Talk:Shuffling

message: Do not delete this page because someone will say "This isn't an encyclopedia article", as it is useful. -- 67.20.29.3 22:03, 2 Apr 2004 (UTC)
replies: text:  "Also I'm told : Donald E Knuth, The Art of Computer Programming (Chapter 3.4.2), and he also gives the original publishers of this algorithm: L.E.Moses and R.V.Oakford (1963) and R Durstenfeld (1964)" - 82.163.24.100 21:34, 9 July 2007 (UTC)
thread_title:  Opening comment 

message: The Riffle shuffle and Faro shuffle are the same thing.  They both interleave the cards one-by-one from alternating sides, and can be done either as an in shuffle or out shuffle.  They may differ by the actual way the hands are held to accomplish the shuffle, but the result is the same.  The two sections should be merged.  At the very least, the text needs to SAY that they are the same and there should be a link to the Faro Shuffle page from within the Riffle shuffle section.  If the two sections are not merged, then at least the Faro Shuffle section should immediately follow the Riffle shuffle section.  — Preceding unsigned comment added by Tedtoal (talk • contribs) 22:27, 5 April 2020 (UTC)
replies: text: Agreed.  I had previously believed that the Overhand was called Faro.  I specifically came to the Talk half of this page because here the Faro and Riffle are the same thing, and it confused me. Lepome (talk) 17:27, 23 March 2023 (UTC)
thread_title:  Riffle and Faro are really the same 

message: The "Knuth shuffle" is something I've previously encountered as the Fisher-Yates shuffle, e.g. see , , . The first of those links cites "R. A. Fisher and F. Yates, Example 12, Statistical Tables, London, 1938.", which obviously predates any algorithms invented by Knuth. I've added a mention of the name Fisher-Yates shuffle. Graue 01:02, 29 May 2005 (UTC)
thread_title:  Fisher and Yates 

message: "concluding that it did not start to become random until five good riffle shuffles, and was truly random after seven. (You would need more shuffles if your shuffling technique is poor, of course.)"
In particular, I'd like to refer to the quoted sentence in brackets. It's quite untrue. In fact, the number seven in shuffling refers more to "perfect shuffles" than anything else. Imperfect shuffling, that is, when cards from each shuffling pile do not perfectly intertwine, produce more random results, if anything. While perfect, or close to perfect, shuffling produces predictable results, imperfect shuffing does not. So I think the bracket should be simply deleted from the article, since it's mathematically incorrect.
-- anonymous
I think it is true. Let's myopically focus on the card at the very top of the deck (say it's the ace of hearts). If the deck is "truly random", then there should be an equal probability that the AoH is in any location, right?
Let's say I always grab the top of the deck with my left hand, and then grab the bottom of the deck with my right hand.
Say I always flip through the half-deck in my right hand faster than the half-deck in my left hand (poor riffle shuffling technique).
Then once I've used up all the cards in my right hand, all the remaining cards in my left hand get thrown on top of the stack.
No matter how many times I riffle shuffle, that ace of hearts is thrown to the top of the stack. Not very random.
Say I *try* to make it more random by occasionally grabbing the top of the deck with my other hand.
After 5 shuffles, the AoH is still likely to be somewhere in the top half of the deck.
Better, but still not truly random.
But after a few more riffle shuffles (occasionally switching which hand grabs the top of the deck), it gets closer to truly random.
On the other hand, I agree that "perfect" riffle shuffling isn't exactly random either.
--DavidCary 23:34, 11 January 2006 (UTC)
thread_title:  imperfect shuffling 

message: I disagree that the bridge "technique" after a riffle shuffle is just for showing off. On softer paper playing cards, the cards bend easily from a riffle shuffle, and the bridge bends them back, keeping them straight. 70.111.224.85 19:05, 11 January 2006 (UTC)
thread_title:  Riffle and Bridge 

message: The pile shuffle section contains the statement: "This is the only method of human shuffling approved in bridge when four piles are used (each pile is then assigned to the four players in this game)".  This can't possibly be correct; as is correctly pointed out above, the pile "shuffle" is hopelessly non-random and wholly inadequate. Please provide a reference or remove.  --LDC 14:38, 1 June 2006 (UTC)
replies: text: Is it just me, or is the pile shuffle as described for use in bridge ("each pile is then assigned to the four players in this game") just a description of dealing the cards? --VinceBowdren 18:35, 21 November 2006 (UTC)
thread_title:  Pile shuffle 

message: Someone changed my "five seconds" claim for the speed of a good casino shuffle to fifteen; I can't imagine any experienced poker dealer that slow being able to keep a job for long. --LDC 22:19, 3 June 2006 (UTC)
thread_title:  Speed 

message: Per Wikipedia:Naming conventions, shouldn't this article be at Shuffling? If there are no objections filed within a week or so, I'll move it there. howcheng  {chat} 23:19, 2 October 2006 (UTC)
thread_title:  Proposed move 

message: I removed  this sentence from the "False shuffles" section because it seemed meaningless:
: It is most commonly to "stack the deck" (place cards into a desirable order) by means of one or more riffle shuffles; this is called "riffle stacking".
If I'm wrong, feel free to put it back.  (But maybe explain it better: I don't know of a way to put a deck in order using anything that looks like a riffle shuffle, though I do know of ways of performing false riffle shuffles which don't disturb decks stacked previously by some other technique.  And at any rate, whatever this "riffle stacking" thing is, it certainly isn't "most common"!) —Steve Summit (talk) 03:56, 11 November 2007 (UTC)
replies: text: Aha.  The sentence made more sense before this edit a year ago.  Restoring. —Steve Summit (talk) 04:09, 11 November 2007 (UTC)
thread_title:  "riffle stacking"? 

message: I propose that Overhand shuffle be merged into shuffling as it contains no information that this one doesn't have, nor does it even define what an overhand shuffle is. further, I doubt wetter there is enough relevant information that could be added to overhand shuffle that would justify it's existence as a seperate article.131.155.215.91 (talk) 14:35, 1 December 2011 (UTC)
replies: text: Or simply remove the Overhand shuffle article as it isn't really shuffling, but what people do that can't shuffle or magicians do to false shuffle.Objective3000 (talk) 15:11, 1 December 2011 (UTC)
thread_title:  Merger proposal 

message: Surely the overhand shuffle is not correctly described. As it stands at the moment the description is of the repetition of a simple cut. If we take the order of cards as a circular sequence that can start at any point then the sequence is not changed at all by repeated cuts - only the starting point of the sequence changes. If anyone agrees I will write description of a proper overhand shuffle. Mike Spathaky (talk) 11:44, 30 November 2014 (UTC)
replies: text: No, this is not simply repeated cuts as the grabs are smaller than half the deck. And, they are not equal in size. What is described is a tops only strip. It is a not uncommon part of a shuffle in casinos. Of course, it is only one step as it doesn't shuffle nearly well enough. O3000 (talk) 18:21, 12 October 2017 (UTC)
replies: text: Well the article as you have reverted it says it's repeated cuts ("essentially a series of cuts") and what it describes is repeated cuts. A cut doesn't have to be exactly (or even nearly) into halves. I stand by what I have said, that a cut does not shuffle the pack at all, and so multiple cuts don't either. I would like others' opinions on this before I restore my edit. Mike Spathaky (talk) 21:30, 13 October 2017 (UTC)
replies: text: Of course it shuffles it if the cuts are of different sizes. Just not very well. (And one of the reasons home Poker games are easy to beat. Home players don't shuffle well.) Which is why a casino also riffles (among other steps). Try it. O3000 (talk) 21:40, 13 October 2017 (UTC)
replies: text: "Of course" doesn't affect the logic of my explanation above ("Surely..."). Perhaps I am misunderstanding the description in the article, but as it stands it is a description of a series of cuts -- it says as much. A cut does not move a single card from its neighbours apart from the the top and bottom cards which come together and the two cards either side of the cut point which become the new top and bottom. At the next cut the latter two come back together. This is true wherever in the pack the cut point lies. Try it with a new pack (orderd by suits and numbers). Mike Spathaky (talk) 07:51, 14 October 2017 (UTC)
replies: text: Unless you keep cutting in exactly the same spot, what you are saying is not true. Try it with a deck of cards. O3000 (talk) 12:12, 14 October 2017 (UTC)

text: You aren’t following the instructions. You must make numerous grabs of different sizes. If you wish to replace with what you just proposed, go ahead as it says the same thing. O3000 (talk) 13:48, 14 October 2017 (UTC)
replies: text: Thank you, O3000. I have now made the instruction clearer, based on those in the Jonasson reference, with a little amplification. As for not following the instructions, I see no mention of "numerous grabs" in the original article. What was lacking was the mention of the release of the cards in a number of small packets. You yourself said (1 Dec 2011) that an overhand shuffle "isn't really shuffling" and that was true with the description given. But overhand shuffling is used the world over, is a valid way of shuffling and now we have have an accurate description of it. Best Wishes O3000, Mike Spathaky (talk) 19:50, 14 October 2017 (UTC)
replies: text: Yep, it’s used the world over and is a valid method of shuffling by definition. Which is why good card players can easily beat home games, particularly in Poker games where the cards are often set, like Draw Poker. It simply doesn’t shuffle adequately. More popular is just repeatedly jamming the cards together, which is actually better than overhand shuffling. O3000 (talk) 20:08, 14 October 2017 (UTC)
thread_title:  Overhand Shuffle

message: I added back a section yesterday that had been deleted with no reason given back in 2009, and now user:Objective3000 has reverted my edit just because it contained a link to a YouTube that is apparently an ad! Why could he not simply remove the link, if it's such a bad thing?? But there are probably people who would like to see the video.
:Wikipedia is an encyclopedia, not an advertising medium. If you can find a reliable source, you are welcome to add it. Objective3000 (talk) 01:09, 28 December 2014 (UTC)
thread_title: False shuffle