tag:blogger.com,1999:blog-3972382144120426476.post3394909824397221202..comments2020-09-26T10:03:44.296-05:00Comments on Every goddamn day: 09/26/20: The Monty Hall ProblemNeil Steinberghttp://www.blogger.com/profile/11468057838260476480noreply@blogger.comBlogger21125tag:blogger.com,1999:blog-3972382144120426476.post-10815380835363137742017-10-05T06:07:30.919-05:002017-10-05T06:07:30.919-05:00There are three doors. The thing to remember is th...There are three doors. The thing to remember is that Monty always opens a donkey door. The result is that if you switch, you are picking TWO doors--the one that you end up with and the donkey Monty reveals. Thus your chance of a car is 2/3. If you don't switch, you only get the door you actually selected.Carlhttps://www.blogger.com/profile/08674198657010416085noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-87071670006949079842017-10-04T13:59:08.486-05:002017-10-04T13:59:08.486-05:00Eric -- Exactly. Showing what's behind the thi...Eric -- Exactly. Showing what's behind the third door doesn't affect the odds of your initial pick being correct, which remain one in three. What they do is double the odds of your second pick being correct, by eliminating possibilities. As for the odds of us both picking a relatively obscure subject, those numbers I can't fathom.Neil Steinberghttps://www.blogger.com/profile/11468057838260476480noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-54033806159500173132017-10-04T12:39:30.720-05:002017-10-04T12:39:30.720-05:00155? Wow. One tenth of one percent of the populati...155? Wow. One tenth of one percent of the population is over 145. You'd think he wouldn't have cognitive deficiencies. Maybe he meant 115. That'd put him at the high end of normal.Tony Galatihttps://www.blogger.com/profile/11944671504245191140noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-18488550956268170272017-10-04T12:09:59.910-05:002017-10-04T12:09:59.910-05:00Now... what were the odds that Neil and I would bo...Now... what were the odds that Neil and I would both eschew feckless pontificating about Las Vegas to ruminate on the Monty Hall problem? I gave him a shoutout in my newsletter http://e.chicagotribune.com/a/hBZ1RO4B8hLfLB831YEAAA9U7Kn/chi3-2 -- and while I'm at it, here's something I just wrote to a guy who boasted an IQ of 155 and told me I was full of shi on this matter:<br /> <br /> imagine a five-card game. There's one black card and four red cards, all face down. The black card is the winner. You pick one of the cards but don't look at it.<br /><br />What are the odds that you have selected the winning card? 1 in 5, right?<br /><br />And what are the odds that one of the other four cards is black ? 4 in 5, right?<br /><br />I randomly and with no knowledge of the outcome turn over just one of the other four cards, which remain in front of me. It's red. Have your odds of winning the game improved? Are they now one in four?<br /><br />If you think so, then you need a basic course in probability. Of course they have not!!! They are 1 in 5. Always, always 1 in 5.<br /><br />I turn over another card. It's also red. Have your odds of winning the game NOW improved?<br /><br />No, they remain 1 in 5, always, always 1 in 5.<br /><br />It doesn't matter how or why I'm turning over the red cards. Maybe I know where the black card is, maybe I don't. But even if I turn over one more card and it's red, the odds that your card is the black card REMAIN 1 in 5.<br /><br />So should it come down to one of my original four cards and the one card you selected, what are the odds that your card is black? Repeat after me... 1 in 5... always, always 1 in 5.<br /><br />And the odds that the remaining card from my original set is black? 4 in 5. Definitely, obviously, provably, always 1 in 5.<br /><br />Play this game yourself if you're not satisfied. Over time, you will lose 80 percent of the time if you don't switch at the end when it comes down to two cards.<br /> Eric Zornhttps://www.blogger.com/profile/13198559520854637027noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-77201336226207149602017-10-04T00:21:39.206-05:002017-10-04T00:21:39.206-05:00Did you use a program to get this or just write it...Did you use a program to get this or just write it down? Not disagreeing just wondering how you got it.<br /><br />And where is the Burro?Molexhttps://www.blogger.com/profile/12525209445108180081noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-29116416621759998732017-10-04T00:06:48.025-05:002017-10-04T00:06:48.025-05:00I talked about your math and had a very cognoscent...I talked about your math and had a very cognoscente remark from a friend of mine. He said he wanted the Burro. We laughed a bit and then I thought of the taxes, insurance and every thing else involved with the car. I realize there are costs with the burro too, but I already have a car and 2 motorcycles, but I have no burro. I think I would stick. Molexhttps://www.blogger.com/profile/12525209445108180081noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-7074684288330404322017-10-03T16:37:03.001-05:002017-10-03T16:37:03.001-05:00I see Eric Zorn has written a column on this subje...I see Eric Zorn has written a column on this subject:<br /><br />http://www.chicagotribune.com/news/opinion/zorn/ct-perspec-zorn-monty-hall-problem-1004-20171003-story.htmlAnonymoushttps://www.blogger.com/profile/04541828632284556589noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-85541892755093147072017-10-03T13:25:39.763-05:002017-10-03T13:25:39.763-05:00That's remarkable. You should play the lottery...That's remarkable. You should play the lottery today.Tony Galatihttps://www.blogger.com/profile/11944671504245191140noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-7529254529030899912017-10-03T12:52:38.799-05:002017-10-03T12:52:38.799-05:00OK, I played 20 hands of three-card Monty after lu...OK, I played 20 hands of three-card Monty after lunch, and FWIW, here were my results:<br /><br />No switch: Car 7, donkey 3<br />Switch: Car 4, donkey 6Bitter Scribehttps://www.blogger.com/profile/04645909858616987997noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-38070455258987529802017-10-03T10:04:16.178-05:002017-10-03T10:04:16.178-05:00OK, OK, I surrender to the math gods. That Monty H...OK, OK, I surrender to the math gods. That Monty Hall was a tricky little devil.<br />SandyKnoreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-80726105398995145332017-10-03T09:48:17.633-05:002017-10-03T09:48:17.633-05:00Hmmmm...OK, now I'm starting to see it. Thanks...Hmmmm...OK, now I'm starting to see it. Thanks, Unknown.<br /><br />(So I snuck back here from work. Sue me.)Bitter Scribehttps://www.blogger.com/profile/04645909858616987997noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-55791709019455764602017-10-03T09:37:36.177-05:002017-10-03T09:37:36.177-05:00I'm getting a headache.I'm getting a headache.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-8123798398070947522017-10-03T09:32:23.645-05:002017-10-03T09:32:23.645-05:00This comment has been removed by the author.Unknownhttps://www.blogger.com/profile/06478738678540552126noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-20685581719470626962017-10-03T09:19:48.917-05:002017-10-03T09:19:48.917-05:00Sorry, been thinking about this for several minute...Sorry, been thinking about this for several minutes (all I have time for this morning) and still not seeing it.<br /><br />BTW, speaking of unfavorable odds, that Sanskrit online gambling spam has popped up in the previous thread.Bitter Scribehttps://www.blogger.com/profile/04645909858616987997noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-44583951052891733432017-10-03T08:52:36.702-05:002017-10-03T08:52:36.702-05:00Fascinating. To many people the correct answer is...Fascinating. To many people the correct answer is absurd and no matter how many ways you approach it (a pack of cards whittled down to 2 is my favorite gambit), they fail to grasp the concept. Just like those who refuse to see that the very presence of so many guns in our society is pernicious and needs no evil-minded maniacal villain to blame.<br /><br />johntatehttps://www.blogger.com/profile/10088632798195131329noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-81195704530067508322017-10-03T08:33:10.158-05:002017-10-03T08:33:10.158-05:00I knew it, within the great unknown there are norm...I knew it, within the great unknown there are normal people. When I read Marilyn's column in Parade it didn't make sense. So I started writing a Pascal program to simulate the problem using the Monty Carlo method. The same solution you provide became obvious as correct, Marilyn was right. Now we can hypothesize an alternate universe with an Evil Monty Hall. He would only make the offer when the contestant made the right choice. In fact he would have all manner of tricks and traps to turn all contestants into losers, no matter what choices they made. Soon the ratings would grow as he gained an audience of sadistic fans. And similar behavior would spread all over. Not a happy place, thank goodness we live in a good universe, at least I hope so.Berniehttps://www.blogger.com/profile/17157600812959885192noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-6339976722182548322017-10-03T07:15:46.522-05:002017-10-03T07:15:46.522-05:00This comment has been removed by the author.Unknownhttps://www.blogger.com/profile/06478738678540552126noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-53374934151398089692017-10-03T07:02:52.791-05:002017-10-03T07:02:52.791-05:00I understand the two out of three (you're give...I understand the two out of three (you're given two choices), but that final choice is still a coin toss. Like Sandy, I'd like to see the data supporting this theory.Anonymoushttps://www.blogger.com/profile/04541828632284556589noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-71149899414217213302017-10-03T03:56:50.435-05:002017-10-03T03:56:50.435-05:00I'm just wondering, that when Monty Hall's...I'm just wondering, that when Monty Hall's friends & family got to the undertakers, were they told to pick from chapel #1, chapel #2 or chapel #3 & did they get a zonk if they picked the wrong chapel?Clark St.https://www.blogger.com/profile/09634234069783123180noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-18248087408377982012017-10-03T03:47:54.222-05:002017-10-03T03:47:54.222-05:00That's interesting. In other words, odds are p...That's interesting. In other words, odds are pretty good that your initial pick was wrong. Why get stuck with what was probably the wrong choice.<br />What I don't understand is what any of this has to do with the picture at the top of the Vietnam Women's Memorial.Tony Galatihttps://www.blogger.com/profile/11944671504245191140noreply@blogger.comtag:blogger.com,1999:blog-3972382144120426476.post-55357691460343813862017-10-03T00:45:19.788-05:002017-10-03T00:45:19.788-05:00I remember seeing this in the Parade magazine a lo...I remember seeing this in the Parade magazine a long time ago, and after thinking on it I still believe there's a flaw in Ms. von Savant's reasoning. <br /><br />The nagging problem I have with this is: The original odds were 1 chance in 3 to get the car. Say I picked Door #1, then find out Door #2 has a donkey behind it. The fact that Door #2 has a donkey behind it doesn't PHYSICALLY move the car to another door. So, tell me again why I should switch? The odds after the donkey is revealed in Door #2 are still 50/50 between my original pick (Door #1) and the other door (Door #3). Was this theory proven to be correct on the show?SandyKnoreply@blogger.com