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Thread: [Wednesday] Big brain exercises

  1. #1
    Movember 2011Movember 2012 Nordstern's Avatar
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    [Wednesday] Big brain exercises

    Been reading up on the Monty Hall problem, and it's more than a bit confusing. But it was made a bit easier when pointing out the standard assumptions: that the game master has certain behaviors that they need to perform, which are not random. As I understand it, the solution is not "you have a 2/3 chance of winning the prize if you switch doors", but "the game master has a 2/3 chance of actively avoiding opening the door with the car, therefore you should pick the door he did not". The game master's door choice is biased by yours.
    Last edited by Nordstern; August 23 2023 at 05:26:19 AM.
    "Holy shit, I ask you to stop being autistic and you debate what autistic is." - spasm
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    WTF I hate white people now...

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    tulip's Avatar
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    Quote Originally Posted by Nordstern View Post
    Been reading up on the Monty Hall problem, and it's more than a bit confusing. But it was made a bit easier when pointing out the standard assumptions: that the game master has certain behaviors that they need to perform, which are not random. As I understand it, the solution is not "you have a 2/3 chance of winning the prize if you switch doors", but "the game master has a 2/3 chance of actively avoiding opening the door with the car, therefore you should pick the door he did not". The game master's door choice is biased by yours.
    Sticking with your original choice after one door is removed has exactly the same odds as switching door. Because deciding not to switch is as much a choice as switching and is made after the third door has been discarded therefore sharing the same 1/2 chance.
    Quote Originally Posted by Tarminic View Post
    Just for the record, "sending a needy text" is never the right answer.

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    Quote Originally Posted by tulip View Post
    Quote Originally Posted by Nordstern View Post
    Been reading up on the Monty Hall problem, and it's more than a bit confusing. But it was made a bit easier when pointing out the standard assumptions: that the game master has certain behaviors that they need to perform, which are not random. As I understand it, the solution is not "you have a 2/3 chance of winning the prize if you switch doors", but "the game master has a 2/3 chance of actively avoiding opening the door with the car, therefore you should pick the door he did not". The game master's door choice is biased by yours.
    Sticking with your original choice after one door is removed has exactly the same odds as switching door. Because deciding not to switch is as much a choice as switching and is made after the third door has been discarded therefore sharing the same 1/2 chance.
    It's been proven both mathematically and experimentally that switching is the best strategy.

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    I find it strange that people think this as strange.

  5. #5
    Movember 2011Movember 2012 Nordstern's Avatar
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    Quote Originally Posted by tulip View Post
    Quote Originally Posted by Nordstern View Post
    Been reading up on the Monty Hall problem, and it's more than a bit confusing. But it was made a bit easier when pointing out the standard assumptions: that the game master has certain behaviors that they need to perform, which are not random. As I understand it, the solution is not "you have a 2/3 chance of winning the prize if you switch doors", but "the game master has a 2/3 chance of actively avoiding opening the door with the car, therefore you should pick the door he did not". The game master's door choice is biased by yours.
    Sticking with your original choice after one door is removed has exactly the same odds as switching door. Because deciding not to switch is as much a choice as switching and is made after the third door has been discarded therefore sharing the same 1/2 chance.
    A common misconception (one that I had) based on the assumption that everything in this scenario is random, perpetuated by the fact that Savant didn't explicitly state some basic facts:

    The host must always open a door that was not picked by the contestant.
    The host must always open a door to reveal a goat and never the car.
    The host must always offer the chance to switch between the originally chosen door and the remaining closed door.

    These were implied when the thought experiment stated that the host knows what's behind each door and always opens a door for a goat. This is therefore not random behavior.

    It's confusing at first, but read the Wikipedia article thoroughly and you'll understand.
    "Holy shit, I ask you to stop being autistic and you debate what autistic is." - spasm
    Quote Originally Posted by Larkonis Trassler View Post
    WTF I hate white people now...

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    Caldrion Dosto's Avatar
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    Quote Originally Posted by Nordstern View Post
    Quote Originally Posted by tulip View Post
    Quote Originally Posted by Nordstern View Post
    Been reading up on the Monty Hall problem, and it's more than a bit confusing. But it was made a bit easier when pointing out the standard assumptions: that the game master has certain behaviors that they need to perform, which are not random. As I understand it, the solution is not "you have a 2/3 chance of winning the prize if you switch doors", but "the game master has a 2/3 chance of actively avoiding opening the door with the car, therefore you should pick the door he did not". The game master's door choice is biased by yours.
    Sticking with your original choice after one door is removed has exactly the same odds as switching door. Because deciding not to switch is as much a choice as switching and is made after the third door has been discarded therefore sharing the same 1/2 chance.
    A common misconception (one that I had) based on the assumption that everything in this scenario is random, perpetuated by the fact that Savant didn't explicitly state some basic facts:

    The host must always open a door that was not picked by the contestant.
    The host must always open a door to reveal a goat and never the car.
    The host must always offer the chance to switch between the originally chosen door and the remaining closed door.

    These were implied when the thought experiment stated that the host knows what's behind each door and always opens a door for a goat. This is therefore not random behavior.

    It's confusing at first, but read the Wikipedia article thoroughly and you'll understand.

    iŽll save you some time, this is the relevant passage:
    Using the switching strategy, winning or losing thus only depends on whether the contestant has initially chosen a goat (2/3 probability) or the car (1/3 probability). The fact that the host subsequently reveals a goat in one of the unchosen doors changes nothing about the initial probability.

  7. #7
    tulip's Avatar
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    OK, I thought I was right, then I thought I was thick, now I see just how counter-intuitive it is.
    Quote Originally Posted by Tarminic View Post
    Just for the record, "sending a needy text" is never the right answer.

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    The thought that made me finally get it back in the day was imagining 10k doors or whatever in the beginning. You pick a door, host opens all doors except the one you picked and one other. Would you switch or not? (obviously yes, same with three doors just a lot less obvious)

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    Dee Jiensai's Avatar
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    Thats easy, but a bit sad, but a story much repeated over history.
    See, they were a group rebelling against the establishment in the 70s and became so successful that they slipped into *being* the establishment.
    Leading to some prominent figures even supporting Brexit, while actually living abroad due to tax reasons.

    Wait
    Sorry, thats the MontyPython problem..
    never mind.

  10. #10
    King of the Babe Thread Donor Jolin's Avatar
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    I'm impressed the forum is still alive. Also hello!

  11. #11
    Dee Jiensai's Avatar
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    Quote Originally Posted by Jolin View Post
    I'm impressed the forum is still alive. Also hello!
    It's weird, isn't it?

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    Quote Originally Posted by Jolin View Post
    I'm impressed the forum is still alive. Also hello!
    Hello there!

    There are a couple of us who won't let it die. And honestly, although the contributions have dried out, all in all it's very civilized and insightful.

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    Dorvil Barranis's Avatar
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    Quote Originally Posted by Jolin View Post
    I'm impressed the forum is still alive. Also hello!
    Is it though?
    "Those who are skilled in combat do not become angered, those who are skilled at winning do not become afraid. Thus the wise win before they fight, while the ignorant fight to win." - Zhuge Liang


  14. #14
    Mashie Saldana's Avatar
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    Quote Originally Posted by Dorvil Barranis View Post
    Quote Originally Posted by Jolin View Post
    I'm impressed the forum is still alive. Also hello!
    Is it though?
    You can't kill what is already dead.
    When nothing goes right, go left.

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    i'm still around, FHC lives confirmed.

  16. #16
    Movember '12 Best Facial Hair Movember 2012Donor Lallante's Avatar
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    Quote Originally Posted by epictetus View Post
    The thought that made me finally get it back in the day was imagining 10k doors or whatever in the beginning. You pick a door, host opens all doors except the one you picked and one other. Would you switch or not? (obviously yes, same with three doors just a lot less obvious)
    Thats a great way of explaining it

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    Quote Originally Posted by Jolin View Post
    I'm impressed the forum is still alive. Also hello!
    Alive and kickin' you might say. Just noticed this gem from the forum's start page:

    Most users ever online was 7,557, August 3 2023 at 07:35:22 PM.
    The spam bots held their annual meeting here that day, I guess.

  18. #18

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    Quote Originally Posted by Hel OWeen View Post
    Quote Originally Posted by Jolin View Post
    I'm impressed the forum is still alive. Also hello!
    Alive and kickin' you might say. Just noticed this gem from the forum's start page:

    Most users ever online was 7,557, August 3 2023 at 07:35:22 PM.
    The spam bots held their annual meeting here that day, I guess.
    Nah, there's probably just a horde of us ancient lurkers, waiting for the day the drama llama awaken again...

  19. #19
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    Quote Originally Posted by Vicomt View Post
    Quote Originally Posted by Hel OWeen View Post
    Quote Originally Posted by Jolin View Post
    I'm impressed the forum is still alive. Also hello!
    Alive and kickin' you might say. Just noticed this gem from the forum's start page:

    Most users ever online was 7,557, August 3 2023 at 07:35:22 PM.
    The spam bots held their annual meeting here that day, I guess.
    Nah, there's probably just a horde of us ancient lurkers, waiting for the day the drama llama awaken again...
    I'm here for the games section and the Political threads!

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