The roulette wheel is a masterfully laid out, and most often, a beautifully engineered piece of equipment. A perfect balance in design is needed so that the wheel does not have, or will not develop, any inconsistencies or biases. Many a hearty gambler has tried to seek out a 'biased wheel' in their day in an attempt to gain an advantage. Since roulette
wheels like all well used pieces of equipment show some wear and tear after a while, it's possible to conceive of a wheel where the wear and tear produces certain number hits more often than chance would allow. If you find one of these you could easily exploit it and make some free money. Casinos know this of course, which is why it's next to impossible to find a biased roulette wheel. In fact, it's next to impossible to even test for one. In order to determine if a wheel has a bias you would need to have a computer watching it for a little while, and casinos don't take kindly to any computer mechanisms on the gaming floor. It's even rumored that casinos constantly scan the casino floor and their security systems pick up any digital device emitting a signal. I wouldn't put it past them.
Our roulette wheel diagram clearly shows the distribution of numbers around the wheel.
American Roulette Wheel
The numbers are ordered to achieve as much balance between high and low, red and black and even and odd. The compartments are called pockets. On European roulette wheels there are 37 pokets, and in American Roulette, the wheels have 38 pokcets. That's because American roulette includes the "00" or Double-Zero pocket. Zero and double zero are both green pockets, while the remaining 36 are split evenly between red and black. As the roulette wheel diagram illustrates, directly across the wheel from every odd number is the next highest even number. Black and red alternate, pairs of even numbers alternate with pairs of odd numbers, except around the zero pockets.