Sun Disc

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.

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.

Where you meet it today

You meet the same mechanism in classroom probability kits, in television game formats, in fairground stalls, and in the pointer packed with a hundred different board games. Software versions are everywhere too, from the raffle pickers teachers use to the round choosers people launch to settle where to eat.

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.

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.

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.

Every board in this family

Each board has its own guide with its own pay table, its own probabilities and the arithmetic worked through with that board's numbers.

Other families

Glyph Match · Scribe’s Cards · Sand Reveal · Oracle Draw

All games