Roullete, or roulette as it is more commonly known, is one of the oldest and most popular casino games in the world. The game is played on a circular disk or board that is slightly convex with a red and black color scheme, and has thirty-six compartments, called frets by roulette croupiers, numbered nonconsecutively from 1 to 36. On European-style wheels, a green compartment carries the number 0.

A roulette wheel is perfectly balanced and spins in an almost frictionless manner. The game was first mentioned in a written document in 1716, and it is believed to be based on earlier casino games, including hoca and portique.

In addition to the single-number bets, roulette offers a host of other betting options, with the odds and payouts varying based on the type of bet made. A quick search on the Internet will reveal many (possibly millions) of systems for playing roulette, some simple and some supposedly complex. All have the common denominator that they can’t beat the maths. A better way to approach the game is to focus on symmetries in the numbers and the wheel.