Lottery odds

[georgie]

On another forum I frequent there's an interesting discussion going on about the odds of winning the lottery jackpot. Some one postulated that by buying a second ticket for the lottery you are doubling your chances of winning the jackpot.

Now I would have thought that was fairly obvious, however there are a hell of a lot of people who disagree. Are we more learned over here?

 

[megadave]

No seems like the obvious answer.

assuming the chances to win are 1 in 13,983,816 (think thats it for the uk) surely buying two just means 2 in 13,983,816?

actually im confused now, since that is twice as likely

 

[Zenith.UK]

Statistically yes.
1 in 14million ticket + 1 in 14million ticket = 2 in 14million = 1 in 7million.
You're halving the odds, doubling your chance.

This is why it is *possible* to bait the system if the rollover jackpot makes it worth it. If you print out all 14million combinations and *somehow* got them pushed through machines, you are guaranteed a win, or at least a share in the win.

 

[ileks]

I would have thought so Assuming you change at least one of the numbers you select obviously.

Why would people not think this is the case? I ask because doing a small amount of probability has taught me my instinct is usually wrong Like if you have 23 people (say on a football pitch) then there is around a 50% chance that two people share a birthday. This confused the hell out of me until I saw an explanation.

 

[Sparx]

Id say no, im no expert in maths but if it was that simple then everyone would be buying 2 tickets (which of course would then cancel out your extra ticket thus still the same odds)

 

[old.Tohtori]

Yes, when one vs two tickets are at play. After that it becomes a bit tricky.

Take 10 tickets, one winning, for example you buy 1.

You have a 10% of finding the one winning ticket.

You buy two, you double chances to 20%.

But if you buy three, your odds go up by 50%(of previous 20%).

So for each amount of tickets, you need to double your ticket amount to double your chances.

 

[ST^]

Since you said "a second ticket", you mean to say that you only had one in the first place, so yes, two tickets = twice as likely to win (unless you're a fucking tool who picked the same numbers twice).

 

[Zenith.UK]

I was thinking about this earlier this morning.
If you're in a syndicate, you get a share of the win.
What if you bought a line for yourself that is the same as one in the syndicate?
Now that line comes up.
The win is supposed to be split evenly between the winners.
Syndicate gets 50%. YOU get 50%.
Strictly speaking, you get your half of the win + your share in the syndicate's win.
You wouldn't be popular with the rest of the syndicate.

 

[ST^]

You don't have to tell them. They already know you've come into some money so you wouldn't have to explain your new purchasing habits

 

[ST^]

And on that point, who in their right mind would go public with the win? I would try to make sure as few people as possible hear about it.

 

[Lamp]

bit obvious if you're the flash your money type: 1 day your driving your scruffy 10 year old car, worrying about where you're gonna make the next buck; next day you're driving around in a £400,000 Lambourghini

 

[Genedril]

Of course you're doubling your chances but 1 in 7mil still isn't good odds. It's not much better than the odds of being hit by lightning twice.

 

[old.Tohtori]

Of course you're doubling your chances but 1 in 7mil still isn't good odds. It's not much better than the odds of being hit by lightning twice.

Then again, most every week someone wins. It's an old sayibng "it could be you", but it's true. Anyone of us, any week, could get that one break.

 

[Genedril]

Then again, most every week someone wins. It's an old sayibng "it could be you", but it's true. Anyone of us, any week, could get that one break.

Indeed, but then again this week it might be no one and the week after as well.

 

[old.Tohtori]

Indeed, but then again this week it might be no one and the week after as well.

True, true. It could go on for a year, even if not plausible, that no one wins.

I think of lottery as the name suggest; i throw less then a euro every week into it to say "Yes, i too would like to have a million."

 

[ST^]

I recently read a story in the paper that a Texas woman won over a million ... on 4 different occasions!

 

[Thorwyn]

Buying more than one ticket increases your chances. And in the case from one to two tickets, it doubles your chances.

 

[Influenza]

I recently read a story in the paper that a Texas woman won over a million ... on 4 different occasions!

Yeh i read that the other day , like 4 million 6 million twice and 8 million i think.

Its different in america though , if you win they offer you a one-off payment that is less than you won or you can get x amount every year and you get the full prize over like 10-20 years.

 

[Bahumat]

I am not the best with Maths, but saying this seems wrong;
assuming the chances to win are 1 in 13,983,816 (think thats it for the uk) surely buying two just means 2 in 13,983,816? actually im confused now, since that is twice as likely

This is what I think;
1 ticket = (ease of explanation) a 1 in 14,000,000 chance of winning.
2 tickets = a 1 in 13,999,999 chance of winning

So for each additional ticket you purchase, the total number is reduced by 1.

e.g. 10 tickets = 1 in 13,999,990 chance to win.

With that in mind, you don't fall into the 2 in 14,000,000 chances aka "oh it's doubled my odds".

 

[old.Tohtori]

That's not how it works though Bahu.

You see it better when you scale it down(10 tickets, 100 tickets etc).

Even with 1 million tickets, you've got a 0.0001 chance to win, with 2 tickets you got 0.0002 chance.

Doubled chances, but with third ticket it's a minimal increase.

 

[Sparx]

But that will only be if the number of ticket sales stays the same. If everyone bought 2 tickets to double their odds then double the amount of tickets have been sold from the original figure

 

[old.Tohtori]

But that will only be if the number of ticket sales stays the same. If everyone bought 2 tickets to double their odds then double the amount of tickets have been sold from the original figure

Yes, but 1 ticket vs 2 tickets difference stays the same no matter what.

2 tickets vs 1 ticket, at start, is double chances.

Even if there's only 3 tickets, two tickets have double chances vs the 1 ticket.

the chances in lottery are still very very VERY small, but still double. Like adding 2 grains of sand to beach instead of 1.

 

[Sparx]

Im just not getting it, i dont think its that simple

 

[Sparx]

Or what if no-one gets 2 tickets but you

1000 tickets are sold so you get a second ticket that means 1001 tickets are sold. So doesnt that mean its not a true double chance?

 

[ST^]

But that will only be if the number of ticket sales stays the same. If everyone bought 2 tickets to double their odds then double the amount of tickets have been sold from the original figure

The chance of winning isn't based on how many tickets are bought overall. If you bought the only ticket in the world, you still have the same chance of winning as if 5 billion tickets were sold.

 

[Vae]

Or what if no-one gets 2 tickets but you

1000 tickets are sold so you get a second ticket that means 1001 tickets are sold. So doesnt that mean its not a true double chance?

If it were a raffle then that would be the case but it's not. It's a lottery where the odds of choosing the right numbers are about 14m to 1 regardless of how many tickets are sold. The only thing the tickets affect is the prize amount.

 

[Sparx]

Yeah i suppose

 

[Genedril]

The chance of winning isn't based on how many tickets are bought overall. If you bought the only ticket in the world, you still have the same chance of winning as if 5 billion tickets were sold.

That - but there's then a higher likelyhood that the jackpot would be shared. That's a different arguement though.

 

[Cyradix]

A while back some guy on tv calculated that the chance of being hit by lightning while on your way to the store to buy your ticket is 3x the chance of actually winning...

 

[Garaen]

If you said no please do the world a favour and go and walk in front of a speeding train or alternatively head to the local primary school and take a maths lesson from a few 4 year olds.