The Count That Changes the Game
You sit down at a roulette table and the first thing you notice is the wheel itself. Some wheels have one green pocket marked with a zero. Others have two. That single difference changes the arithmetic on every bet you can place, so it is worth knowing before you put chips down.
A European roulette wheel carries 37 pockets: the numbers 0 through 36, with the 0 pocket coloured green and the rest alternating red and black. An American roulette wheel carries 38 pockets: the same 0 through 36, plus a second green pocket marked 00. The extra pocket does not add a new number to bet on in the usual sense; it adds a second outcome that loses for most bets.
The wheel is only half the story. The table layout mirrors the wheel, and the two must match. When you look at the felt, you will see the same numbers arranged in a grid, with the zero or zeros sitting at the top of the layout. A wheel and layout from different variants never appear together at a properly run table.
Why the Extra Pocket Matters
The pocket count is not a cosmetic detail. It sets the baseline for the house edge on nearly every roulette bet. On a European wheel, a straight-up bet on a single number pays 35 to 1, but there are 37 pockets, so the true odds of hitting are 36 to 1 against. The gap between the payout and the true odds is where the house edge lives.
On an American wheel, the same bet still pays 35 to 1, but there are now 38 pockets. The player's chance of hitting a single number shrinks, while the payout stays fixed. The house edge on an American layout is therefore higher than on a European layout for the same bet type. The 00 pocket is the reason.
This relationship holds across the main bet categories, though the exact edge differs from one bet to another. The table below compares the two wheel types and what the pocket count means for a straight-up bet.
| Feature | European wheel | American wheel |
|---|---|---|
| Total pockets | 37 | 38 |
| Zero pockets | 1 (single zero) | 2 (single and double zero) |
| Number range | 0-36 | 0-36 plus 00 |
| Straight-up payout | 35 to 1 | 35 to 1 |
| True odds against a single number | 36 to 1 | 37 to 1 |
| Effect on house edge | Lower baseline | Higher baseline |
The table shows the structural difference without putting a percentage on it. The precise house edge for any given bet depends on the rule set in force at the table, and some European tables apply additional rules that alter certain bets. The wheel type is the starting point, not the whole calculation.
Reading the Wheel Before You Bet
Before you place a chip, confirm which wheel you are at. The green pockets are the giveaway: one green pocket means European, two means American. Some venues also run French roulette, which uses the same 37-pocket wheel as European but adds rules that change what happens when the ball lands in zero on certain outside bets.
The pocket count also affects how you should read the board that displays recent winning numbers. Those displays record outcomes; they do not change the odds of the next spin. A wheel with 38 pockets has no memory of the previous spin, and no number becomes more or less likely because it has or has not appeared recently.
When you sit down, the dealer or the table signage will state the minimum and maximum bets. The wheel type does not change those limits, but it does change the expected rate of loss on every unit you wager. If you have a choice between two tables with the same limits and one has a single zero while the other has a double zero, the single-zero wheel carries a lower house edge on the same bets.
Inside the Round: From Buy-In to Settlement
A roulette round moves through a fixed sequence, and knowing that sequence keeps you from making procedural mistakes. You buy in by placing cash on the table, never into the dealer's hand. The dealer exchanges it for roulette chips, which are colour-coded to you and have no value away from the table. You must cash them in at the same table before you leave.
Once the dealer clears the previous round and the marker is removed from the layout, the betting window opens. You place chips on the layout, either on individual numbers or on the outside areas that cover groups of numbers. The dealer announces when no more bets are accepted, usually as the ball begins to slow. After the ball settles, the dealer marks the winning number, clears losing bets, and pays winners.
Two procedural errors recur among new players. The first is reaching for chips after the dealer has called no more bets. The second is touching chips on the layout after the ball has landed. Both are treated as serious at any table, because the layout is the record of who bet what. Keep your hands clear once the ball is in motion.
Bet Types and Where the Edge Sits
Roulette bets fall into two broad families: inside bets on specific numbers or small groups, and outside bets on larger categories such as red or black, odd or even, or high or low. The payouts differ, and so do the house edges, but on a standard wheel the edge structure is consistent: the more numbers a bet covers, the lower the payout and the lower the variance, while the house edge stays broadly similar across most bets on the same wheel.
The exception on an American wheel is the five-number bet covering 0, 00, 1, 2 and 3. This bet carries a higher house edge than other bets on the same layout, because it pays 6 to 1 while the true odds against it are worse than that payout implies. On a European wheel there is no equivalent five-number bet, because there is no 00.
The table below lays out the main bet types, what they cover, and their payout structure.
| Bet type | What it covers | Payout | Variance profile |
|---|---|---|---|
| Straight-up | One number | 35 to 1 | High variance, rare wins |
| Split | Two adjacent numbers | 17 to 1 | High variance |
| Street | Three numbers in a row | 11 to 1 | High variance |
| Corner | Four numbers in a square | 8 to 1 | Moderate variance |
| Six line | Six numbers in two rows | 5 to 1 | Moderate variance |
| Dozen or column | Twelve numbers | 2 to 1 | Lower variance |
| Red/black, odd/even, high/low | Eighteen numbers | 1 to 1 | Lowest variance |
Variance describes how payouts are distributed over time, not whether a bet is better. A straight-up bet can win more in a single spin than an outside bet, but it loses far more often. The house edge on each bet type is a separate matter from variance, and on the same wheel the edge differences between most bets are smaller than the variance differences.
What the Zero Does to Outside Bets
The zero pockets sit outside the red/black, odd/even and high/low categories. When the ball lands in zero, most outside bets lose outright. This is the structural reason the zero matters so much: it is the outcome that breaks the symmetry of the even-money bets.
Some European tables apply a rule that changes this. Under the en prison or la partage rule, an even-money bet that loses to zero is either held for the next spin or half of it is returned. These rules reduce the house edge on those specific bets, and they exist only on single-zero wheels. An American table does not offer them, because the double zero is already the second losing pocket for outside bets.
If you want to know which rule applies at a given table, look at the felt or ask the dealer. The rule is always posted or stated, and it changes the expected loss on even-money bets specifically.
Wheel Construction and Fairness
The pocket count is fixed by the wheel's design, but the wheel itself is a mechanical device that operators maintain and inspect. Pockets are machined to consistent dimensions, and the wheel is levelled and balanced. A wheel that is out of level or damaged can produce biased results, which is why venues check their wheels regularly.
This does not mean any wheel is predictable from the outside. The ball's deceleration, the rotor speed, and the frets between pockets all introduce enough variation that no player can reliably forecast where the ball will land. The wheel's job is to produce outcomes that are as close to random as a physical device allows, and the house edge is built into the payout structure rather than into any supposed pattern in the wheel.
For online roulette, the wheel is a simulation driven by a random number generator. The same pocket count applies, and the same payout structure governs the bets. The generator determines the outcome; the pocket count and payout table determine the house edge.
Choosing a Table by Pocket Count
When you walk into a venue with multiple roulette tables, the pocket count is the first thing to check after the table limits. A single-zero table with a lower maximum bet may be a better structural choice than a double-zero table with a higher maximum, because the edge on every unit wagered is lower on the single-zero wheel.
That said, the edge difference does not make roulette a winning game. It makes the expected rate of loss slower on one wheel than the other. No bet selection, progression, or pattern changes the built-in edge. The pocket count is a fact you can use to choose between tables, not a strategy for beating the game.
If you are playing online, the game information panel states the wheel type and the rules in force. Read it before you spin. The pocket count is always displayed, and the rule set determines whether any zero-related rules apply to outside bets.
FAQ
Why does an American wheel have more pockets than a European wheel?
The American layout adds a double zero pocket to the standard 0-36 sequence, bringing the total to 38. The double zero originated as an additional house-favourable outcome, and it remains the structural difference between the two wheel types. The extra pocket increases the house edge on every bet that does not specifically include it.
Do the extra pockets change how much a winning bet pays?
The payout for a given bet type is the same on both wheels. A straight-up bet pays 35 to 1 whether the wheel has 37 or 38 pockets. What changes is the probability of winning, because the extra pocket is an additional losing outcome for most bets. The fixed payout combined with the lower win probability is what raises the house edge.
Can I tell which wheel I am at without counting the pockets?
Yes. Look at the green pockets. One green pocket means a single-zero wheel with 37 pockets; two green pockets means a double-zero wheel with 38. The table layout will also show the zero or zeros at the top of the number grid, and the game information panel online states the wheel type explicitly.
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