The wheel is not well balanced.
Since Jaggers discovered the unbalanced wheel many casino patrons today are on the look out for the unbalanced wheel in order to make some fast cash. 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 a mistake. The chances of hitting any number is 38:1. Just because the number seven has not hit for hours, does not mean it will hit soon. Remember roulette is a game of chance and the odds are the same for every number with every spin of the wheel.

There are 36 numbers, which are divided among red or black pockets on the Roulette wheel. The pocket is an area, in which the ball can land. The Roulette wheel also has on or two green pockets. The green pockets has numbers 0 and 00 or only 00, depending on the kind of Roulette.
A roulette dealer (usually referred to as "croupier" spins the wheel counter clockwise and releases what is usually a plastic ball along the track that runs along the top of the wheel's cavity. The wheel loses speed and as a result the ball comes down from the track, bounces a little and then lands in one of the pockets.