to 1, corner bets 8 to 1, six-line bets 5 to 1, and the outside even-money bets pay 1 to 1. A bet on a column or a dozen pays 2 to 1.
Buy-in works like any other table game. A player places cash on the felt, never directly into the dealer's hand, and receives roulette chips in return. Roulette chips are often colour-coded to the player so that two people betting on the same number can be told apart. These chips have no value away from the table and must be exchanged for regular casino chips before leaving.
What Each Decision Point Means
Roulette looks passive compared with blackjack or craps, but the player still makes a series of decisions before every spin. The first is wheel selection: single-zero or double-zero. The second is bet type. The third is stake size. The fourth is when to stop.
Bet type is the decision that most changes the arithmetic. Inside bets cover specific numbers and small groups; they pay more and hit less often. Outside bets cover broad categories; they pay less and hit more often. Volatility describes how payouts are distributed over time. High volatility means rarer but larger payouts; low volatility means more frequent but smaller ones. Volatility does not change a game's RTP, and it does not change the house edge. It changes the shape of a session, not the long-run rate of loss.
| Bet | Payout | Coverage | Character |
|---|---|---|---|
| Straight-up | 35 to 1 | One number | High volatility, rare hits |
| Split | 17 to 1 | Two adjacent numbers | High volatility |
| Street | 11 to 1 | Three numbers in a row | High volatility |
| Corner | 8 to 1 | Four numbers | Moderate volatility |
| Six line | 5 to 1 | Six numbers | Moderate volatility |
| Column or dozen | 2 to 1 | Twelve numbers | Lower volatility |
| Red, black, odd, even, high, low | 1 to 1 | Eighteen numbers | Lowest volatility, most frequent hits |
One structural detail matters on the double-zero wheel: the zero and double zero are green, which means they lose on red, black, odd, even, high and low alike. On a European wheel, some tables apply a rule that returns part of an even-money bet when the ball lands in zero. That rule is not standard on North American tables. Where it exists, it changes the effective edge on even-money bets only, and its presence or absence is printed in the table rules.
Procedural Mistakes New Players Make
The most common mistake is buying in with regular casino chips and then trying to bet them on the roulette layout. Roulette tables generally require the colour-coded chips issued at the table. A player who sits down with chips from another table will be asked to exchange them, and the dealer cannot always identify whose regular chips are whose once they are on the felt.
The second mistake is touching chips after the dealer has called no more bets. The call is not a suggestion. Once the ball is in motion, any contact with the layout is treated as a serious breach of procedure, and late bets are void. The same applies to leaning over the table or reaching across other players' stacks.
The third mistake is treating the double-zero wheel as equivalent to a single-zero wheel because the payouts look the same. The payouts are the same, which is exactly the problem. A payout table that ignores the extra pocket is a payout table that charges more for every bet. Reading the wheel before sitting down is the cheapest decision available at the table.
Strategy Charts and Rule Sets
Roulette does not have a basic-strategy chart in the blackjack sense, because no decision the player makes after the spin changes the outcome. The only published references are payout tables and the arithmetic that follows from the wheel type. Any claim about the house edge on a roulette bet is only meaningful when it names the wheel: 37 pockets or 38. A number quoted without that detail is incomplete.
For blackjack, by contrast, published basic-strategy charts derive from the specific rule set in use: deck count, dealer stand rules, doubling and splitting rules. The same principle applies across table games. A chart or a strategy guide is only as good as the rule set it assumes. Before relying on any reference, check that it matches the table in front of you.
FAQ
Does the double zero change every bet on the wheel?
It changes nearly every bet, because the two green pockets lose on all the outside even-money bets and on every inside bet that does not include them. A bet placed directly on the zero, the double zero, or a split covering them is the exception, and its payout is calculated the same way as any other straight-up or split bet.
Is a 38-slot wheel always called an American wheel?
The double-zero layout is commonly called American or North American, and the single-zero layout is commonly called European. The names describe the wheel configuration, not a legal status or a location. A double-zero wheel can appear outside North America, and a single-zero wheel can appear inside it. The pocket count is what matters.
Can a player bet on both zeroes at once?
Yes. On a 38-slot wheel the zero and double zero sit adjacent on the felt, so a split bet covering both is a standard wager. It pays 17 to 1, the same as any other split, and it wins only when the ball lands in one of those two green pockets.
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