European Roulette and American Roulette
European roulette, also known as single zero roulette, is the original game as it was played in France before moving to the new world. American roulette is the adaptation of the game for North American markets, and plays off of a wheel with both a zero pocket, and a double zero pocket.
The addition of a second green ‘zero’ pocket on American roulette has a direct effect on the house edge for the game. On our mathematics of roulette page we discussed the expectation formula for a number of roulette bets, in the context of an American board. The very same formula can be used for European roulette, and you will find the house edge is also a consistent number across bets, but the number is much more player-friendly.
An American roulette wheel has 38 numbers in total, two being green pockets that cannot win on outside bets. The expectancy of this game is -5.25%, found by the formula:
E = [1/38 X 35] + [37/38 X -1]
= [0.921] + [-0.9736]
= -0.526 or -5.26%
A European roulette wheel has 37 numbers in total, with one green pocket that cannot win on outside bets. The expectancy of this game is -2.70%, found by the formula:
E = [1/37 X 35] + [36/37 X -1]
= [0.945945] + [-0.972972]
= -0.027 or -2.70%
So the house edge of European roulette is nearly half that of American roulette. More than that, any gambler will tell you, a house edge of 5.25% is rather unfriendly, but a house edge of 2.70% is very reasonable.
There are a few, small, precious ways to improve on our chances in roulette. These mostly stem from options and rule changes dependent upon the specific rules of the table you’re at. To learn more about these opportunities to improve your chances of winning, read our roulette strategy section.
Online casinos offer European and american roulette and many other great games like online slots