Alexandria Dial
Sun DiscHave 500 practice points
Your practice points ran out. Here are 500 more, once, at no cost. Points are a scorekeeping device and carry no value of any kind.
Stratosphynx runs free simulations of online casino games. Every board follows the real rules and the real odds of the format it simulates, and is played with practice points that have no cash value. There is no real money anywhere on this site, nothing to deposit, nothing to withdraw and nothing to win.
How to play
- Set your entry. Every selection you place costs that amount.
- Pick a selection type first: single number, two neighbours, a row of three, a block of four, or six numbers. Then tap a number on the layout and the selection covers the numbers highlighted for you.
- Below the numbers sit the outside selections: three columns of twelve, three dozens, 1 to 18, 19 to 36, odd, even, and the two colour groups.
- Press release. The ring turns and the ball settles in one pocket. Every selection is settled against the published odds: 35 to 1 on a single number, 17 to 1 on two, 11 to 1 on three, 8 to 1 on four, 5 to 1 on six, 2 to 1 on a column or a dozen, and 1 to 1 on the even-money selections.
- The zero pockets belong to no colour group, no dozen and no column. They are the only reason the long-run return is below even, and the guide below prints exactly how much.
The rules
Choose a whole sector by its number, choose one of the two colour bands, or choose odd against even. Set your entry, place as many selections as you like on the same round, and release the pointer. Every selection is settled independently once the pointer stops, and the round total is the sum of all of them.
If this is your first board
Start with a colour band. It resolves roughly half the time, so you see a lot of rounds quickly and get a feel for how streaks look. A run of six identical results in a row is not evidence that the board is due to switch: the pointer has no memory, and the next release is exactly as likely to repeat as it was the first time.
Pay table
Every figure below is computed from this board's own settings, not typed in by hand.
| Selection | Covers | Odds | Probability | About once in | Long-run return |
|---|---|---|---|---|---|
| Single number | 1 / 37 | 35:1 | 2.70% | 37.0 | 97.30% |
| Two neighbours | 2 / 37 | 17:1 | 5.41% | 18.5 | 97.30% |
| Row of three | 3 / 37 | 11:1 | 8.11% | 12.3 | 97.30% |
| Block of four | 4 / 37 | 8:1 | 10.81% | 9.3 | 97.30% |
| Six numbers | 6 / 37 | 5:1 | 16.22% | 6.2 | 97.30% |
| Column of twelve | 12 / 37 | 2:1 | 32.43% | 3.1 | 97.30% |
| Dozen | 12 / 37 | 2:1 | 32.43% | 3.1 | 97.30% |
| 1 to 18 | 18 / 37 | 1:1 | 48.65% | 2.1 | 97.30% |
| 19 to 36 | 18 / 37 | 1:1 | 48.65% | 2.1 | 97.30% |
| 18 / 37 | 1:1 | 48.65% | 2.1 | 97.30% | |
| 18 / 37 | 1:1 | 48.65% | 2.1 | 97.30% | |
| 18 / 37 | 1:1 | 48.65% | 2.1 | 97.30% | |
| 18 / 37 | 1:1 | 48.65% | 2.1 | 97.30% |
The formula
a selection covering c numbers: probability = c ÷ 37
return = (c ÷ 37) × (odds + 1) = 97.30% for every selection on the layout
Board margin = zeros ÷ pockets = 1 ÷ 37 = 2.70%
The maths behind it
With N equal sectors, one named sector comes up with probability 1/N. This board pays a named sector at a multiple slightly below N, and pays a colour band or an odd/even call at slightly below double. That gap is deliberate and it is published: it is what keeps a long session drifting downward instead of staying flat, and it is the single most useful number to understand about any board of this shape. Nothing here is worth money, so the drift costs you nothing but it teaches the shape of the curve exactly.
Where it comes from
Pointer-and-sector devices are one of the oldest randomising tools people built. A ring divided into equal parts and a pointer released with enough force to forget where it started gives a result nobody can steer. Mathematicians took an interest early precisely because the device is so easy to describe: if the sectors are equal and the release is genuinely uncontrolled, every sector is equally likely, and that is a rare thing to be able to say with confidence.
If this is your first board
Start with a colour band. It resolves roughly half the time, so you see a lot of rounds quickly and get a feel for how streaks look. A run of six identical results in a row is not evidence that the board is due to switch: the pointer has no memory, and the next release is exactly as likely to repeat as it was the first time.