To think this is not how raffles work?

[PopcornAndPizza]

Hotly contested discussion at work and although light-hearted I now think I'm either losing the plot or almost all my work colleagues are all weird.

A colleague was pleased yesterday that she had won a coffee voucher at her grandsons school raffle. She mentioned her prize was the 8th top prize and that unfortunately her ticket didn't win any more prizes after that including the top prize which was a tablet.

I was only half paying attention until the other colleague (that I think is right) then said well surely they announced that one first? To which she replied well no they did that one last to build suspense.

To help the other colleague I tried to point out that's not how it works because then your ticket isn't actually in with the chance of winning the top prize but only me and this one other lady had this viewpoint, everyone else couldn't see the issue.

It's not us is it, that's not how raffles work? Surely the top prize should be drawn first so everyone has an equal chance at winning?

Yes I was thinking of those draws where you win a prize, then if another of your tickets is drawn you feel you should decline. If the prizes were allocated from lowest to highest, why would you decline the next one you win? Someone could theoretically win (and take) all of them, which I know is possible the other way round but you just wouldn’t 😂 . You could swap in a lower when you win a higher but what a faff! Anyway I never win anything, although I did once win 100 pints of beer - one per day at a local pub. Never had a single one! Wonder why I entered (competition in local paper)?

I remember a thread where the OP had won multiple prizes, and after the third (I think?) time, the draw-er took it upon herself to put the ticket back and choose another, to give someone else a chance. OP was furious. Don't remember the outcome of that one, either...

At our school raffle there were 20 prizes. Each prize had a number 1 to 20. They werent in order of size or value. Just random order. Tickets were drew and first ticket got prize number 1 and 2nd ticket drawn got prize number 2 and so on. There wasnt a 'top' prize, just different prizes. Although the prjzes really varied in value.

Exactly - as each ticket is drawn the odds change.

If your ticket is pulled, then you have 0 chance the next draw
If your ticket is not pulled, then you have a minutely better chance the next draw

I've never thought about this before, but it's quite fascinating!
I can only say that I agree with OP. They could still have the suspense side of it if they drew the winning ticket first, but still read it out last?

First out the hat should win the biggest or best prize obviously.

This would be much fairer and still keep the suspense element. I think it's a really good compromise.

I agree.

This is proper maths and statistics and psychology and everything all bundled into one thread.

My instinct tells me that the OP is wrong. Her ticket had every chance to win the top prize. It had the same chance as every other ticket in the draw to not be picked earlier in the draw. It just happened - by chance - to be picked before the top prize. I don't think that makes the draw unfair.

But I genuinely think this is one for the maths professors.

Why?

As long as all of the tickets are sold before the draw starts, why does it matter?
You have a 1 in 500 chance of winning the car.

Surely the only thing that's different (I think, not a statistician) is the "gaming" aspect of the raffle. You miss out on the repeated buzz that you might win the car if you are drawn early but your actual chances of winning the car are not affected.

The key thing with any competition is that the rules are laid out in advance, if you plan to rank the prizes and draw in reverse order that is legal as long as you have told people when they purchased them.

They could make a bit of a fuss of it, like, 'we're drawing the winning ticket now, and we are putting it in this empty gold box. Then once we draw the other prizes, the lucky big prize winner will be announced' and draw it from this fancy box with a drum roll or something.

I get annoyed if you buy a strip of five tickets and the organisers don’t separate the tickets into five separate numbers. If I only wanted one chance I would only buy one ticket, if I buy five tickets it’s because I am buying five chances. It happens more often than you think!

We had the unluckiest raffle tickets ever a few weeks ago, three prizes went to anagrams of our ticket numbers, another prize went to a ticket in the preceding strip, then blow me down, the man sitting next to us ( who to be fair had very different tickets) only went and won the top prize. The raffle fairies were not playing nice that evening, for us anyway , though we were really relieved we didn’t win one prize which would have meant travelling to the furthest reaches of the country to take part ( no mention of travel costs/ accommodations were made)🙂

But you haven’t got a one in five hundred chance of winning the car if your ticket isn’t in the hat because you’ve won the haribo. You have no chance of winning it.

On the first draw its a 1 in 500 (you have 1 ticket)

if you win a prize on the first draw - you now have 0 / 499
if you dont win you have a 1 / 499

if you win a prize on the next draw - you now have 0 / 498
if you dont win you have a 1 / 498

if you win a prize on the next draw - you now have 0 / 497
if you dont win you have a 1 / 497

if you win a prize on the next draw - you now have 0 / 496
if you dont win you have a 1 / 496

if you win a prize on the next draw - you now have 0 / 495
if you dont win you have a 1 / 495

etc

Sounds like a tomblola rather than a raffle

But that wouldn’t change your odds. You still have a 1/500 chance of winning, the order the tickets are drawn makes no difference

You do at the beginning of the process.

it starts with 500 equal chances and ends with 1 random winner. The order makes no difference

I think most raffles I've ever seen have started with the smaller prizes and ended on a flourish with the top prize.

I'm just giving my experience of raffles

It's not 1 in 500. You need to factor in the probability of your ticket being one of the 499 that will be removed before the car prize is drawn.

So round 1, your probability of being taken out is 1/500. Then round 2, it's 1/499. Round 3 1/498. You'd have to do some fairly complex maths to work out your actual probability of a) remaining in the draw when the car is drawn, and b) being the winning ticket.

On the first draw its a 1 in 500 (you have 1 ticket)

@Shnuzzbucket that's not quite right if the car is drawn at the end - see my previous post.

I'm pretty sure no-one ever announces which order prizes will be drawn in!

Sorry my posts just then might not be right as assumed no-one would actually draw 499/500 tickets as losing ones! So I think I've confused myself there

If you had 500 tickets and took 20 out to win small prizes, then the big prize was picked from the remaining 480, that would be a different calculation of odds for the big prize than 1/500... or would it? I need someone to explain to me now - any statisticians?!

It's not about probability, if you buy a ticket for a chance to win the big prize the only question on the day is "are you in the main prize draw?"

If your ticket has been drawn and won a minor prize then no you are not in the main prize draw - to misquote Monty Python "What you 'ave 'ere is a deceased ticket, sir".