The Monty Hall Dilemma

[MetalSwitch95]

It's because there are two goats. So you have a chance of getting either of the goats or the car. Even when one of the goats is revealed you could still get either one of then. So it is still 1 in 3.

[Lpoolboy]

You smoking crystal meth before this vid? You keep stopping all over the place with your speech and the camera shakes violently.

[lesliekwan80]

I don't understand how people can still be so ignorant of the truth. If you don't believe it, then do it yourself. Record your observations. This isn't magic or anything. This is fucking MATH.

[giovea]

i am sorry leslie too disagree. and i am sorry of hoe easy you use insult. i almost see you as an american or brit, unfortunatly that s your way of relating among other people. no it's not magic, but it is not math for sure, is a cross between alledged correct aplication of math and bad interpretation of problems. TRY THIS (you do not need a simulation as it is maths)

Swap and win= Stay and loose=2/3

tht you know from starts. looking at it upside down doen't change a thing. grow up and wise up

[giovea]

dechha... is nice to see someone with head beetwen the shoulders.

you got the hang of it.

[ProtoCosmos]

Lets say I pick door #1 and Monty reveals a goat behind door # 3, then someone else (of whom is unaware of the choice I made) comes in and sees the two closed doors and a goat standing at door #3 .... and also picks door#1..... are the odds then more in favor of the car being behind door #2 ?  And if so, why?

[dechha1981]

The odds have not altered.

[ProtoCosmos]

Can you explain why?

[dechha1981]

Why would you assume the odds have in any way altered just because someone else made a guess? Do you believe that this causes a rift in the space/time conbtinuum or something?

[ProtoCosmos]

Ha ha! In a way, yes! No... but seriously, the odds will have changed. The 2nd person isn't playing a '1 in 3' game like I'm playing... because the option for them to pick # 3 didn't exist like it did for me initially . So I ask you, why would it be beneficial for them to pick door # 2 ? What logical equation defines the probability of the car being behind door #2 for the new person?

[dechha1981]

The odds did NOT change. That would require Reality itself to have altered. That is. it would require the car and the goat to have actually moved.

[ProtoCosmos]

The car and goat are where they are regardless. All I'm asking,is if you can to explain why the 2nd person's chances are/are not 50/50. You can simply exclaim " The odds do not change" But I'm asking for a breakdown of it. If you recognize exactly what I mean but don't know the answer, that's totally cool too.

[giovea]

remaining door X and Y have 2 possible results each (car or goat) . it's a double entry simetrical deal, since you can't guess were you are at...

host can always find a way to reveal a goat, irrelevant besides the fact that eliminates 1 wrong door.

you are double counting if you reconsider it helps you more than that really.

[KemaTheAtheist]

giovea, the monty hall problem is a very common example, and your assumptions are wrong.

It is always in your interest to switch simply because your FIRST choice is made at a 1/3 chance which means you're likely WRONG and the car is in one of the other doors. Everything that follows is a result of that.

Period. Read a book on probabilty.

[giovea]

really man, i am off topic already. i have some college graduations in stats, epidemiology and other associated sciences. i got some books if you wanna swap. as to the matter i made my point quite clear. anyway thanks for the notice\.

you reach the same average cause is a double negative win by swap = loose by stay. you just twist the questions, no work done on the answer (2/3). in fact if it's the same it proves no advantage. no maths required ;) semantics perhaps...

[lesliekwan80]

"college graduations in stats, epidemiology and other associated sciences"

And you're still having trouble understanding a popular propblem that 14 year olds can understand. What shitty community college did you graduate from?

[giovea]

I beg to differ my friend. I am not getting into this again, for sure, but many, many famous mathmaticians have disagreed with this kind of "game show logic" supposed to be the discovery of the Graal. I do not need to be in my toes to argue simple things, but i wont be taugh like a 14 yo.. Most people that post this videos coping a smart ass tryi to look bright. Neither was the lady a genious (although an icon i guess)nor she was corrrect. it's grotesc to see all this gagging around it! ilusion

[lesliekwan80]

Wow, you're stupid. You actually believe it's still a 50/50 chance. Well, if your mind can't wrap around the idea ... then it's hopeless for you. If you don't believe in math, then at least believe in reality. Do the experiment yourself, and you'll see after many trials that the chances aren't 50/50.

[giovea]

you got the period???

[giovea]

Errors:

#1- how the number relates to prize is irrelevant and you dont know and can't know!

#2-if showman knows and always opens a goat door it's also irrelevant too (it's his concern and the branches possibilities remain secret to you).

SO If you left with 2 doors and 1 shot is simple 1/2. Rest is pos-test probability of game developing, not contestant options in the time of switching.

THat's it

[giovea]

ok. dont travel back and fowrd in time. is because you dont know that you calculate in the 1st place.3 doors to begin is concensual 1/3,ok.ok now imagine YOU choose twice, so if you dont get to see door n1 is a simple sequence of 2 like the coins. if you put in a breaking event, 1 door revelead, you have to refigure, not sequence now just single shot 50/50. what happens is pre test , post test and dependent event (sequence)are diferent concepts to really reajust your odds in dinamic situations

[KingHeathen]

this is mostly right. You leave out the rule of randomness. This ignores "odds" and goes with the idea that you are equally likely each time to pick the correct number each time as you are to pick the wrong one. You could conceivably randomly pick the right answer each time. That said, you are more likely to pick the WRONG answer each time. And statistically speaking only, you are 2 times as likely to be better off by switching. But due to randomness, it's 50/50.

Still, statistics wins.

[Gordo1108]

The picking of the door by Monty is non-random

[dechha1981]

Yes it is. I picked the doors and I KNOW it's random

[Gordo1108]

No, I was referring to Monty, the host, he knows which door is the prize and which isn't, He always picks a goat door, so his pick is non-random. We actually agree, I was trying to correct KingHeathen. The only random event is the player's first pick 1/3. Monty's pick is non-random and it determines which door you do or don't switch to.

[giovea]

Bravissimo! kingHeathen

[dechha1981]

I'm kind of waiting for someone to tell me what the score was. I COULD do it myself, obviously, but the idea was that YOU guys keep score, not me.

[KingHeathen]

I counted 6/20 keeping the same door and 12/19 switching (I disqualified one pick as it appeared you chose the same door instead of switching.)

This is fairly close to the 1/3 and 2/3 odds you'd expect, respectively.

[dechha1981]

Thank you!

[giovea]

My point also. The same 1/3 and 2/3 you had at the beggining. OR NOT??? LOL.

Really a semantic inigma :)

[CHAS1422]

It all has to do with Monty having prior knowledge of the correct answer. With your first selection the odds of winning are 1/3 and the odds of losing are 2/3. Monty will never reveal the door you picked so the odds never change. What he does is reveal an empty door on the 2/3 losing subset. If you always employ a "switch" rule, then the only way you lose is when you pick the correct door in the first place!

[Xorinite]

The trick comes in the host always opening a losing door. And that losing door cannot be the door which you have picked.

Thus the chances of the door you picked being a wrong door becomes one in two after the host picks, but the the chances of the other door being the wrong door remains 1/3.. Or something like that.

[giovea]

XOrinite, try to abstract from the game show neurosis. think of that as a weighting machine beeing the door given the balance point. now on one side you have your pick and on the other you have the remaining, it's a clear 1/2. If you wish to look backwards it's obvious that your pick is 1/3 correct so your swapp is 2/3 correct, so how does that help you anyway if you knew that already??? without the results it doesn't. with the results is not oods, just a freaking and odd accident :)

[Xorinite]

Holy fucking shit dude. Did you not read the part which says (1 year ago) how on earth do you expect me to rememeber something I commented on a year ago?

If you want to play a necromancer get WoW with the expansion, don't ressurect year old threads.

[Portiadude]

This is truly a facinating problem, since the answer contradicts common sense. Even mathematicans had a hard time to accept the answer, but the proof was there, so they did.

[QualiaSoup]

Another person who's 'got it'. Great! ;^>

The interactive version of the dilemma you've shown here is different from the one I've linked to in my video description. I'll check it out.

Cheers, Dechha.

[dechha1981]

I just remembered to acc the link in the description

[BayerLexan]

After thinking about it for an hour or so, it sunk in. It has been a topic on my mind that gives me great entertainment, mental masturbation as it where. I thank you much for bring such an interesting idea to me!

[VennomFangX]

The probably that you were wrong on your first pick is 2/3. So the probability of winning when you choose to switch from your original pick is 2/3. If you had 1000 doors and picked one, the probability that the prize is behind the other doors is 999/1000.

[giovea]

VennonmFangX: Of course the probability remains the same. looking at it backwards doens't change it. BUT that was not the dilema actually, in fact that i think is pure math and consensual. The Lady sayd it would be to your advantage to swap, that's is not foward or backwards, that's restart from the middle and for sure it is a dilema but you can't honestly assume an advantage, although a simulacion will confirm your inicial odds