Article on Wheel, Sector and Pocket Bias

A biased wheel is one with a defect resulting in a certain numbers being selected more often than they are supposed to. You can be sure that the casino sees it as a threat, even though it is e.g. zero that is biased. If some writers find out, they will immediately start exploiting it.

For a bias to be worth playing it must be big enough to beat the probability 1/35 €“ even though the frequency - from a mathematical point of view - is 1/37.

A defect on a wheel can be either born or a result of wear €“ usually it is the last. Some defects will favor numbers. This type is called pocket defects while other defects will give whole sectors a higher probability.

A defect, which can result is one pocket having a higher probability, is for example if one pocket is larger than the others. This will off course automatically have a higher probability. However, I haven’t seen this with newer wheels. A pocket defect on a wheel in Germany was due to a tiny edge between18 and 22 resulting in a micro my sticking up over the number plate. The wheel produced many “rollers”, in which case the ball was spinning in the actual outer track. The little edge made the ball hit number 18 to such extremity, because it struck the small edge, and consequently the neighboring number very few times. Both numbers exceeded 3 standard deviations positively and negatively.

A more frequent bias is loosened edges between the pockets. This provides more “sluggish” recoil when the ball hits thus providing this pocket with a higher probability. Repairmen and maintenance people speak of air pockets, such as loose felt in the bottom of the pocket or maybe a double layer of felt€¦(that’s cheating!!)

Sector bias can be caused by something called rotor wobble. The rotor is placed on a spindle, which can be a little crooked due to the daily or weekly cleaning where the rotor is taken of the wheel. A defect can also occur in the rotation at the top of the sides where the ball is spinning to begin with. The defect in the top should produce a more frequented falling zone. This can also be achieved if the wheel is a little out of water. This does not produce biased numbers or sectors, as the random results are secured by the turning of the rotor.

The wobble combined with a defect ball track at the top can on the other hand crease biased numbers or sectors. If the ball lands on the rotor while it is in the lower end of its wobble (you have to imagine a plate on a stick spinning a little crooked), the ball will have tendency to stay there, as it has a harder time running up the plate.

A wobble can be spotted, if for example the rotor is made of polished brass as the ceiling light is reflected. You will quickly spot that it is not even.

Biases in a roulette wheel have a very small impact and usually many aspects are required to match in order to play a bias with profit. Had for example the wheel in Germany, Hittfield, not produced rollers at all, the tiny edge would not have had a great impact. Some of the aspects that need to be considered are:

  1. The dealer
  2. Time of the day
  3. The rotor speed
  4. How the wheel is oriented

Ad 1. It is possible that the dealer throws the ball in a certain way, which might give a side or backwards spin that can affect the circulation of the ball.

Ad 2. The time of the day is important mostly due to humidity and high/low pressure (it does actually have an impact).

Ad 3. The rotor speed is important as well, as some biases will not occur the more the rotor is turning.

Ad 4. The casinos turn and move the wheels from table to table frequently. If you are a pro, you spot the various strange yet recognizable features or marks/scratches either on the rotor or on the wooden sides.

Earlier this year, I was given the opportunity to survey a professional bias team at close range. I played with them for 22 days and sucked knowledge like a crazed man. At one time, we followed a wheel with 2 obvious biases on the rotor. One, where the light reflected on the rotor, suddenly jumped 6 inches as well as another with a slight side effect. At the bottom of the pockets the light from the red readers (laser automatically reading the number in which the ball rests) reflected unevenly on some of the pockets. As a clocker this wheel was interesting €“ not as a bias player €“ as it had a good tilt and provided a fairly okay jump length for the ball. My partners were more interested in the bias. They didn’t start to play till after 2 days and approx. 700 noted spins, and it fascinated me a bit that most of the time they did not play at all. When they did play they adjusted 7 numbers under me, when my prognosis was on number. 28. It turned out that the sector before 28 stole many hits from the 28 sector. The ball would fall on the rotor and roll on, but would never cross the sector ahead of no. 28. This didn’t mean that the 28 sector never had any hits, because when the wheel was turned the other way and the ball came from the other side, it hit just fine. This was a bias that could not be traced by just continually noting down numbers.

This type of bias is not so well known, as it has arisen due to newer wheels with less deep pocket in which case the ball spins across many numbers so to speak before it stops. Previously, the ball would hit the rotor, and then only jump a few numbers.

My partners won USD 4,000 in the course of 2 days. They are pros and work extremely effectively; among others assisted by software and excel spreadsheets. Once the preparations are finished, the games begin!

Their game is a combination of math and old-fashioned visual tracking a la Laurance Scott, which I have mentioned in gaming strategies and modern bias tracking. You get the prognosis visually and adjust to the closest sector, which might have a higher probability, if it is in the area when the ball falls €“ that you know using visual tracking. If you add the numbers to a simple Excel spreadsheet, which some of the casinos use, I am pretty sure that the manager will start to sweat right a way.

I estimate that they won approx USD 20,000 in the course of the 22 days I followed them. 3 divided this. They could have won more with higher stake money, but the question is then, if they would not have gotten to much attention. Surveillance and the croupiers, who - most likely - would have been told to call “no more bets” much earlier, would probably have hindered them.

Bias gaming is not for everyone, but is well established and thrives even today despite Huxley Saturn wheels and Cammegh, which should be almost perfect.

Kelly, a member of (our Danish sister portal), wrote this article.

Article Source:

Dr. Spock

CHEERS :wink:


YOU WROTE" This type of bias is not so well known, as it has arisen due to newer wheels with less deep pocket in which case the ball spins across many numbers so to speak before it stops.


What latest updates do you do you have on this newer type of bias identified by advantage players like yourself? This is so new that the casinos with the newer TCS John Huxley wheels have not yet identified this as a possible problem. I say we have a 3 to 5 year curve or longer before they even realize it - - - and a 7 to 10 year curve before something is actually done to fix this scatter bias.


I wrote the article a couple of years ago in Danish language to S ¸ren from Casinoportalen. He never said it was going to be run through a german and a english free translation machine. So basicly the language sucks. All he had to do was ask for a english and a german version, and i could have wrote it.

I really regrets writing the article because even though i just scratch the surface, the subject is highly sensitive and holds the key to the strongest VB play you are ever going to find. The good part is that the casinos don`t know how to handle the info you can get this way.

What i regret most, is that i purchased Snowmans material some 6 months AFTER my tour with mr “P” and his team. If i had had the knowledge of snowman before joining the team, i would prrobably have learned A LOT more.

The Casino analyze the numbers and the drop zone with software. The level they use to measure the wheel tilt is either a high precision level with a 4 point balance window or a 3 legged monster where each of the 3 legs is placed in the ball track or on the top rim.
They use a flexpost arm/dial indicator for fine adjustment of the rotor. It will check the height of the seperators, and will allso measure the “rise and fall” off the rotor. Accuracy down to .001 inch. A depth micrometer is used for measuring the depth of each pocket in relation to each other and an internal caliper gauge with 2 outward measuring arms with a pre set dial indicator to measure the the space between each seperator in relation to each pocket.

So they certainly got the tools, but they dont know how to handle the info, if they knew, i think traditional Roulette would probably be taken off as table games. Despite all their fine tools, they are not going to eleminate certain things and unbalances because the mecanic check as described above is not done as a weekly check if there dont appear to be any biased numbers, then they will just hoover the pockets and clean the bowl and rotor until they all appear clean nice and shiny.

Any updates is not leaving my computer, its simply too sensitive and there are actually people who have their daily income from from this kind of game.

PS: The “Scatter bias” can already be fixed to an extent where ALL of us might as well go home, fortunately not many knows how to do that.