I Love Casinos: Game

Roulette is a casino and gambling game named after a French word for 'little wheel'. In the game, players may wager on either a number, a range of numbers, the colors red or black, or whether the number is odd or even. Players may continue to place bets until the dealer announces, 'No more bets'.

To determine the winning number and color, a croupier spins a wheel in one direction, then spins a ball in the opposite direction around a tilted circular track running around the circumference of the wheel. The ball eventually loses momentum and falls on to the wheel and into one of 37 (in European roulette) or 38 (in American roulette) colored and numbered pockets on the wheel.

Histroy

For a long time the historians considered the French mathematician Blaise Pascal to be the inventor of roulette in around 1655. Some thought that the French Dominican monks came up with the idea of roulette in the end of 17th century to have an entertainment inside their monasteries. However the facts are that the similar in structure games using the spinning wheel had been played at least a century before French roulette became popular game in Paris at the end of French Revolution (1789-1799). Those games were the Italian game of Hoca and the English game of E-O ('Even' and 'Odd').

House Egde

In the early frontier gambling saloons, the house would set the odds on roulette tables at 27 for 1. This meant that on a $1 bet you would get $27 and the house would keep your initial dollar. Today most casino odds are set by law, and they have to be either 34 to 1 or 35 to 1. This means that the house pays you $34 or $35 and you get to keep your original $1 bet.

The house average or house edge (also called the expected value) is the amount the player loses relative to any bet made, on average. If a player bets on a single number in the American game there is a probability of 1/38 that the player wins 35 times the bet, and a 37/38 chance that the player loses their bet. The expected value is:

-1×37/38 + 35×1/38 = -0.0526 (5.26% house edge)
For European roulette, a single number wins 1/37 and loses 36/37:

-1×36/37 + 35×1/37 = -0.0270 (2.70% house edge)
The presence of the green squares on the roulette wheel and on the table are technically the only house edge. Outside bets will always lose when a single or double zero come up. However, the house also has an edge on inside bets because the pay outs are always set at 35 to 1 when you mathematically have a 37 to 1 chance at winning a straight bet on a single number. To demonstrate the house edge on inside bets, imagine placing straight $1 wagers on all inside numbers on a roulette table (including 0 and 00) to assure a win. You would only get back 36 times your original bet having spent $38. The only exception are the five numbers bet where the house edge is considerably higher (7.89% on an American wheel), and the 'even money' bets in some European games where the house edge is halved because only half the stake is lost when a zero comes up.