Roulette is a gambling game in which a small ball is spun around a revolving wheel and when it comes to rest the player makes bets on which red or black numbered compartment the ball will enter. Bets are placed against the house, and players may choose to bet on a single number or various groupings of numbers that pay off at lesser odds if they win. The game developed into its modern form in the late 18th century.
The wheel consists of thirty-six compartments, painted alternately red and black and numbered 1 to 36 in a seemingly random pattern, with one extra green division marked 0 on European wheels (American wheels have two additional green pockets labelled 00). The roulette ball is spun around the perimeter of the wheel while the croupier places a marker or dolly onto the winning number on the table and removes all losing bets.
When a bet is won the player’s chips are moved from the table to the croupier who then pays out the winning bet. If the bet is on a number, its payout is equal to the amount wagered plus the winnings from any other bets that won on the spin.
There are a few symmetries in the roulette wheel that can be exploited by professional gamblers. For example, the high red and low black numbers are clustered together on opposite sides of the zero pocket (these are called ‘Dozens’) while the second dozen (13-24) is scattered. This is where most of the action occurs and can be exploited by a smart player.
A simple search on the internet will return millions of systems for playing (and supposedly winning) roulette, some very easy and others highly complex, some well-described and some not at all. However, it is difficult to find a system that can convert a subfair game like this into one that has a positive edge for the player. This is because the house has a mathematical advantage in almost any situation.