Most crypto and skin-trading sites offer a simplified roulette with a short wheel of coloured pockets instead of the classic 37 numbers. To find its house edge, you only need two things from the game's rules: how many pockets of each colour the wheel has, and what each colour pays. Multiply chance by payout, and the gap to 100% is the edge.
This guide shows the method, works through a typical fictional 15-pocket wheel, and compares several layouts so you can check any variant yourself.
How colour wheels differ from classic roulette
Classic roulette has 36 numbered pockets plus one or more zeros, and dozens of bet types. Colour wheels strip that down:
- A small number of pockets, often 15, but sometimes 21, 25 or 54.
- Usually just three or four bets: one per colour, sometimes plus a bonus pocket.
- Payouts quoted as a multiplier of your stake (2x, 14x), not as classic odds (1:1, 13:1).
That last point matters. A "2x" payout returns your stake plus the same again, which is the same as classic even money (1:1). A "14x" payout is 13:1 in classic terms. Mixing up the two formats is the most common reason people get the edge wrong.
The method in three steps
- Win chance = pockets of that colour ÷ total pockets.
- Return to player (RTP) = win chance × total payout multiplier (stake included).
- House edge = 100% − RTP.
Because the result is a share of the stake, it doesn't matter whether you bet 1 unit or 1,000.
Worked example: a fictional 15-pocket wheel
Take a fictional wheel with 7 red pockets, 7 black pockets and 1 green pocket. Red and black pay 2x; green pays 14x.
| Bet | Pockets | Win chance | Payout (x stake) | RTP | House edge |
|---|---|---|---|---|---|
| Red | 7 | 46.67% | 2x | 93.33% | 6.67% |
| Black | 7 | 46.67% | 2x | 93.33% | 6.67% |
| Green | 1 | 6.67% | 14x | 93.33% | 6.67% |
The working for red: 7/15 × 2 = 14/15 = 93.33%, so the edge is 1/15 = 6.67%. For green: 1/15 × 14 = 14/15 = 93.33% again. Every bet on this wheel costs the same 6.67% on average.
Compare that with classic single-zero roulette at 2.70% (see our odds and house edge guide). The 15-pocket layout costs about two and a half times as much per unit staked. Over 100 units staked, that's an expected cost of about 6.67 units rather than 2.70.
Comparing other fictional layouts
The same method works for any wheel. Here are several fictional layouts, recomputed with a script. Payouts include the stake.
| Fictional wheel | Layout | Main colours pay | Main colour edge | Special pocket pays | Special pocket edge |
|---|---|---|---|---|---|
| A | 7 red / 7 black / 1 green (15) | 2x | 6.67% | 14x | 6.67% |
| B | 10 red / 10 black / 1 green (21) | 2x | 4.76% | 20x | 4.76% |
| C | 18 red / 18 black / 1 bonus (37) | 2x | 2.70% | 36x | 2.70% |
| D | 26 red / 26 black / 2 gold (54) | 2x | 3.70% | 25x | 7.41% |
Two things stand out:
- More pockets of the main colours usually means a lower edge on those bets, because the single "house" pocket is a smaller share of the wheel. Wheel C behaves just like classic single-zero roulette.
- Special pockets can be priced differently from the colours. On fictional wheel D, the gold bet costs twice as much as red or black. Check each bet separately; don't assume one edge applies to the whole game.
The "overdue green" myth
Colour wheels usually show a history strip of recent results. It's tempting to read it as a forecast: green hasn't hit in 40 spins, so it must be close.
It isn't. Each spin is unaffected by the previous ones, so the chance of green on the next spin is always 1 in 15 on wheel A. Long gaps are also more common than they feel:
| Spins in a row | Chance of no green (fictional 15-pocket wheel) |
|---|---|
| 15 | 35.5% |
| 30 | 12.6% |
| 45 | 4.5% |
A run of 30 spins without green happens about one time in eight. On a busy site that runs spins every few seconds, you'll see gaps of that length all the time. They aren't signals, and betting more because of them only increases how much you stake, which increases your expected cost.
Skin-site and crypto-site details to check
Colour wheels on crypto and skin-trading sites often come with extra rules that affect the maths or your money:
- Currency conversion. Some sites use a house currency or coin balance. The edge applies on top of any spread you pay converting in and out.
- Item values. Where skins or items are used as a balance, the site's valuation may differ from what you could get elsewhere. That gap is a cost too.
- Bonus pockets and jackpots. Extra features can change the edge on specific bets. Recalculate with the published payouts.
- Provably fair mapping. Many colour wheels let you verify each spin with seeds and hashes. Our guide to provably fair roulette shows how a hash becomes a pocket.
Checklist: working out a variant's edge
- Find the pocket count for each colour in the game's rules or help panel.
- Confirm whether payouts are quoted as multipliers (stake included) or classic odds.
- Calculate RTP for each bet separately: chance × multiplier.
- Subtract from 100% to get the edge.
- Compare with 2.70% for single-zero classic roulette.
- Ignore history strips when deciding what to bet.
- Set a budget first; the edge decides the average cost, not your luck in one session.
No layout, colour choice or pattern on the history strip turns a negative-edge wheel into a positive one. Roulette in every form is gambling, and the expected result of playing is a loss.
Questions readers ask
What is a 15-slot roulette wheel?
A simplified wheel used on many crypto and skin-trading sites, usually with 7 red, 7 black and 1 green pocket. Red and black typically pay 2x the stake and green pays 14x.
Is the green bet on a 14x wheel better value than red or black?
Not on the typical layout. On a fictional 7/7/1 wheel with 2x and 14x payouts, both bets return 93.33% of stakes on average, so both carry a 6.67% edge. Green just swings more.
Is a green pocket overdue after a long gap?
No. Each spin is unaffected by previous spins. On a 15-pocket wheel the chance of green on the next spin is 1 in 15 whether the last green was 3 spins ago or 60.
How do I calculate the edge of any wheel?
Multiply each bet's win chance by its total payout (stake included) to get its return to player, then subtract from 100%. The pay table and the pocket count are all you need.