American Roulette Wheel
As you already know there are two types of roulette wheels. The difference between European and American roulette wheels is the number of slots for ball landing. European roulette contains the slots from 1 to 36 and one zero (0) slot, while American roulette except mentioned ones has double zero (00) slot. All the numbers on American roulette wheel are arranged in pairs, every member of which is opposite to another. The numbers on European roulette are set in a random order.
The fact that American roulette contains one additional slot (compared to European roulette) influences the house edge. Thus at American roulette the player's winning odds are much lower. Some players insist that this difference is not so significant but in fact it works in the long run. If mathematically calculated the house edge at American roulette is 5.26%.
The sequence of numbers at American roulette is as follows: 0-28-9-26-30-11-7-20-32-17-5-22-34-15-3-24-36-13-1-00-27-10-25-29-12-8-19-31-18-6-21-33-16-4-23-35-14-2
European Roulette Wheel
European roulette wheel contains total 37 numbers, from 0 to 36, and doesn't have double zero (00) slot while American wheel does. This is the most important difference between two wheels that reduces the house edge to 2.70%.
As it has been already mentioned European roulette wheel is more symmetrical as the numbers are arranged in pairs the members of which are opposite to each other. But American wheel is more practical as the first and last 18 numbers alternate with each other and odd/even, red/black numbers are placed close to each other.
The sequence of numbers at European roulette is as follows: 0-32-15-19-4-21-2-25-17-34-6-27-13-36-11-30-8-23-10-5-24-16-33-1-20-14-31-9-22-18-29-7-28-12-35-3-26
Moreover, there is an additional option at European roulette called "en prison". This option reduces much the house edge and thus increases the players' winning odds. En prison rule is applicable for outside bets. In this case if the ball lands on the 0 the bet is left for the next spin and the player doesn't lose immediately like at American prison. If the bet wins in the next spin the player gets back the wagered money (with no winnings) and if the bet loses the player gets nothing.