Roulette Results - How many spins do casinos use to determine the unbiasness of a roulette wheel?

I know the next spin is independent from the last so how can a casino determine that a wheel has a bias? How many spins do the casinos use to determine this? Can't there be a sleeper or a hot number during an infinite period since each spin is independent regardless of each number having the same odds of coming up?

There's gotta be a number right? 100k, 1 million spins?

If we know that number and say we're 10k short of that number and know that on a single zero roulette table that number 25 has been a real cold number so far, representing only 2.2% versus the 2.7% that is expected. And knowing that there should be no bias to the wheel shouldn't it go on a hot streak for the remaining 10k of spins more so than the 36 to 1 that is on offer if we start flat betting?

The above might be too extreme and exact.

Even if say the casino accepts 2.6% during a finite period to determine if a wheel is bias or not, can't we try to find a cold number that represents 2.4/2.5% and know that it needs to get to 2.6% by a finite period?

Quote: WizardofAus

And knowing that there should be no bias to the wheel shouldn't it go on a hot streak

You just decribed Gamblers Fallacy. Whenever you use
the word 'should' to describe a game of random chances,
you're making the oldest mistake in gambling.

I'm surprised at all of your Roulette questions....... as the WizardofAus you should already know the answers!

Thanks for the replies guys. I understand all the Math's and about the long-term and that anything can happen probably will happen over the test of time but what is the number the casinos use. If they use 100,000 and they find that number 25 only represents 2.4% dorsn't that mean a bias? Can you please read my question and what it really is asking. I know the Wizard does some work for casinos and I'm sure others do as well do hopefully someone can let us know. Cheers.

While I don't know the actual number, the following is a screen shot from TCS John Huxley's website on wheel analysis.
(FYI: TCS is the premier manufacturer of Roulette wheels among other things.)



It's impossible to know if that chart represents actual data, or spcific data fed in to make an interesting chart.

It's blurry, but I *think* it says that this is for 2,000 spins - but that still doesn't answer the question.

Quote: WizardofAus

can't we try to find a cold number that represents 2.4/2.5% and know that it needs to get to 2.6% by a finite period?

You are barking up the wrong tree here. If a number is cold, that does not make it "due to come up". If a number has been cold, by the time you have the data for 10 billion spins, say, the number will get back much closer to the expected percentage, sure. But the way that will happen will be by burying the significance of the sequence of spins that showed it cold. The 10 billion spins will just bury that anomaly by larger numbers. The odds that the coldness will be 'corrected' by a period of being hot or no better than the number staying cold, in the short run. Furthermore, if the number never gets hot, the percentage will still 'correct'.

What you should be trying to do is determine if there is a bias in the wheel, if you are serious. That would probably be a sector rather than a number. My gut tells me that you probably need about 10 million spins to start to get fair certainty on that. Also, it is said casinos are 'all over it' when it comes to handling biased wheels these days.

I guess more for curiosity's sake than anything else, I'd love to know how many spins are used to determine the "Hot" and "Cold" numbers as seen on this history display.

Only a fast dealer with few players can get more than one spin a minute. Usually it's more than a minute between spins. I once witnessed a full 7 minutes between spins on a packed table. Therefore, this has to represent a full day's spins, or perhaps even more.


Note that because of the style of lettering, it didn't photograph well. It was much more readable live.

Quote: DJTeddyBear

I guess more for curiosity's sake than anything else, I'd love to know how many spins are used to determine the "Hot" and "Cold" numbers as seen on this history display.

Only a fast dealer with few players can get more than one spin a minute. Usually it's more than a minute between spins. I once witnessed a full 7 minutes between spins on a packed table. Therefore, this has to represent a full day's spins, or perhaps even more.

Note that because of the style of lettering, it didn't photograph well. It was much more readable live.

Cammegh's Billboard Display system defaults to 300 but can be customized.
EFXvLCD Roulette has options for last 100 spins, today,last 30 days and since last reset.
CYCLOPS Looks like for hot 1000 and is says how many times. For cold it says how long it has been

Quote: WizardofAus

I know the next spin is independent from the last so how can a casino determine that a wheel has a bias?

You seem to say that you know each spin is independent but your question implies that there is somehow a "should-happen" event and that you think it should take place on the next spin to "balance out the world" or something and make all things right with the universe.
Well, it might just happen on that next spin.... or the tenth one from now. ... or never.

No casino ever shows the "hot" numbers or "cold" numbers on their annunciator panels. They show you the recent history and let you decide if three reds in a row means anything about the next spin.

Its like the Baccarat graph paper the casino distributes and that tiny golf pencil. They provide the little squares but they don't tell you that charting the game and trying discern the results will aid you on your next bet. Sure its been Player for "x" hands. That doesn't mean Banker is "due"... that next hand may still be Player.

Quote: FleaStiff

No casino ever shows the "hot" numbers or "cold" numbers on their annunciator panels. They show you the recent history and let you decide if three reds in a row means anything about the next spin.

Actually some casinos do show you the "hot" and "cold" numbers and they use those specific words.