Published on 24 January 2013
A roulette wheel is donsidered biased when it has some sort of defect that results in certain numbers being selected more often than they should. There are different types of defects that can cause the wheel to be biased.
One type of defect is a pocket defect which is often a result of wear. In this defect, some numbers are to be favoured. It only affects a smaller portion of the wheel where a smaller group of numbers appear more often. Sometimes a pocket can become larger which makes the ball to land in the pocket.
Mostly, the cause of a biased roulette wheel is due to the edges between the pockets being loosened. When the ball hits, the recoil is slower which means the pockets affected are more likely to be selected.
Rotor wobble can also be reason for a roulette wheel to be biased towards an entire sector. The rotor is placed on a spindle. A spindle can become slightly twisted because of cleaning, where the ball is more likely to fall into a particular slot. Spot can also be a cause of a defect. Most of the time the rotor is highly polished brass. You can detect it when the ceiling lights is reflected into it. Mostly, this type of wheel is not being used anymore.
Land based casino are the only site that has a problem of a biased roulette wheels. Online roulette dont have this problem because it uses a random number generator.