Bad run on Premium Bonds

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This thread makes me feel better about my bad luck so please don't post any positive winnings here. Use the other thread instead.

the_goon

As I posted on the other thread.. I have a max holding and have won zero for 5 draws in a row now.
December 2022 I won 2 x £25.
  

Albermarle

the_goon said:

As I posted on the other thread.. I have a max holding and have won zero for 5 draws in a row now.
December 2022 I won 2 x £25.
  

Working on the probability figures in previous posts, I have worked out that the chance of someone with the max holding, having no prizes 5 months in a row is about one in 60,000. Even if this figure is not exactly right you have been exceptionally unlucky.

the_goon

Albermarle said:

the_goon said:

As I posted on the other thread.. I have a max holding and have won zero for 5 draws in a row now.
December 2022 I won 2 x £25.
  

Working on the probability figures in previous posts, I have worked out that the chance of someone with the max holding, having no prizes 5 months in a row is about one in 60,000. Even if this figure is not exactly right you have been exceptionally unlucky.

At least I'm healthy. There are people way unluckier than me, I guess. (just not on premium bonds though) lol.

DarrenNorthEast

SpeedSouth said:

On  the flip side I deposited £30k in March, bringing it up to £38k total.  I won £375  in April and £200 (25+25+50+100) this month.

So I'm close to 2% for the tax year already on the new deposit.

I did the same, I bought £30,000 in January which first entered in March.
I then added another £8,000 in March to make it £38,000 entered in May.

March: £100
April: £25
May: £225 (£25, £100, £100)

eskbanker

JohnWinder said:

eskbanker said:

The odds of a blank month on a maximum holding are 12.5%, so the odds of three are 12.5% ^ 3 = 0.2%

How did you get 0.2% for the blank 3 month odds?

I can see that 0.2% is 12.5% cubed, but is it ok to multiply odds in this case?

Yes, cubing is the way to calculate the odds for three months from the odds for one - working out the odds of not winning anything is actually very straightforward, as the odds of winning a prize are 1 in 24,000, so the odds of a bond not winning in any given draw are 23,999/24,000.  Raising this to the relevant power gives the answer for multiple bonds and/or multiple months, so the odds of nothing in one draw from a maximum holding are (23999/24000)^50000 = 0.125, i.e. 12.5%, and for three months it's simply (23999/24000)^(50000*3) = 0.002, i.e. 0.2%.

SVts

I've just invested 25k but after reading this thread I am regretting it already. My first eligible draw is June so I'll wait until then and see what happens. Think I'd be better off accepting the guaranteed £75 from Chip each month.

basill

Brie said:

Stupid question being inserted here:  Do you have to check your account to see if you have won? 

OH & I have a tiddly £1k each and have done so since November.  I'd love to discover I'd won a fat prize.

There is an app, you can check for winnings without having to sign in each month.

eskbanker

SVts said:

I've just invested 25k but after reading this thread I am regretting it already. My first eligible draw is June so I'll wait until then and see what happens. Think I'd be better off accepting the guaranteed £75 from Chip each month.

When Chip are paying 3.71% on an easy access account then that's generally going to be a better bet than PBs with their notional rate (over the long term) of 3.3%, but realistically more like 2.6% on average, unless higher rate tax comes into play.  A thread for people who've been unlucky is fairly self-fulfilling and won't be representative of the general population, it's the same principle as basing decisions on TrustPilot reviews!

JohnWinder

eskbanker said:

JohnWinder said:

eskbanker said:

The odds of a blank month on a maximum holding are 12.5%, so the odds of three are 12.5% ^ 3 = 0.2%

How did you get 0.2% for the blank 3 month odds?

I can see that 0.2% is 12.5% cubed, but is it ok to multiply odds in this case?

Yes, cubing is the way to calculate the odds for three months from the odds for one - working out the odds of not winning anything is actually very straightforward, as the odds of winning a prize are 1 in 24,000, so the odds of a bond not winning in any given draw are 23,999/24,000.  Raising this to the relevant power gives the answer for multiple bonds and/or multiple months, so the odds of nothing in one draw from a maximum holding are (23999/24000)^50000 = 0.125, i.e. 12.5%, and for three months it's simply (23999/24000)^(50000*3) = 0.002, i.e. 0.2%.

Thanks. But I wonder if you’re confusing odds with probability.

Odds is the number of outcomes (a prize) compared with the number of non-outcomes (no prize). Probability is the number of outcomes compared to all outcomes, commonly ‘the chance something will happen’, eg 5 out of every ten (prob = 0.5) whereas the odds would be 1, ie an outcome for every non-outcome.

‘as the odds of winning a prize are 1 in 24,000, so the odds of a bond not winning in any given draw are 23,999/24,000. ’

I know that first figure comes from NSandI, but you’ve expressed, as odds, what is a probability, since two mutually exclusive probabilities must add to 1, which yours do. Two odds don’t have to add to 1, and rarely do.

‘odds … are calculated as the ratio of the number of events that produce that outcome to the number that do not.’ https://en.wikipedia.org/wiki/Odds

‘, probabilities can be numerically described by the number of desired outcomes, divided by the total number of all outcomes.’ https://en.wikipedia.org/wiki/Probability

Secondly, here’s a link advising that you can multiply probabilities of independent events to give you the chance of all outcomes being the same: 

‘you can calculate the total probability by multiplying the events’ separate probabilities by one another. This will give you the probability of multiple events occurring one after another.’ https://www.wikihow.com/Calculate-Probability

If you have a link you can share which shows we can multiply odds, and what the result means, please do. I can’t find one.