Unlevel or bias Roulette

Wiz,

You are the best. I have been reading the wizardofodds.com for years. You are a real standout in the gaming world.

We have been studying roulette behavior and following the repetition of sectors on specific roulette wheels. Please note; this comes from a management perspective and not a player, but could help players develop winning strategies.

We have an ongoing debate on the precision to which we must level our wheels.

After numerous carefull statistic sampling (200-500 spins) based on player follow-up, we found a possible relationship between a slighty unlevel wheel and the ball favoring a sector. We inicially noticed this behavior on highly sectored results. We noticed that on a less than level wheel the ball falls into the spinning cilinder within 1/4 of the wheel. So after 20 plus spins around teh cilinder, the ball falls within the same 1/4 up to 23 balls in a row and then repeats again.


The specific question is: If the ball falls within 1/4 of the spinning wheel on a very consistant basis, say 80% of 200 plays, what is the change in probability or player advantage if any?

Thanks!

Tom

Just to make sure I am clear: The bias we are seeing is in the drop zone. When teh drop zone is consistently in 1/4 of a wheel, what is the risk or change in our odds?


Thanks,

Tom

A related question. Is there a standard definition of Octet and Quarter. In other words, is there an officially defined starting place from which to measure eight numbers? How would this change for a single zero versus double zero wheel. I've often seen a single zero wheel depicted with the zero at the top but don't know if this is standard.

As to bias and leveling, I don't know how often casinos vacuum the carpets and have to move the table to do so but I sure hope they make sure the wheel is level afterward. I think one of the most profitable things a casino could do would be to spread rumors that their roulette wheels were biased in some manner, just as the casinos try to keep players thinking about "loosest slots".

Thanks for the kind words. I think the question you should be asking is the result of a chi-squared test of your results. I can do that for you if you post the results of your 200-500 spin survey. However, to answer your question, if the wheel really did favor 25% of the numbers with 80% probability, then bet each of the numbers in that 25%. I might add that 25% does not go into 37 or 38 evenly, but we'll ignore that. On a 37-number wheel the probability of winning would be .8*(4/37)=8.649%. Your advantage would be 211.35%! On a 38-number wheel the probability of winning would be .8*(4/38)=8.421%. Your advantage would be 203.16%.

If something sounds too good to be true, then...

Wizard,

Thanks for answering.

I need to clarify the question. The bias wheels and samples of data do not reflect a favouring of 25% of the numbers. That would be the huge 211% player advantage. That is not what I am trying to describe.

The drop zone- The area of the cylinder where the ball drops into the spinning disk with the numbers.

When the roulette wheel is not level it favours 25% of the drop zone. The spinning disk with the numbers always receives the ball from the same zone in. How can this affect the probabilities of a zone in the spinning disk?

I hope this is a bit clearer.

thanks,

t

what i think he is trying to say, is the ball is dropping out of its spin from the outside of the wheel in the same 1/4 most of the time. the ball can then travel further roundon the edge of the wheel, or as it is falling. or get knocked by one of the slots to change direction etc.

i dont think it would be possible to work out an edge you might have giving only the drop zone. because the ball can still do pretty much whatever it likes after its started to fall. its a lot easier to see where it might land, but thats gonig to be to a different degree of certainty on every wheel, surely.

if your able to, maybe spine it 1,000 times where the ball goes clockwise, and log every number it lands on when it drops in the 1/4 of a dropzone ou mentioned... then try the same again spinning the ball anti clockwise.

im sure an edge may be able to be worked out then.

Quote: pingu

what i think he is trying to say, is the ball is dropping out of its spin from the outside of the wheel in the same 1/4 most of the time...

This is starting to sound like a physics question, which I won't even touch.

Quote: Wizard

This is starting to sound like a physics question, which I won't even touch.

F = m X a

You're welcome.

Quote: jibaro

The specific question is: If the ball falls within 1/4 of the spinning wheel on a very consistant basis, say 80% of 200 plays, what is the change in probability or player advantage if any?

Assuming the bumps and ridges within the disk and cylinder do their job, the outcome should still remain random. It is similar to a craps shooter setting the dice in the same way and tossing them into the same narrow area of the table. As long as the "pyramids" that line the walls of the bowl do their job, the outcome should be sufficiently randomized.

To test the game integrity, I would want to know two things:
1) Is there a trend in the outcomes. In other words, regardless of the platter position when the ball drops, are the final numbers evenly distributed? Apparently, the final outcomes are evenly distributed, so the only other opportunity for a player advantage would involve, knowingly or unknowingly, the dealers...

2) Do you observe dealers skilled enough, or consistent enough, to spin the platter and ball in a manner that produces correlated outcomes? More important, does the dealer's behavior result in actionable outcomes? Does the quarter of the wheel the ball initially drops into, correspond to a narrow (less than half) sector of final outcomes? If so, you have a problem. The game can be beaten.

Thanks for your answers and the clarifications. Yes, the observation is the drop zone. It is a phsics question, but has mathematical implications. I beleive a consistent "drop zone" must reduce the randomness of the roulette.

If you can observe the crossing point of the ball and a segment of numbers on the disk at the drop zone, you may be able to calculate what segment of numbers will be passing through the drop zonewhen teh ball drops and bet that segment. This would take way 75% of the randomness of the drop zone, leaving only the speed of the disk and time the ball is spinning.

As a dealer: If you have a consistent number of spins (time), you know the drop zone, then you may be able to control the spin of the disk as to time the number of spins or total amount of time the disk is spinning as to a half the randomness of the result if you can.

Ayecarumba: Answering your questions:
1) Yes there is a trend although not limited to one zone or half of the disk. The trend shows grouping of results in one or more zones: voisins or tier.

2) One observation is very consistent speed of disk spins by dealers.

Thanks again for your time. I will get you all an example of a session where the drop zone was always withing 25% of the cylinder.