The pocket count is the first thing to check at the table
You sit down, buy in, and before you place a single chip you should know which wheel you are looking at. A roulette wheel with 37 pockets has the numbers 1 through 36 plus a single green zero. A wheel with 38 pockets has the same 36 numbers plus a zero and a double zero. That one extra pocket is not a cosmetic difference. It changes the arithmetic on every bet you can make, and it is the reason two tables sitting side by side in the same room can offer different odds on what looks like the same game.
The 37-pocket layout is commonly called the European or single-zero wheel. The 38-pocket layout is the American wheel. Both use the same betting surface, the same sequence of a round, and the same basic rules. What differs is the rate at which the house edge works against you, and that difference is built into the wheel itself, not into anything you do as a player.
What the zero does to a bet
Every roulette bet pays as if the zero pockets did not exist. A straight-up bet on a single number pays 35 to 1, which is the correct price for a wheel with 36 pockets. On a 37-pocket wheel, the zero is the pocket that breaks that symmetry. You can bet on red, and the zero is not red. You can bet on odd, and the zero is not odd. You can bet on the first dozen, and the zero belongs to no dozen. The house edge is the gap between the payout and the true odds created by that extra pocket.
On a 37-pocket wheel, a straight-up bet wins on one pocket and loses on 36. The payout of 35 to 1 is one unit short of what a fair game on 37 equally likely outcomes would pay. That shortfall, spread across every bet, is the house edge. On a 38-pocket wheel the same bet loses on 37 pockets, so the shortfall is larger. The arithmetic works the same way for every bet type: the payout table stays fixed while the number of losing pockets changes.
Wheel types compared
| Feature | 37-pocket wheel (single zero) | 38-pocket wheel (double zero) |
|---|---|---|
| Numbered pockets | 1 through 36 | 1 through 36 |
| Green pockets | One (zero) | Two (zero and double zero) |
| Losing pockets on a straight-up bet | 36 | 37 |
| Effect on the house edge | Lower on equivalent bets | Higher on equivalent bets |
| Common name | European or single-zero | American |
This table is the whole story in miniature. The betting layout, the payouts, and the sequence of play are the same. The wheel itself is the rule that differs.
The sequence of a round
A round moves through a fixed sequence, and understanding it prevents most of the procedural confusion new players run into. First, the dealer or croupier closes betting for the previous spin and settles it: losing bets are cleared, winning bets are paid. Then betting opens for the next spin. You place chips on the layout, either on a single number, a group of numbers, or one of the outside sections. The dealer spins the wheel in one direction and sends the ball travelling the opposite way around the outer track. At some point the dealer calls an end to betting, usually with a phrase or a hand motion. Once that call is made, no chip may be placed or moved. The ball drops into a pocket, the dealer marks the winning number, and settlement begins.
The most common procedural mistake is touching or moving chips after the call. The second is placing a bet that straddles two positions in a way the dealer cannot read. The third is putting chips on the layout while the previous round is still being settled. Each of these slows the table and can lead to a bet being voided or paid differently than you intended. Watch one full round before you play if the table is new to you.
Bet types and where the edge sits
Roulette bets divide into inside bets, which sit on the numbered grid, and outside bets, which sit around its edges. Inside bets cover fewer numbers and pay more. Outside bets cover many numbers and pay less. The house edge on a given wheel is the same for almost every bet on that wheel, but the bets feel very different because their volatility differs. A straight-up bet wins rarely and pays a lot when it does. An even-money bet on red or black wins close to half the time and pays one to one. Neither is a better deal in expected-value terms on the same wheel; they are different distributions of the same edge.
| Bet | Covers | Payout | Feel of the bet |
|---|---|---|---|
| Straight-up | One number | 35 to 1 | Rare wins, large payouts |
| Split | Two adjacent numbers | 17 to 1 | Infrequent wins, large payouts |
| Street | Three numbers in a row | 11 to 1 | Moderately rare wins |
| Corner | Four numbers in a square | 8 to 1 | Moderately rare wins |
| Six line | Six numbers in two rows | 5 to 1 | Fairly frequent wins |
| Dozen or column | Twelve numbers | 2 to 1 | Frequent wins, smaller payouts |
| Red/black, odd/even, high/low | Eighteen numbers | 1 to 1 | Very frequent wins, small payouts |
The payouts are fixed by the layout. What changes between the two wheel types is how many losing pockets each bet carries. On a 37-pocket wheel an even-money bet loses on the zero plus the opposite colour, parity, or half; on a 38-pocket wheel it loses on two green pockets plus the opposite side. The payout does not change, so the edge widens on the American layout.
Why the wheel, not the strategy, decides the edge
No betting pattern changes the number of pockets on the wheel. A progression that doubles your bet after a loss does not remove the zero or the double zero; it changes the pattern of wins and losses you experience, often by concentrating risk into a small number of large bets. The long-run expected loss is still the house edge applied to the total amount you wager. What you control is which wheel you choose, which bets you make, how many spins you play, and how much you stake per spin. Those choices determine how much total money passes across the layout and therefore how much edge the wheel collects from you in expectation. They do not change the edge per unit wagered.
If you want the lower-edge wheel, look at the wheel itself before you buy in. The green pockets are visible from across the table. One green pocket means 37 total. Two means 38. The table layout will also usually carry a printed name or a small diagram of the wheel. When in doubt, ask the dealer which wheel the table uses. That is a normal question and a dealer will answer it without hesitation.
What to check before your first spin
Buy in at the table rather than at the cashier if the table accepts cash buy-ins, and hand the money to the dealer flat on the table rather than passing it hand to hand. The dealer will give you roulette-specific chips if the table uses them, and those chips only have value at that table, so cash them out before you leave. Know the table minimum and maximum, which are posted at the table, and check whether the minimum applies per spin in total or per bet position, because that changes how many outside bets you can cover on a small stack. Watch a round or two before playing. Then place your first bet deliberately, inside or outside, and keep your hands off the layout once the dealer calls the spin.
FAQ
Is a 37-pocket wheel always the better choice?
On equivalent bets, yes in expected-value terms: the single zero gives the house a smaller edge than a double zero on the same bet. But the choice only matters if both wheel types are available where you are playing, and the difference expresses itself over many spins. In a short session, variance dominates and either wheel can produce a win or a loss.
Does the zero count as a losing bet on red or black?
Yes. The zero is green, not red or black, so an even-money bet on either colour loses when the ball lands in zero. The same applies to odd/even and high/low bets. Some tables offer a rule that returns part of an even-money stake when zero lands, but that is a specific table rule you should confirm before relying on it.
How do I know which wheel a table uses before I sit down?
Look at the wheel. A single-zero wheel has one green pocket; a double-zero wheel has two, usually labelled with a single zero and a double zero. The printed layout at the table often names the wheel type as well. If you cannot tell, ask the dealer directly. It is a routine question and takes one second to answer.
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This article is general information about how these mechanics work. It is not legal advice and not a recommendation to gamble or to use any particular operator. Availability and legality differ by jurisdiction — check the rules that apply where you are.