Counting the Pockets Before You Place a Chip
Most players sit down at a roulette table with a vague sense that red and black alternate around the wheel, but they have never counted the pockets. The count matters because every bet on the layout is priced against the full set of pockets, including the ones that are neither red nor black. A player who knows there are 37 pockets on one wheel and 38 on another can see immediately why two tables with identical felt layouts do not offer identical odds.
A standard European roulette wheel carries 37 pockets. Of these, 18 are red, 18 are black, and a single pocket is green: the zero. An American wheel carries 38 pockets. It has the same 18 red and 18 black numbers, but adds a second green pocket, the double zero. The green pockets are not a decoration. They are the mechanism by which the house edge is built into the wheel, and every wager on red, black, odd, even, high or low is exposed to them.
The Color Layout on the Two Main Wheel Types
Roulette wheels are not simply painted in alternating colors around the rim. The sequence of numbers is fixed for each wheel type, and the colors follow that sequence. On a European wheel the single zero sits between 32 red and 26 black. On an American wheel the zeros sit opposite each other, with the double zero between 2 black and 14 red, and the single zero between 2 black and 28 black in most common layouts. The number sequence is not the same on the two wheel types, so a player moving between tables should not assume the color pattern they memorized on one wheel transfers to the other.
The table below compares the two wheel types by pocket count and color distribution.
| Wheel type | Total pockets | Red pockets | Black pockets | Green pockets |
|---|---|---|---|---|
| European (single zero) | 37 | 18 | 18 | 1 |
| American (single and double zero) | 38 | 18 | 18 | 2 |
The extra green pocket on the American layout does not change how many red or black numbers exist. It changes the probability that a red or black bet wins, because the denominator of every calculation grows by one while the number of winning pockets stays fixed.
Why the Green Pockets Change the Price of a Color Bet
A bet on red wins when the ball lands in any red pocket. On a European wheel, 18 of the 37 pockets are red, so the probability of winning a red bet on any given spin is 18 in 37. The house edge is the difference between the true odds of winning and the payout the table offers. A winning red bet pays even money, or 1 to 1, but the presence of the zero means the bet does not win 18 times out of 36; it wins 18 times out of 37. The missing outcome is the green zero, which pays neither red nor black on most tables and is collected by the house.
On an American wheel the same red bet wins 18 times out of 38. The double zero adds a second outcome that defeats both red and black, odd and even, and high and low bets. This is why the American layout carries a higher house edge on those outside bets than the European layout. The color count is identical; the zero count is not.
Some tables offer a rule that softens this effect on even-money bets, such as returning half the stake or holding it for the next spin when the ball lands in zero. That rule is specific to certain tables and jurisdictions, and it changes the effective edge on red, black, odd, even, high and low. A player should read the posted table rules before assuming the zero behaves the same way everywhere.
Red and Black Numbers in Full
The red numbers on a standard roulette wheel are the same set on both European and American layouts. They are 1, 3, 5, 7, 9, 12, 14, 16, 18, 19, 21, 23, 25, 27, 30, 32, 34 and 36. The black numbers are 2, 4, 6, 8, 10, 11, 13, 15, 17, 20, 22, 24, 26, 28, 29, 31, 33 and 35. The zero and double zero are green and carry no color designation for the purposes of red or black bets.
A common misreading is that the zero is somehow neutral and therefore harmless. It is not neutral. On a color bet, the zero is a losing outcome for both red and black. On an American wheel, the two green pockets together represent a larger share of the wheel than any single number, and they are the reason the house edge on outside bets is nearly twice as high as on a European wheel under standard rules.
What the Color Count Does and Does Not Tell You
Knowing that there are 18 red and 18 black pockets tells a player the probability of a color bet winning on a single spin, but it does not tell them what will happen in the next ten spins. Each spin is an independent event under a properly functioning random number generator or physical wheel. A run of five reds does not make black more likely on the sixth spin, because the wheel has no memory and the pocket count has not changed. The only thing that changes the probability of a color bet is the wheel type, because the wheel type changes the number of green pockets.
The color count also does not tell a player which color to bet. Red and black carry the same probability and the same payout on a given wheel, so neither color offers a better expected return than the other. The choice between them is a matter of preference, not mathematics. The mathematical difference lies between wheel types and between bet types, not between colors.
Reading the Table Before You Buy In
Before placing any wager, a player should confirm which wheel type is in use. The wheel itself is the most reliable indicator: a single green zero means a European layout, while a wheel with both a zero and a double zero is an American layout. The felt layout will also show the zeros on the betting grid, and the posted minimum and maximum stakes will be printed nearby. Some venues run both wheel types in the same room, so the wheel in front of the player is the only one that matters.
The table also carries the payout schedule. Red and black pay even money on both wheel types, but the presence of one or two green pockets changes the true odds behind that even-money payout. A player who understands the color count can read the payout schedule and see exactly how the house edge is constructed for each bet on the layout.
FAQ
Are there always 18 red numbers on a roulette wheel?
Yes, on both standard European and American wheels there are 18 red numbers and 18 black numbers. The difference between wheel types is the number of green zero pockets, not the red or black count.
Does the zero count as red or black?
Neither. The zero and double zero are green pockets that lose on red, black, odd, even, high and low bets unless a specific table rule says otherwise. They are the pockets that create the house edge on those even-money wagers.
Why does the American wheel have worse odds if the colors are the same?
Because the American wheel adds a second green pocket. A red bet still wins on 18 pockets, but now there are 38 total pockets instead of 37, so the bet wins less often while still paying even money. The extra green pocket is the entire difference.
Play responsibly
Gambling should be treated as paid entertainment, never as a way to earn income or recover losses. 1-800-MY-RESET (1-800-697-3738)
18+ or 21+ depending on where you are; follow the minimum age that applies to you.
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.