Statistics Question - Beating Roulette

[dmw16]

Ok, so this question came up at work today over coffee and was inspired by this get-rich quick person we like to mock.

They said, they found this system to beat Roulette and I am having trouble convincing myself they are wrong even tho I feel like they are.

So here is how it works:

Watch the Roulette table and after black comes up 4 times in bet on Red. The "emotional" logic would say the odds are black coming 5 times a row is very low, but the pure logic side of me says that 4 blacks in a row doesn't cause red to come up because each spin is a totally independent set of odds.

All that said, I am not a statistician and have only taken an intro to stat class. So can someone with more background weigh in on why this is BS or maybe totally valid?

 

[IHateMyJob2004]

gambling is a tax for those that don't understand math.
lottery tickets are a tax for those that don't understand math.

 

[jdobratz]

The roulette spins are completely independent of each other, the previous spins have no bearing on the current one.

 

[alexeikgb]

That guy is an idiot... previous spins have ZERO effect on the next. Like you said they are all independent. I once saw at least 10 blacks come up in a row.

 

[ultimatebob]

Right... there is no way to "beat" Roulette. On a properly calibrated wheel, each number has the exact same odds of coming up each time. Even if red comes up 100 times in a row, the chances of red coming up again on the 101st time are still the same.

Would I bet on black anyway? Sure... if I already had a few drinks at that point and I'm looking to have a good time. That's the point of going to a casino, right?

 

[dmw16]

I know gambling is not a sound "investment" nor are lottery tickets. However, going to the casino for a night with your buds is fun as long as you see it for what it is...entertainment.

Yes, each spin is independent, but I can't shake the feeling that while the odds of black coming in any one spin are (we'll say for the sake of argument) 1/2, but the odds are black coming 5 times in a row is 1/(2^5). So are you betting against a string of events?

Like I said, my logic tells me that it is total bull, but I have an this feeling it isn't. I am not gonna run to the casino, but I am looking for a valid, numerical explanation to convince me I guess.

 

[darkxshade]

If you want to win, bet on black

 

[Whisper]

Originally posted by: dmw16
I know gambling is not a sound "investment" nor are lottery tickets. However, going to the casino for a night with your buds is fun as long as you see it for what it is...entertainment.

Yes, each spin is independent, but I can't shake the feeling that while the odds of black coming in any one spin are (we'll say for the sake of argument) 1/2, but the odds are black coming 5 times in a row is 1/(2^5). So are you betting against a string of events?

Like I said, my logic tells me that it is total bull, but I have an this feeling it isn't. I am not gonna run to the casino, but I am looking for a valid, numerical explanation to convince me I guess.

Technically, you could use the same logic to show that 4 blacks followed by 1 red is just as difficult a string as 5 blacks in a row, given that black and red both have the same number of spaces on the board.

 

[HardcoreRobot]

not this again

if the wager was 5 blacks IN A ROW, that would make sense
but that is not the case, each spin is a single event that is not influenced in any way by the previous spins (and all the bets are for a SINGLE spin)

 

[lizardboy]

Wired shoe helps gambler cheat at roulette

http://www.engadget.com/2005/0...ler-cheat-at-roulette/

 

[darkxshade]

Originally posted by: dmw16
I know gambling is not a sound "investment" nor are lottery tickets. However, going to the casino for a night with your buds is fun as long as you see it for what it is...entertainment.

Yes, each spin is independent, but I can't shake the feeling that while the odds of black coming in any one spin are (we'll say for the sake of argument) 1/2, but the odds are black coming 5 times in a row is 1/(2^5). So are you betting against a string of events?

Like I said, my logic tells me that it is total bull, but I have an this feeling it isn't. I am not gonna run to the casino, but I am looking for a valid, numerical explanation to convince me I guess.

It depends on how you look at it really. Technically the 4 that came up in a row has already happened and if you want to thinks statiscially you cannot include them. The next spin will be 50% and the chance of getting another 2 in a row is 25% and so on and so forth and that's always the case no matter what happened previously. Or you can think about it like a broke man does and think oh it's already came up 10 times in a row, the chances of it happening 1 more time is like 1%, casino loves people like these.

 

[dullard]

The chance of the NEXT five colors being black is low (but not that low). There is a 2.7% chance of that occuring (1 green number) or a 2.4% chance (2 green numbers) depending on the type of Roulette you are playing.

The chance of the PREVIOUS four colors being black at that point is 100%.

For the emotional case, you have to balance a 2.7% chance with the 100% chance. Weigh the two scenarios and realize that in the end, the chance of the next one being black is somewhere between 2.7% and 100%. In fact, it should be just about in the middle. You'll eventually see emotionally that there is a 49% chance that the next one will be black (47% for American roulette).

Mathmatically, you can just go right to the facts: if it is a fair wheel, there is a 18 / 37 = 49% chance that the next one will be black (47% for American roulette).

 

[MikeyLSU]

good ole rock, nothing beats rock

doh

 

[dullard]

There is one way to statistically beat roulette.
1) Find an idiot who follows the emotional method.
2) Bet a second idiot about whether the first idiot will pick black or red.

That is a game you can win in the long term.

 

[dmw16]

Thank you. That should work to convince the office dumb-dumb

 

[Legendary]

http://en.wikipedia.org/wiki/Gambler%27s_fallacy

 

[evident]

while the math in roulette is pretty clear to many people here,
don't forget about the mechanical aspect of roulette though. a good dealer(spinner) can time their roll pretty well and have a couple "favorite" numbers

 

[dmw16]

Originally posted by: Legendary
http://en.wikipedia.org/wiki/Gambler%27s_fallacy

perfect!

 

[TankGuys]

I love roulette - my wife and I won handsomely on our honeymoon. The difference was, we realized it's *entirely* random. I got quite a kick out of the 3 different people who sat down beside me, telling me the "best strategy". One lady swore it was best to play one single number. The next guy had a strategy similar to what you are talking about. The third person said something about betting blocks. I couldn't help but find humor in the fact that all three of them ran out of money while I kept winning. Even that was purely luck

The thing about roulette, in my mind (and If I'm wrong, someone feel free to correct me - it's been quite a few years since I took stats) is that it makes basically no difference how you bet. You can randomly throw chips out onto the board, and you'll do the same, in the long run, as any strategy. Since any given bet you make has a payout tied directly to the odds of it landing, the specific bets are essentially irrelevant.

 

[Chryso]

Originally posted by: dmw16
Yes, each spin is independent, but I can't shake the feeling that while the odds of black coming in any one spin are (we'll say for the sake of argument) 1/2, but the odds are black coming 5 times in a row is 1/(2^5). So are you betting against a string of events?

You aren't betting on five blacks in a row. You are betting on one black on one spin.

 

[Scarpozzi]

Betting just because a particular number or color comes up a couple of times won't increase or decrease your odds.

After watching that show "Breaking Vegas"....they concluded that the only way to do it is to increase the sample size on a particular wheel. There was a family that all staked out different roulette wheels in Madrid. They sat there and recorded the numbers that hit until they had records of 3000-5000+ spins. They kept track of the wheels by table numbers, as well as any marks on the wheels themselves...

They entered all of the results into a computer and calculated which numbers were statistically higher odds on any particular wheel. Of course, if a wheel was moved to a different table, the balance of the wheel would be compromised slightly, but it still might pay out if the internal balance was part of the contribution to the numbers rolled.

So...they basically split up, as a family and bet on the numbers the computer calculated and they won...until they got kicked out. The down side to breaking roulette is the persistance it requires to win and you WILL get recognized.

 

[Farang]

I think I learned about this in 2nd grade.

 

[M0oG0oGaiPan]

roulette -ev

 

[Toasthead]

ive seen black come up 13 times in a row....more than once

 

[Toasthead]

Originally posted by: dmw16
I know gambling is not a sound "investment" nor are lottery tickets. However, going to the casino for a night with your buds is fun as long as you see it for what it is...entertainment.

Yes, each spin is independent, but I can't shake the feeling that while the odds of black coming in any one spin are (we'll say for the sake of argument) 1/2, but the odds are black coming 5 times in a row is 1/(2^5). So are you betting against a string of events?

Like I said, my logic tells me that it is total bull, but I have an this feeling it isn't. I am not gonna run to the casino, but I am looking for a valid, numerical explanation to convince me I guess.

yes, but its ALREADY come up black 4 times, so those spins are taken out...the odd of it coming up BLACK BLACK BLACK BLACK RED are just as incredible.