The Monty Hall Dilemma

You keep score
http://www.math.ucsd.edu/~crypto/Monty/monty.html

Category:

Entertainment

Tags:

• Monty
• Hall
• Dilemma
• odds
• door
• host
• gameshow
• doors
• goat
• car

[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.

[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.

[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.

[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.

[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.

[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

[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 :)

[giovea]

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

Really a semantic inigma :)

[giovea]

Bravissimo! kingHeathen

[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

[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.

[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.