Fela
Joined: Dec 27, 2004
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  Posted:
Apr 20, 2011 - 17:53 |
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PurpleChest wrote: |
one factor so far missing from this puzzle is the knowledge of the person showing you the empty cup. If they KNEW it was empty and showed you it follows the rules above, and you should switch.
If it is a blind draw that just happens to produce a no pea result (the chooser had a 33% of picking the pea and showing you it), the odds are then 50-50. |
If it's a blind draw, the choser may have 33% , but if he gets the cup with the pea, the game ends and you won't be able to chose. Therefore, IF he shows you an empty cup, the puzzle remains the same and you'd have to swap to increase your chance from 33% to 66%.#
The example is still invalid, because everyone knows the chance for the pea being under any cup before it's actually shown under the one you did NOT chose is precisely 0. |
Last edited by Fela on %b %20, %2011 - %17:%Apr; edited 1 time in total |
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Mr_Foulscumm
Joined: Mar 05, 2005
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  Posted:
Apr 20, 2011 - 17:53 |
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How dare Christer defend HIS scheduler on HIS site? The outrage! |
_________________ Everybody's favorite coach on FUMBBL |
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Purplegoo
Joined: Mar 23, 2006
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  Posted:
Apr 20, 2011 - 18:08 |
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Is this.... Really still going...? |
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Mr_Foulscumm
Joined: Mar 05, 2005
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  Posted:
Apr 20, 2011 - 18:10 |
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Purplegoo wrote: | Is this.... Really still going...? |
Indeed it is |
_________________ Everybody's favorite coach on FUMBBL |
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freak_in_a_frock
Joined: Aug 02, 2003
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  Posted:
Apr 20, 2011 - 18:12 |
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I blame the lack of a poll. |
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Macavity
Joined: Nov 23, 2004
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  Posted:
Apr 20, 2011 - 18:25 |
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I blame Macavity! |
_________________ When I became a man I put away childish things, including the fear of childishness and the desire to be very grown up. -C.S. Lewis |
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Timlagor
Joined: Feb 13, 2009
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  Posted:
Apr 20, 2011 - 18:43 |
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licker wrote: | It might be the only thing which can beat ClawPOMB...
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You forget! FEND beats ClawPOMB
(must be true the designers said so!) |
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PurpleChest
Joined: Oct 25, 2003
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Fela wrote: | PurpleChest wrote: |
one factor so far missing from this puzzle is the knowledge of the person showing you the empty cup. If they KNEW it was empty and showed you it follows the rules above, and you should switch.
If it is a blind draw that just happens to produce a no pea result (the chooser had a 33% of picking the pea and showing you it), the odds are then 50-50. |
If it's a blind draw, the choser may have 33% , but if he gets the cup with the pea, the game ends and you won't be able to chose. Therefore, IF he shows you an empty cup, the puzzle remains the same and you'd have to swap to increase your chance from 33% to 66%.#
The example is still invalid, because everyone knows the chance for the pea being under any cup before it's actually shown under the one you did NOT chose is precisely 0. |
nope. as long as there is a 33% chance that the 'host' lifting a cup shows you the pea, the 2 left still have 50% odds. even if it didn't show you a pea. only if the one he shows you he KNOWS has no pea do the odds become better for the remaining cup.
And yet of course you are right, the pea/ball is in his hand and re-appears at will where he wants it, and you feel a fool for falling for the oldest trick in the world ever. |
_________________ Barbarus hic ego sum, quia non intelligor illis -Ovid
I am a barbarian here because i am not understood by anyone |
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pythrr
Joined: Mar 07, 2006
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  Posted:
Apr 20, 2011 - 20:22 |
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Macavity wrote: | I blame Macavity! |
I blame people who obsessively do math.
Ban MATH! |
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f_alk
Joined: Sep 30, 2005
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  Posted:
Apr 20, 2011 - 20:35 |
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pythrr wrote: | Dude, sorry to break it to you, but this is not a democracy. |
Of course it is not - but in autocratic regimes smart dictators also listen to their people if they want their lands to grow and blossom.
Astarael wrote: | There needs to be an implemented bias against mirror matches, otherwise it's prejudiced towards them. ... some people seem to still be acting like they think it's to avoid mirror matches. It's not, it's to avoid the natural bias towards them. |
If the algorithm was stripped down to a pure "minimize the TV differences", then there wouldn't be a bias towards or against mirror matches.
The bias towards mirror matches is an artefact from other parts of the algorithm, so this bias is as natural as it's cure: not at all. |
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licker
Joined: Jul 10, 2009
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  Posted:
Apr 20, 2011 - 21:09 |
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PurpleChest wrote: |
nope. as long as there is a 33% chance that the 'host' lifting a cup shows you the pea, the 2 left still have 50% odds. even if it didn't show you a pea. only if the one he shows you he KNOWS has no pea do the odds become better for the remaining cup.
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I don't think you're right, but the premise is so bizarre that I find myself not caring either.
the guy says 'here pick one of these three' then he shows you one that has the pea in it and says... you lose!
errr... what's the point of him randomly opening one again? It makes no sense.
[and it doesn't change the probability either, still 33% that you were right the first time, you cannot change that to 50% unless he remixes the samples afterwards] |
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Macavity
Joined: Nov 23, 2004
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  Posted:
Apr 20, 2011 - 21:10 |
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Licker, don't argue. It intuitively makes no sense, but does work. It's a higher math silliness thing, but true in the real world, assume you had no other reason to choose one over the other (watching them mix it up, for instance). |
_________________ When I became a man I put away childish things, including the fear of childishness and the desire to be very grown up. -C.S. Lewis |
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Unstoffe
Joined: Aug 22, 2004
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  Posted:
Apr 20, 2011 - 21:13 |
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pythrr wrote: | Macavity wrote: | I blame Macavity! |
I blame people who obsessively do math.
Ban MATH! |
But it's such fun! Whether you carry the plural into your abbreviation or not!
(As a speaker of British English, I sure ain't going to criticise anybody for irregularities in their language - long live irregularities )
Oh, and the Monty Hall problem is kind of a cheat... the rule that the host must always lift a cup / open a door tends not to be mentioned, if it were a smart listener would go 'hmm, that isn't how I'd expect him to behave'. |
_________________ British or thereabouts? Check out the White Isle League |
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licker
Joined: Jul 10, 2009
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  Posted:
Apr 20, 2011 - 21:13 |
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How am I supposed to assume I have no reason to chose one over the other when I obviously do? |
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Reisender
Joined: Sep 29, 2007
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  Posted:
Apr 20, 2011 - 21:19 |
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pythrr wrote: |
Dude, sorry to break it to you, but this is not a democracy. |
*facepalm |
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