A reminder before the details
Roulette is a game of chance with a built-in house edge. No strategy, system, pattern or timing changes the odds in the player’s favor over time, and most players lose money over time. Nobody should gamble money they cannot afford to lose. Learning the bet types explains what each chip does; it does not make any bet a better way to win.
Two families of bets
The layout splits bets into two families by where the chips go. Inside bets are placed on or between the numbers in the central grid. Outside bets are placed in the boxes at the edge of the grid. The labels are about position on the cloth, not about quality or risk, though in practice the inside bets tend to be the long shots and the outside bets the frequent ones.
The figures below assume a single-zero wheel with 37 pockets. Each pocket is equally likely, so the chance of a bet winning is simply the number of winning pockets divided by 37.
Inside bets
Straight up. A chip on one number. It wins on 1 pocket, a chance of 1 in 37 (about 2.7 percent), and pays 35 to 1.
Split. A chip on the line between two adjacent numbers on the grid. It wins on either of 2 pockets, 2 in 37 (about 5.4 percent), and pays 17 to 1.
Street. A chip at the edge of a row of three numbers. It wins on 3 pockets, 3 in 37 (about 8.1 percent), and pays 11 to 1.
Corner. A chip at the point where four numbers meet. It wins on 4 pockets, 4 in 37 (about 10.8 percent), and pays 8 to 1.
Six line. A chip at the edge between two neighboring rows, covering six numbers. It wins on 6 pockets, 6 in 37 (about 16.2 percent), and pays 5 to 1.
There are a few additional inside combinations, such as bets that include the zero. Their names and availability vary between tables, and they follow the same rule that payouts are tied to the number of pockets covered. Placing several inside chips at once simply combines these bets.
Outside bets
Dozens. The first dozen (1 to 12), second dozen (13 to 24) or third dozen (25 to 36). Each wins on 12 pockets, 12 in 37 (about 32.4 percent), and pays 2 to 1.
Columns. The three vertical lines of the grid, each with twelve numbers. Each wins on 12 pockets and pays 2 to 1, like the dozens, but the numbers covered are spread across the layout instead of sitting together.
Even-money bets. Red or black, odd or even, low (1 to 18) or high (19 to 36). Each wins on 18 pockets, 18 in 37 (about 48.6 percent), and pays 1 to 1. The zero is not red, black, odd, even, low or high, so it loses all of these.
The whole picture in one table
| Bet | Winning pockets | Chance on 37 pockets | Pays |
|---|---|---|---|
| Straight up | 1 | 1/37 (about 2.7%) | 35 to 1 |
| Split | 2 | 2/37 (about 5.4%) | 17 to 1 |
| Street | 3 | 3/37 (about 8.1%) | 11 to 1 |
| Corner | 4 | 4/37 (about 10.8%) | 8 to 1 |
| Six line | 6 | 6/37 (about 16.2%) | 5 to 1 |
| Dozen or column | 12 | 12/37 (about 32.4%) | 2 to 1 |
| Red/black, odd/even, low/high | 18 | 18/37 (about 48.6%) | 1 to 1 |
Why a bigger payout goes with a smaller chance
The payouts are built so that covering more pockets pays less per win. As the number of winning pockets rises from 1 to 18, the payout falls from 35 to 1 down to 1 to 1. In every row of the table, the payout plus one, multiplied by the pockets covered, equals 36 (for example, (8 + 1) × 4 = 36). That is what a fair 36-pocket wheel would pay, which is the idea behind payout ratios. The catch is that the real wheel has 37 pockets, so the bets are not quite fair.
A hypothetical check with a stake of 1 unit. A straight bet wins 35 on 1 pocket and loses 1 on 36 pockets: 35 − 36 = −1 over 37 pockets, an average of −1/37 per spin. A corner wins 8 on 4 pockets and loses 1 on 33: 32 − 33 = −1, again −1/37. A red bet wins 1 on 18 pockets and loses 1 on 19: 18 − 19 = −1, again −1/37. The result is the same each time: the edge does not depend on which standard bet is chosen.
What actually differs between the groups
If the average cost is the same, the groups differ in how results are distributed. A straight-up bet usually loses and occasionally pays a large amount, so a session of such bets can swing sharply either way. An even-money bet wins almost half the time and swings in smaller steps. The difference is in statistical variance, not in expected cost, and a smoother ride does not mean a better bet. It also does not mean the player can recover anything: the average result of every standard bet is a small loss per unit staked.
Covering many numbers at once does not reduce the cost either. If the chips cover most of the layout, results tend to be close to a small loss each spin, but the amount staked is larger, so the total expected loss is larger too. This is also why mixing bets does not work as hedging bets: opposite or overlapping bets still sum to the same edge.
Some practical points
- Minimum and maximum bets are often posted separately for inside and outside bets, so a table may allow smaller stakes on one group than the other.
- Chip placement matters. A chip that sits across a line is a different bet from a chip placed in the middle of a number, so the dealer may ask for clarification.
- A hypothetical player who stakes 5 units each on 4 different straight numbers is staking 20 units a spin and has 4 of 37 pockets winning, the same coverage as a corner but a different payout structure, with the same average edge.
Decide how much you can afford to spend on entertainment before playing, and treat any win as a surprise rather than an outcome you can plan for.