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I've been performing OOTW again and usually give some long winded and totally wrong spiel about the odds of getting all black and reds together being so short you are more likely to die on the spot or win the lottery or something along those lines. However I am interested in what the actual odds are of getting this right.
I've tried to do some maths myself but don't think I'm doing it right.

Does anyone here know the answer? Should be interesting.

Have words with Lawrence, apart from maknig superb R&S products he's a bit of a maths whizz.

Like Carol Vorderman but with less attractive legs... so they tell me...

Well, the chance of getting any one card right is 1 in 2. Two cards is 1 in 4, etc. I think that the overall odds are 1 in 281,474,976,710,656 for standard OOTW (much, much worse than winning the National Lottery jackpot). Different versions have even worse odds, for example, for Galaxy that figure must be multiplied by 4, because only two marker cards are used. If Lawrence comes along and says something different, trust him. I am not maths whiz!

The exact answer is more complicated than this, because in OOTW, it is theoretically possible for the spectator to put too many cards in one pile, which of course would render the desired outcome impossible.

My wife is always accusing me of being a smart A** and I'm thinking this is the perfect example as to why.

The odds of getting OOTW correct are fairly easy to calculate. 100% each and every time provided you perform it correctly because it is not left to chance.

yeah I know but I couldn't resist.

Mandrake wrote:Have words with Lawrence, apart from maknig superb R&S products he's a bit of a maths whizz.

Like Carol Vorderman but with less attractive legs... so they tell me...

Yes agree, Lawrence does make nice R@S products, as I've met him a couple of times. But maths whizz,? he's a accountant!!

Hello
chance of getting card 1 correct is 26/52 (1/2) however chance of getting the 2nd one right is now 25/51 (slightly off from 1/2)

So, chance of getting all 26 is

26*25*24*...*1
------------------
52*51*50*....*27

=

403,291,461,126,606,000,000,000,000
--------------------------------------------------
199,999,709,752,404,000,000,000,000,000,000,000,000,000


is odds of 495,918,532,948,104:1


But in reality, just say whatever number you feel like



Also, got the roofer in putting the top on my workshop this week so I'll have my roughing workshop up and running shortly.
Watch this space for deals, new products and custom creations!

Lawrence wrote:Hello
chance of getting card 1 correct is 26/52 (1/2) however chance of getting the 2nd one right is now 25/51 (slightly off from 1/2)

So, chance of getting all 26 is

26*25*24*...*1
------------------
52*51*50*....*27

=

403,291,461,126,606,000,000,000,000
--------------------------------------------------
199,999,709,752,404,000,000,000,000,000,000,000,000,000


is odds of 495,918,532,948,104:1


But in reality, just say whatever number you feel like



Also, got the roofer in putting the top on my workshop this week so I'll have my roughing workshop up and running shortly.
Watch this space for deals, new products and custom creations!

Nice odds..

Thanks guys, I use a mathematical/science theme to my tricks (as I work in a chemistry lab and most of my specs are undergrad students). I'll try and dazzle them with these crazy odds.

Part-Timer wrote:Well, the chance of getting any one card right is 1 in 2. Two cards is 1 in 4, etc. I think that the overall odds are 1 in 281,474,976,710,656 for standard OOTW (much, much worse than winning the National Lottery jackpot). Different versions have even worse odds, for example, for Galaxy that figure must be multiplied by 4, because only two marker cards are used. If Lawrence comes along and says something different, trust him. I am not maths whiz!

The exact answer is more complicated than this, because in OOTW, it is theoretically possible for the spectator to put too many cards in one pile, which of course would render the desired outcome impossible.

Yeah, the issue here is that you're dealing with a finite number of cards. The first card is 50/50, but then it gets super complicated because if, for example, the first card was red, then you're left with 26 black cards and 25 red cards, so the odds of getting the card right depends on whether it has been placed in the red pile of the black pile. That's before you even get to the complication of separating into two uneven piles.

Actually, that's the odds of drawing all reds or all blacks from the deck.
If you don't mind which one you're getting then you can cut those odds in half

Lawrence wrote:Hello
chance of getting card 1 correct is 26/52 (1/2) however chance of getting the 2nd one right is now 25/51 (slightly off from 1/2)

The problem I had (possibly self-created), was that what you are really trying to do is work out whether the spectator will get it right. For example, if he or she puts down three black cards (assume correctly), then the chances of the spectator guessing right is still approximately 50/50. The very next card has a slightly higher chance of being red than black, but actually what we are working out is, in effect, whether the spectator will jump the right way. Depending upon whether the spectator goes the "right" way or not, the odds of the guess being correct could be greater than 50% or less than that. That was giving me a headache, so I kept it simple.

One thing I did wonder about was whether you might have calculated the odds for separating the entire deck.In OOTW, the spectator only matches 48 cards (hence my comment that other OOTW effects might have different odds).

Part-Timer wrote:

Lawrence wrote:Hello
chance of getting card 1 correct is 26/52 (1/2) however chance of getting the 2nd one right is now 25/51 (slightly off from 1/2)

The problem I had (possibly self-created), was that what you are really trying to do is work out whether the spectator will get it right. For example, if he or she puts down three black cards (assume correctly), then the chances of the spectator guessing right is still approximately 50/50. The very next card has a slightly higher chance of being red than black, but actually what we are working out is, in effect, whether the spectator will jump the right way. Depending upon whether the spectator goes the "right" way or not, the odds of the guess being correct could be greater than 50% or less than that. That was giving me a headache, so I kept it simple.

I'll be honest... I have no idea what you just said!

Lawrence wrote:I'll be honest... I have no idea what you just said!

As we are trying to work out real world probabilities, that might mean I'm on the right track!

I've just tried to put it in simpler terms and failed, so let's call it a day!

Did you know:
You've got just as much chance of winning the lottery by playing the same numbers that won last week, or 1 2 3 4 5 6, as you do with whatever random 6 numbers you usually play with.
Yeah, thing is, 1 2 3 4 5 6 or last weeks numbers aren't going to come up are they?

Lawrence wrote: Did you know:
You've got just as much chance of winning the lottery by playing the same numbers that won last week, or 1 2 3 4 5 6, as you do with whatever random 6 numbers you usually play with.
Yeah, thing is, 1 2 3 4 5 6 or last weeks numbers aren't going to come up are they?

yeah but imagine the look on their faces when 1 2 3 4 5 6 does win, and then they realise that about 1000 other people are all sharing the top prize.

Back to OOTW.
Why use 52 cards? its gets soooo boring doing lots of dealing. though after half way you can tell them they can put several onto the same pile if they want.

I use a reduced set of Zenner cards with their red and black backs (e,g, beyond ESP)
They put the symbols (face up) into one of two piles and can mix up the symbols (i.e. tell them don't put all the same symbols into one pile, just whatever pile feels natural to you.)
magically separate and then turn the piles over to show red and black backs.

Unlike 'white star' or other variants they won't remember that a particular symbol (person/playing card) went into a certain pile when they examine everything afterwards.