The spinning roulette wheel is perhaps the most recognizable symbol of casino gambling worldwide. While the fundamental idea —picking the winning number— never changes, not every roulette game offer the exact same odds. The casino world features two main versions that dominate the casino floors: the US version and the European wheel. Learning the mathematical distinctions between these wheels is incredibly important for any player wanting to maximize their chances of winning.
The Number of Pockets: The One Massive Difference
The most significant difference between the two games lies in the layout of the wheel itself. A traditional European Roulette wheel has exactly thirty-seven slots: numbers one to thirty-six, plus one 0. On the other hand, the American Roulette wheel contains 38 spaces. It has the standard 36 numbers, the single green zero (0), and an extra green slot: the 00. This one additional space may look trivial to a casual tourist, but in reality, it alters the odds massively.
How the Double Zero on the House Edge
In roulette, the winning odds paid are strictly designed as if the zero did not exist. For instance, a winning straight-up bet returns 35 times your bet, no matter the wheel type. Because the European wheel has 37 total slots, the casino's built-in mathematical advantage is exactly 2.70 percent. But, because the double zero wheel adds that second green slot without increasing the payouts, the casino's advantage skyrockets to a massive 5.26%.

Always look for the single zero if both are available. There is absolutely no reason to play with a double zero. The 'Five Number Bet' is unique to the US wheel and is the absolute worst bet, giving the house a 7.89% advantage. Some European tables offer the 'En Prison' or 'La Partage' rules, which reduces the casino margin on red/black wagers down to an incredible 1.35%.

A Quick Comparison: Both Wheels Compared
To make the difference completely clear, take a look at this simple chart. It shows the exact reason why pros always prefer the French or Euro games.

CharacteristicEuropean RouletteUS Layout Spaces on Wheel3738 Zero Slots1Double Zero Casino AdvantageLow at 2.70%High at 5.26% Best Odds1.35% on even money betsAlways 5.26%

In conclusion, the extra 00 pocket is nothing more than a casino trick to double their profits from the average gambler. If you are playing at a lavish casino in Las Vegas or spinning the wheel at an online casino from your smartphone, your first goal should be locating a single zero game. Skipping the 00 wheel is the simplest method to instantly double your long-term returns.