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Michael Daniels Inner circle Isle of Man 1609 Posts |
A different but related fact is that it has been shown mathematically that it takes six or seven successive ordinary (not perfect) riffle shuffles to truly randomise a deck.
Wikipedia has some useful information on shuffling http://en.wikipedia.org/wiki/Shuffling Mike |
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mastermindreader 1949 - 2017 Seattle, WA 12586 Posts |
Mike is right. Charles Jordan (and countless others) created scores of effects based on the cyclic nature of the riffle shuffle. (A few overhand shuffles following the riffle shuffles, though, speeds up the randomization.)
Best- Bob |
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psychicturtle Special user UK 821 Posts |
Yeah, you're all forgetting that Looch just cuts the pack over and over thinking he's 'shuffling' it. Bless him.
;D |
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nlokers Regular user Grand Rapids, MI 142 Posts |
It seems to me that the possibility of "randomizing" a fully mixed deck and having it go back into new deck order would be 52 factorial. But the act of randomizing would mean that each card has an equal chance of winding up anywhere else in the deck, where as with riffle shuffling that is not the case.
For example, if you cut the deck and the top card of the left hand packet is AS,and the top 2 cards of the right hand packet is 3S then 2S, there is no way that you are going to be able to riffle shuffle them so that they end up in A,2,3 order. I know this isn't an answer, but I felt like saying it. |
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Daegs Inner circle USA 4291 Posts |
It would take, on average, half of the time listed in the following link:
http://www.schuhmacher.at/weblog/52cards.html |
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DekEl Inner circle Creates MindTricks. Has exactly: 1172 Posts |
I remember reading somewhere that eight perfect Faroe will do it for you. Which means for me that it's impossible.
You can purchase my works at: http://www.GetMindTricks.com
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Looch Inner circle Off by 3362 Posts |
Quote:
On 2011-01-04 17:30, psychicturtle wrote: Does cuts not count? lol
Mentalism Products: https://www.readmymind.co.uk/ Learn Mentalism with the Pro's: https://www.mymind.rocks
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Paul.W Veteran user 338 Posts |
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Stefmagic Special user 529 Posts |
Quote: Michael Close is the master of perfect faro shuffle and on his new DVD Devious, there is a couple of mindboggling impossible routine using faro shuffle!
On 2011-01-04 14:57, Garrette wrote: |
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Garrette Special user 926 Posts |
Quote: His starting point in the video was a deck in new-deck order. My amateur research indicates I was correct; 8 perfect shuffles returns the deck to the order it was in when you started; it does not return it to new-deck order.
On 2011-01-05 05:32, Paul.W wrote: You can simulate this by creating your own smaller deck and simply manually interweave them 8 times or 16 times or whatever you like. I did it with 8 cards. |
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Dick Christian Inner circle Northern Virginia (Metro DC) 2619 Posts |
Quote:
On 2011-01-05 07:06, Garrette wrote: I don't understand the above assertion. If you start with the deck in new deck order and, after a number of perfect shuffles (forget for a moment the number of shuffles required) it is back in the order it was when you started (i.e., new deck order) how can it NOT have been returned to new deck order. For what it's worth, I have never been able to master the faro shuffle. When I did my experiment years ago I started with a deck in new deck order and simulated a perfect riffle shuffle by cutting the deck exactly in half and then repeatedly interweaving the two halves and counting how many times I had to do that in order to return the deck to the starting condition (i.e., new deck order). As Tony has indicated whether 8 or 16 such shuffles are required may well depend on whether the interweaving replicates an in faro or an out faro. In any event, I defer to those who are far better card experts than I.
Dick Christian
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Garrette Special user 926 Posts |
Quote: Earlier I said that I assumed that the series of perfect shuffles would return a deck to its new deck order only if new deck order was the starting point. Someone replied that the deck need not start that way to end up that way. I accepted that assertion provisional upon my checking it. After checking, I found out what I had originally suspected: perfect shuffles will only return a deck to the order in which it started, not to the new deck order (unless that's how it started).
On 2011-01-05 07:22, Dick Christian wrote: Of course, it's possible that I misunderstood what the previous poster said and have been checking something that was never asserted. Does that clear it up or muddy it? Edit to add: In other words, the 8 perfect shuffles (or 16) will return the deck to new deck order if and only if it was in new deck order when you started the shuffling. Otherwise it will return it to whatever order the deck was in when you started, for instance a stack. |
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The Paranormalist Special user United Kingdom 702 Posts |
Hi Looch
I don't know if you got the answer to your question but here are some facts tht might be of interest: • An ordinary pack of playing cards can be arranged: 80, 660, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000 different ways. • In the card game of bridge there are a possible 635,013,559,600 different thirteen-card hands. • The odds against all four contact bridge players being dealt a complete suit each are: 2,235,197,406,895,366,368,301,599,999 to 1. • There are 120 ways to lay down 5 cards. Franklin |
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psychicturtle Special user UK 821 Posts |
Quote:
On 2011-01-05 05:12, looch wrote: I'm sorry Looch, but I just couldn't resist! |
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TomasB Inner circle Sweden 1144 Posts |
In case it has not been clearly written yet: 8 outfaros gets you back to the starting position in a 52 card deck. 26 infaros reverses the order so, of course, 52 infaros gets you back to the starting position.
/Tomas |
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landmark Inner circle within a triangle 5194 Posts |
I always slip up on that 51st faro.
Click here to get Gerald Deutsch's Perverse Magic: The First Sixteen Years
All proceeds to Open Heart Magic charity. |
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