Roulette is the best-known symbol of casino. Roulette is so popular because of its luxury,passion and simple rules. The world 'roulette' means 'a small wheel' in French. It was Blaise Pascal who introduced the primitive version of this game in the 17th century. The single zero Roulette was introduced in 1842 by Frenchmen Francois and Louis Blank. In the 19th century casino gambling was forbidden in France, that's why the game wasn't so well-known in France, but it was very popular in Hamburg and Germany. Later Francois and his son Camille were responsible for bringing the game of Roulette back to southern France for the Prince of Monaco, Charles III. The game of Roulette was brought to the USA at the beginning of the 19th century. Some additional features were deleted and the game got a double zero back. The game of Roulette attracted a lot of American gamblers.

Jagger’s Wheel.
Of course there always exists a chance that the wheel is not balanced well. That’s why there are unfair gamblers who use it if they notice that the wheel is unbalanced. But nowadays even if you try hard you will never find such a wheel. Casinos, too, have heard the story of Joseph Jaggers and are constantly monitoring their wheels. The wheel is checked several times before it is open to public. In the case of an unbalanced wheel they recalibrate it at once.
2. Another myth is that as more spins occur, players have a better opportunity of hitting a number that has not been hit yet.
It is not so. The probability to hit a number every spin is the same 1 out of 38. If the ball hasn’t landed in this very number for a long period of time it doesn’t mean that it is more likely to do it in a short while. Roulette is a pure game of chance. With every spin the chances of hitting any number are 38:1.

A well-known betting system in roulette is the Martingale system. It varies greatly. You should follow such principle: if you win, then pocket your bet. But when you lose, you double the size of your previous bet.If you win that will guarantee you get back your previous loss and one more unit.And so on.
The Martingale System works great only in case you have an infinite bankroll and no betting limits.
The d'Alembert system is also rather popular. This system assumes that after a win, a player is less likely to win again.So after a win, you subtract a chip from your bet. The d'Alembert system also assumes that you are less likely to lose after a losing spin, so in that case, you add a chip to your bet. The fact that the roulette wheel has no memory and each spin is an independent trial with exactly the same odds of a win or loss is the previous spin is a weak point of the system.