You sit down at what looks like a standard roulette table and place $10 on red. Depending on which variant you’re playing, your expected loss ranges from 27 cents to 53 cents per spin. Same bet, same payout, wildly different mathematics.
Most players don’t realize that roulette variants are not just cosmetic differences. They are different games with significantly different odds. Here’s the mathematical breakdown that determines how fast your money disappears.
The mathematics applies equally to sites like online casino Rooli, which operates under established gambling jurisdiction oversight with over 3,000 titles from providers including Atmosferus and BGaming. Their structure follows standard industry patterns—welcome packages up to $4,000 plus 475 spins, cryptocurrency options reaching 12 BTC—but the underlying house edge calculations remain identical regardless of promotional wrapping.
American Roulette: The House Edge King
American roulette features 38 pockets: numbers 1-36, plus 0 and 00. This double-zero setup creates the worst odds for players among major roulette variants.
The Mathematics:
- Red/black bets: 18 winning numbers out of 38 total
- Probability of winning: 18/38 = 47.37%
- House edge: 5.26% on all bets (except the five-number bet at 7.89%)
Expected Loss Calculation: On a $10 red bet, you lose $10 when any of 20 numbers hit (18 black + 0 + 00) and win $10 when 18 red numbers hit. Expected loss = ($10 × 20/38) – ($10 × 18/38) = $5.26 – $4.74 = $0.53 per spin
Why It’s Popular: American roulette dominates US casinos because the extra house edge generates significantly more revenue. The 00 pocket alone increases casino profits by roughly 35% compared to single-zero games.
European Roulette: The Standard Bearer
European roulette eliminates the 00, leaving 37 pockets: numbers 1-36 plus a single 0. This simple change dramatically improves your odds.
The Mathematics:
- Red/black bets: 18 winning numbers out of 37 total
- Winning probability: 18/37 = 48.65%
- House advantage: 2.70% across all bets
Many players turn to their favorite bitcoin casinos, believing cryptocurrency somehow improves their odds, but the 2.70% house edge applies universally across all payment methods.
Expected Loss Calculation: On a $10 red bet, you lose $10 when 19 numbers hit (18 black + 0) and win $10 when 18 red numbers hit. Expected loss = ($10 × 19/37) – ($10 × 18/37) = $5.14 – $4.86 = $0.27 per spin
Availability: Common in European casinos and increasingly available online. Some US casinos offer European roulette, but often with higher minimum bets to maintain revenue.
The same mathematical analysis that reveals roulette odds also applies when evaluating lucky 88 slot machine tips and their statistical validity.
French Roulette: The Player’s Best Friend
French roulette employs the identical 37-number wheel found in European roulette but incorporates additional rules that cut the house advantage on even-money wagers.
La Partage Rule: When 0 appears, even-money bets (red/black, odd/even, high/low) forfeit only half their amount rather than the complete stake.
En Prison Rule (Alternative): When 0 appears, even-money bets get “locked” (imprisoned) for the following spin. Should the locked bet succeed on the subsequent spin, it returns without profits. Should it fail, the house claims it.
The Mathematics with La Partage:
- Winning probability: 18/37 = 48.65%
- Half-loss probability (when 0 appears): 1/37 = 2.70%
- Full-loss probability: 18/37 = 48.65%
- House advantage on even-money bets: 1.35%
Expected Loss Calculation: On a $10 red bet with La Partage: Expected loss = ($10 × 18/37) + ($5 × 1/37) – ($10 × 18/37) = $0.14 per spin
Why It’s Scarce: French roulette delivers the smallest house advantage, reducing casino profitability. Most venues favor the superior margins of American and European roulette versions.
Finding the Best Games Online
European Roulette: Available at most online gaming sites. Seek games marked “European” instead of generic “Roulette.”
French Roulette: Not as widespread but found at reputable gaming sites. Hunt for “French Roulette” or games highlighting “La Partage.”
American Roulette: Unfortunately common online, especially at US-facing casinos. Always check the wheel layout before playing.
The Verdict
For even-money bets, French roulette’s 1.35% house edge means you lose roughly $1.35 per $100 wagered long-term. American roulette’s 5.26% house edge costs you $5.26 per $100. Choose accordingly.
Mathematics doesn’t lie: French roulette with La Partage offers the best odds, European roulette provides good value, and American roulette should be avoided unless it’s your only option.
The Bottom Line: The roulette variant you choose affects your expected losses more than any betting strategy or system ever will. Pick the right wheel before worrying about picking the right numbers.
