# What is the mathematical chance of this?

#### hakapuku

##### Banned User - repeated violations of rule 1.14 (tr
I played today at one MG casino. I placed 100\$ bets on red 20 times. It only hit red 3 times and 17 times it hit black. Can somebody ,who knows roulettes' mathematics, tell me if this result is normal or may be something is rigged here?

#### RobWin

##### closed account
I played today at one MG casino. I placed 100\$ bets on red 20 times. It only hit red 3 times and 17 times it hit black. Can somebody ,who knows roulettes' mathematics, tell me if this result is normal or may be something is rigged here?

I believe if i'm not wrong that when you are straight betting only Red or Black then your odds will always be 50-50 of hitting either or at any given spin...maybe Slotswizard will jump in here and help...Slots, where you at man ?

#### winbig

##### Keep winning this amount.
I played today at one MG casino. I placed 100\$ bets on red 20 times. It only hit red 3 times and 17 times it hit black. Can somebody ,who knows roulettes' mathematics, tell me if this result is normal or may be something is rigged here?

20 spins? You can't tell anything from that sample size.

Even so, did it hit red 17 straight times and black 3? Or 6 red, 1 black, 5 red, 1 black, 6 red, 1 black? ... you get the picture.

If the picture isn't too clear, then here: What it boils down to is the fact that you're looking for the probability of one color hitting X number of times before the other color comes up, and not "Is it rigged if I lose 17 out of 20 spins?"

Check out

Random Roulette Spins

Before you waste your money testing a betting system in the casinos please use the following computer generated spins. Remember, it takes about 10,000 or so spins before the ups and downs start to average out and you see that no betting system can survive the long run.

Also -

The probability of red winning 20 times in a row in roulette is (18/38)20 = 1 in 3,091,874. Thus, if red has already hit the last 19 spins the odds are that the next spin will almost certainly be black because of the long shot against 20 reds.

First, the odds of 19 reds in a row and then a black are the same as 20 reds in a row. The past does not matter. The probability of red after 19 reds is 18/38.

edit: Judging by your posts from several months ago, it seems that you thought MG software was rigged, even back then. Why continue to play at MG casinos if that was your thinking?

#### LOOKAWAY

##### Dormant Account
PABnonaccred
Maybe i would not say odds and replace it with chance.

But maybe 50/50 from here to the end off time would be more right. Depending on how long our beautiful planet can hold out for, But im guesing it will go out on a black hakapuku.

But i do find at 3dice roulette plays out like that 1 colour in a row over and over again.

Its findind that colour then switching to other then going back and you get it over and over again, Most times when you play.

#### Slotster!

##### I predict a riot.
It's not 50/50, that's the mistake most people make with roulette. There's a green there for a reason

#### SlotsWizard

##### Dormant account
Keep in mind that 20 spins is so small a sample that it is statistically useless.

Zoozie, aka23, and/or others should be able to tell you the correct figures with certainty.

#### RobWin

##### closed account
It's not 50/50, that's the mistake most people make with roulette. There's a green there for a reason

Yea, you're right Slotster, I forgot about the 0 or 00, so you would have to factor that into and divide by the amount of red and black numbers on the board then ?

#### bryand

##### Beach Bum
I played today at one MG casino. I placed 100\$ bets on red 20 times. It only hit red 3 times and 17 times it hit black. Can somebody ,who knows roulettes' mathematics, tell me if this result is normal or may be something is rigged here?

I get 0.65%

#### hakapuku

##### Banned User - repeated violations of rule 1.14 (tr
There were not any ZEROs in my play

#### winbig

##### Keep winning this amount.
There were not any ZEROs in my play

When you're calculating odds/probabilities, what happens during a session doesn't come into the equation

ie: Even though 0/00 didn't come up while you were playing, they still had a chance to hit.

#### hakapuku

##### Banned User - repeated violations of rule 1.14 (tr
It doesn't matter if 0 and/or 00 comes up during actual play when you're calculating probabilities of an event happening.

Try to throw the coin 20 times. You can do it many times. I think it will take at least a couple of weeks of non stop throwing before you can get the result that I had today.

#### Slotster!

##### I predict a riot.
There were not any ZEROs in my play

But your play wasn't nearly enough... and they still factor into the overall odds of roulette.

Put simply, your experience is not that unusual at any roulette table, in any casino - online or off.

#### Slotster!

##### I predict a riot.
Here...

Great, great example of our limited understanding of probability...

I don't think the video runs long enough to explain how it works - but they explained it later in the show.

#### hakapuku

##### Banned User - repeated violations of rule 1.14 (tr
Here...

Great, great example of our limited understanding of probability...

I don't think the video runs long enough to explain how it works - but they explained it later in the show.

yes , this video reminds me of a numerous microgaming sessions I had lately. Should I take a video of this too?

#### kakata

##### Banned User - hyper flamming
PABaccred
PABnonaccred
PABnoaccred
Ive watch it all.........very interesting and entertaining.......lol

#### KasinoKing

##### WebMeister & Slotaholic..
webmeister
PABnonaccred
CAG
MM
I make it 155/1 against, or 0.645%

But I could be wrong - it's late & I'm very tired! :baby:

#### I<3Microgaming

##### Dormant account
Yeah it's about 0.65%. Rare, but nothing at all "impossible"...

#### cslate

##### Banned User - potty mouth flaming
well that is normal for a online casino ,,,,how did ya do before you played this game.....????

you will not win...you have shown a nice example

#### happygobrokey

##### Dormant account
Try to throw the coin 20 times. You can do it many times. I think it will take at least a couple of weeks of non stop throwing before you can get the result that I had today.

that would be taking those games as severable from the rest of eternity. by confining the test to serial bunches of twenty, yes it is difficult to achieve. but if you took 1000 tosses as a continuous sequence and looked therein for any group of twenty that has the properties of your experience, you'd likely find it.

would you question it had you been betting black and won 17/20? if you keep playing, you'll get a run like that sometime too. it's totally fair what happened, and would the game be much fun to play if you won even money on exactly half your spins in every session you played?

and if the event is 1 in 156 or .65%, that really isn't long odds. if only you were "following the shoe" and betting for a repeat of the last colour each time. but on the bright side, at least you didn't tilt and martingale, chasing the equaliser til you're break-even or broke. the wheel, she is cruel.

#### aka23

##### Dormant account
I played today at one MG casino. I placed 100\$ bets on red 20 times. It only hit red 3 times and 17 times it hit black. Can somebody ,who knows roulettes' mathematics, tell me if this result is normal or may be something is rigged here?
Assuming single-zero roulette, there is a 0.16% chance of exactly 3 reds in 20 spins, and a 0.19% chance of 3 or fewer reds in 20 spins.

#### bryand

##### Beach Bum
Assuming single-zero roulette, there is a 0.16% chance of exactly 3 reds in 20 spins, and a 0.19% chance of 3 or fewer reds in 20 spins.

Did you use: (n)r = n!/(n-r)!

#### SlotsWizard

##### Dormant account
Thanks aka23, you confirmed my math. Shortly after posting yesterday, I edited out my numbers because I wasn't sure if they were correct.

combin(20,3) * (18/37)^3 * (19/37)^17 = 0.1585% ≈ 1 in 635

Although, this formula includes the possibility of having hit a zero, which he says he did not. Knowing this and excluding it from the equation, would you agree that the probability becomes 0.063% ≈ 1 in 1,591?

#### aka23

##### Dormant account
Did you use: (n)r = n!/(n-r)!
I used combinations, not permutations. This results is the formula SlotsWizard lists above.

#### aka23

##### Dormant account
Thanks aka23, you confirmed my math. Shortly after posting yesterday, I edited out my numbers because I wasn't sure if they were correct.

combin(20,3) * (18/37)^3 * (19/37)^17 = 0.1585% ≈ 1 in 635

Although, this formula includes the possibility of having hit a zero, which he says he did not. Knowing this and excluding it from the equation, would you agree that the probability becomes 0.063% ≈ 1 in 1,591?
I believe the result of the equation listed above is 0.1576%, rather than 0.1585%. I agree that the chance of 3 reds, 17 blacks, and no 0s is 0.063%. However, the original poster seemed concerned with the low number of winning hands (reds), so I think it is more appropriate to treat it as the chance of 3 wins or less in 20 spins. This value is...

combin(20,3) * (18/37)^3 * (19/37)^17 +
combin(20,2) * (18/37)^2 * (19/37)^18 +
combin(20,1) * (18/37)^1 * (19/37)^19 +
combin(20,0) * (18/37)^0 * (19/37)^20

#### SlotsWizard

##### Dormant account
I believe the result of the equation listed above is 0.1576%, rather than 0.1585%.
You're right - it does. I was using Dubya's patented "fuzzy math".

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