The Magic Café
Username:
Password:
[ Lost Password ]
  [ Forgot Username ]
The Magic Cafe Forum Index » » All in the cards » » Karl Fulves Effects (8 Likes) Printer Friendly Version

 Go to page [Previous]  1~2~3~4
casinoboss
View Profile
New user
76 Posts

Profile of casinoboss
For Psi-X, having the spectators cut each packet in addition to the shuffling should help quite a bit, right?
John7
View Profile
Regular user
130 Posts

Profile of John7
Well I just tried it twice. Once as written (to give it another chance) and then second - with a cut of each packet. The first attempt failed again - I got 4 cards that matched. One before the selection, the selection itself and then another two much further down the deck after the selection. The second attempt. with the cuts, actually worked. Only one card showed up in the right position - the selection. However there were a couple of other cards that were close - right next to their position. So it could have easily gone wrong. Maybe instead of a shuffle, you should do a cut and a wash shuffle or all three - a cut, a shuffle and then a wash shuffle. But that might start looking suspicious itself - too much emphasis on the shuffles.
casinoboss
View Profile
New user
76 Posts

Profile of casinoboss
Doing a small packet cut (eg 1/3 of the deck) followed by a riffle shuffle or just a series of packet cuts might yield the best results.
John7
View Profile
Regular user
130 Posts

Profile of John7
I just tried it once more. Gave the first packet a cut, overhand shuffle, 3 or 4 riffle shuffles and then another overhand shuffle. Gave the second packet the same treatment and I still got two cards in their right positions (the selection and another one). Fulves says that in this situation you need to employ fishing tactics to narrow the choices down ("Was your card a red card?"). He says this will happen rarely but I think it will happen most of the time.
casinoboss
View Profile
New user
76 Posts

Profile of casinoboss
I think you're OVER shuffling. A series of shallow packet cuts should appropriately displace the order 100%, right?
John7
View Profile
Regular user
130 Posts

Profile of John7
Sadly not - I got 8 matches. I think it's just a case of getting very lucky or fishing. Shame because the fishing kinda detracts from what the whole strong point of the trick would be if it worked as described - they shuffle both halves and then you look through the deck and immediately lay one card down.
Claudio
View Profile
Inner circle
Europe
1672 Posts

Profile of Claudio
Quote:
On Sep 29, 2021, John7 wrote:
Sadly not - I got 8 matches. I think it's just a case of getting very lucky or fishing. Shame because the fishing kinda detracts from what the whole strong point of the trick would be if it worked as described - they shuffle both halves and then you look through the deck and immediately lay one card down.


Suppose we shuffle a deck of cards; what is the probability that no card is in its original location? More generally, how many permutations of [n] = {1, 2, 3, . . . , n} have none of the integers in their “correct” locations? That is, 1 is not first, 2 is not second, and so on. That type of permutation is known as derangement of [n].

The probability of getting at least one match (unwanted in our case) is slightly superior to 60%, therefore more often than not you’ll have to fish.

Here’s an example with 4 cards labelled A,B,C,D.

The Original order is ABCD, after shuffling the cards, here are all possible outcomes (the ones highlighted are the ones with a match or more) (24, ie 4x3x2) of which only 9 have no match and the other 15 have at least one matching card -> 15/24 = 62%. This percentage (about 63%) is constant when n > 6.

ABCD
ABDC
ACBD
ACDB
ADBC
ADCB
BACD
BADC
BCAD
BCDA
BDAC
BDCA
CABD
CADB
CBAD
CBDA
CDAB
CDBA
DABC
DACB
DBAC
DBCA
DCAB
DCBA

If you want to know more about this, here’s a Wikipedia Link
The Magic Cafe Forum Index » » All in the cards » » Karl Fulves Effects (8 Likes)
 Go to page [Previous]  1~2~3~4
[ Top of Page ]
All content & postings Copyright © 2001-2021 Steve Brooks. All Rights Reserved.
This page was created in 0.19 seconds requiring 5 database queries.
The views and comments expressed on The Magic Café
are not necessarily those of The Magic Café, Steve Brooks, or Steve Brooks Magic.
> Privacy Statement <

ROTFL Billions and billions served! ROTFL