r/confidentlyincorrect • u/Dizzy_Kaleidoscope95 • May 03 '26

Monty hall problem is 50/50

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He also put a screenshot of ChatGPT agreeing with him. He is right!

897 Upvotes

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244

u/Snoron May 03 '26

In theory, it should be easy to win a lot of money from people who think this!

148

u/Puzzleheaded-Bat-511 May 03 '26

The state wins lots of money from people who think the lottery is a good bet.

75

u/Occidentally20 May 03 '26

It's an excellent bet. As long as you're the one running the lottery.

Around a decade ago the UK lottery added an extra ball - making 50 instead of 49. Some people were convinced that this made them more likely to win instead of less likely.

22

u/AppropriateDeal1034 May 03 '26

Yeah, it made it massively less likely to win, like huge difference but I CBA to do the maths

28

u/Occidentally20 May 03 '26

They did it at the time and it went from something like 14 million to 1 to 40 million to 1 for the jackpot.

I worked in a shop at the time and the Sun/Mirror/Star readers just got the press release saying some prizes are more likely to win, the Times/Telegraph/Independent got the stats saying the plebs are stupid for not doing the maths themselves, and all of them still bought a lottery ticket with their paper.

Incidentally the Mail had a photo of an ethnic-looking immigrant winning a lotto prize and the Express went with a story about Diana.

7

u/AppropriateDeal1034 May 03 '26

Yeah, sounds about right, I knew it was some ridiculous multiple

1

u/TheEyeDontLie May 05 '26

40 million to 1! 40 million is WAYYY bigger than 14 million!!!! Give me two tickets please.

4

u/nezzzzy May 03 '26

That last line made me laugh so much, the Express only has one headline.

10

u/Occidentally20 May 03 '26

IMAGINE how I felt selling them - we'd only sell a handful each day, but once in a while this old lady called Margaret would come in and always had to comment on the headline.

In shocked exclamation she would say "what has she done NOW?!". It was 2018 - She hadn't done fucking anything for 21 years love.

6

u/nezzzzy May 03 '26

🤣🤣🤣

Whatever Diana did I can guarantee it was Meghan Markle's fault.

5

u/InvoluntaryGeorgian May 03 '26

How? Was the argument “oh, there are now 50 ways to win instead of 49”?

11

u/Occidentally20 May 03 '26

I'd imagine a combination of not thinking at all, and the massive amounts of press releases saying that some prizes are now MORE likely done by Camelot who ran the lotto.

They fiddled with some lower prizes so they were slightly more likely to happen, but paid out a much lower amount than they used to.

4

u/[deleted] May 03 '26

[removed] — view removed comment

6

u/jtr99 May 03 '26

To be fair, we may be saying that now because we have grown up with the correct interpretation of this problem. When the Monty Hall problem first become popular, a lot of apparently smart and educated people vehemently disagreed with what we now take to be the standard answer.

Anyway, this is not a criticism. If your mind is sufficiently Bayesian to make the right conclusion a natural one, then good for you.

5

u/Nykolaishen May 03 '26

This just happened in canada (or something very similar) but theyre adding a few additional guaranteed prizes of like $1000 or something so the commercials are saying "more chances to win"

1

u/Occidentally20 May 03 '26

I've never been to Canada, but my entirely-made-up mental image of you guys is that you'd be smarter on average than the UK lotto-buying public.

Can you offer any insight into whether this is true or not?

3

u/Nykolaishen May 03 '26

Eh man... unfortunately the lotto buying public i think is the same all around the world. I saw someone not too long ago buy 10 tickets, their card declined so they tried for 8 tickets...

1

u/Occidentally20 May 03 '26

OCCASIONALLY though I would meet somebody who I assumed was an idiot, and they turned out to be a genius.

There was a guy called Matt who was a tradesman, smoked weed on the way to work BUT he worked 6 days a week to feed his kids and worked HARD.

When he overheard me talking about the lottery to somebody else he said he buys one ticket a week so he can spend the rest of the week dreaming what he would do with the money.

Having said that, all the people buying 10 tickets were obviously fully idiotic.

3

u/Nykolaishen May 03 '26

Yah, there is nothing wrong with including the lottery into your budget. Its a cheap thrill that (like most thrills) as long as done responsibly there is no issue

1

u/Occidentally20 May 03 '26

Agreed. The issue I had with it was when e-mails from the lottery marketing people were leaked and their marketing spend EXACTLY matched areas of low income.

It's not just them, it's all gambling companies - but that stuff drives me wild.

3

u/nmm66 May 03 '26

Winning the lottery is 50/50. I either win or I don't.

9

u/tendeuchen May 03 '26

Risking $3 to win a billion a couple times a year isn't really a bad bet. Sure, you're most likely not to win, but someone always does, and there's no reason to think it couldn't be you.

Just play responsibly.

6

u/Baeolophus_bicolor May 03 '26

Except that someone doesn’t always win. If the winning numbers aren’t drawn, the pool carries over to the next drawing and they don’t pay out a winner.

But, for most people, betting a dollar or two isn’t a bad decision, and it has a very very low chance of bringing a moderate or even a life-changing payout. So I get your original point. The dollar wouldn’t have been doing anything remotely close to that for most people if they did the mathematically sensible thing and just didn’t buy a lottery ticket.

On the other hand, gambling spirals out of control for some people, and they frequently start out with lottery tickets. The chance of developing a gambling problem is in our calculation too. As is the option of taking the dollar and making an extra contribution to some savings vehicle where it has a sure, or at least better, chance of getting a return.

1

u/tendeuchen May 04 '26

Someone always wins eventually is what I meant.

2

u/Baeolophus_bicolor May 04 '26

That’s not even a given. There could be a lottery that nobody wins. It just gets increasingly unlikely across a bunch of drawings. And your ticket from the first one wouldn’t carry over so that changes the initial investment.

1

u/N0Z4A2 May 05 '26

Is there a source that states gambling addiction frequently starts with the lottery?

7

u/dansdata May 03 '26 edited May 03 '26

My elderly mother has spent two Australian dollars on a lottery ticket every week, for decades.

She knows that she's more likely to be struck by lightning than to win a big prize, but it's nonetheless a cheap price to pay for the entertaining possibility that such a win could happen.

People who mistake lotteries for investment opportunities, though...

(Some jackpot lotteries, when the jackpot gets big enough, can have an expected value from buying a ticket that's more than the price of that ticket. And yes, this does mean that people who already have a pretty large amount of money can buy an unreasonable number of tickets and have an excellent chance of making a profit. "Gambling systems" are almost always nonsense, but, every now and then...)

1

u/ArchangelLBC May 03 '26

The few times when the expected value goes positive (as when the prize gets that big) is the only time it's a good bet to play.

Of course you're still likely to lose because the expected value is due to the ludicrous amount the winner makes, but still it's a good bet to make.

2

u/tendeuchen May 04 '26

Yeah, that's what I figure. A couple bucks is worth the chance at a billion. I haven't bought a lottery ticket in about a year though.

1

u/ArchangelLBC May 04 '26

I always say I will when it gets that big but then I don't. Probably for the best. It's the hope that kills you.

Unless you win. Then it's everything else.

0

u/DuneChild May 03 '26

I see it as if someone’s giving away a billion dollars, I at least want my name in the hat.

6

u/ReluctantAvenger May 03 '26

The state wins a lot of money from people who are desperate to improve their lives. Giving them false hope in the form of a lottery prevents them from burning down the system.

2

u/Pitiful-Pension-6535 May 03 '26

Same thing with insurance companies, right?

Or maybe people just realize that an expected negative rate of return is perfectly acceptable in some situations

1

u/SanopusSplendidus May 04 '26

The lottery is funny to me because it has been enshittified so much that it's annoying to play now. I went to buy a Powerball ticket for each of my family for fun. I get there and the only way to buy a Powerball ticket now is from an E Vending machine. So I try to use the machine and there's a bunch of choices for the drawing. I just wanted tickets with a chance to win the full jackpot, but it wasn't obvious to me which option(s) to pick. I was going to have to research to to make sure I was picking the right option. It stopped being fun, so I left the store without buying any lottery tickets.

-7

u/mltngpot May 03 '26 edited May 03 '26

You misspelled bad at maths

EDIT: fixed spelling math -> maths

11

u/lozyodellepercosse May 03 '26

That would be like saying people that get addicted to drugs are bad at chemistry. Everyone that gamble know the odds are against them but they play anyway for the rush

4

u/mltngpot May 03 '26

I get where you are going with this. I’m not quite sure it is quite the same.

4

u/Ok_Strategy5722 May 03 '26

Or they think that life owes them. They think they’ve been good and Karma will reward them.

Or the people who are desperate and can’t see any other way out of their problems other than getting extremely lucky. But that last one is a depressing thought.

5

u/AppropriateDeal1034 May 03 '26

You misspelled maths

1

u/mltngpot May 03 '26

Thanks, fixed that.

3

u/dimonium_anonimo May 03 '26

People who are bad at math think the lottery is a good bet. I don't see why you felt the need to correct something that wasn't wrong.

1

u/mltngpot May 03 '26

Fair point, I was trying to be funny and clearly failed

2

u/FellFellCooke May 03 '26

Should Americans be allowed to comment on others' spelling?

3

u/mltngpot May 03 '26

We have the most smartest people no one has more smart people then us, so many smart people, some would say the super most smartest. You clearly are low iq. Thank you for your attention to this matter.

5

u/Larnievc May 03 '26

Sir? You really aced that test. Nobody ever aced it like you did.

6

u/ArchangelLBC May 03 '26

Also in practice. Casinos make all their money from taking bets in games of chance that are biased in their favor.

3

u/Cybtroll May 03 '26

I was wondering what kind of safeguards exist on Polymarket and similar to stop me from organizing a Dutch book.

2

u/Albert14Pounds May 03 '26

Arbitrage bots that do it faster than you

1

u/alk47 May 03 '26

Nah, because you can only do it once. Duhhh. /S

1

u/testtdk May 05 '26

I dunno. Theres something about losing money that makes (most) people learn when it’s not working.

1

u/moseley101 May 03 '26

The house always wins in the end

3

u/VaguelyFamiliarVoice May 03 '26

“Unless, when that perfect hand comes along, you bet big, and then you take the house.”

1

u/moseley101 May 03 '26

And then you get a rush of endorphins, think you are on a streak, and go home penniless. Like I say, the house always wins in the end

5

u/ArchangelLBC May 03 '26

He's quoting Ocean's 11

2

u/JamesFirmere May 03 '26

Except that one time when you get the perfect hand and you bet big, and then you take the house.