Question about card shuffling.

[clarsct]

Not a magician, and not looking for 'secrets' as it were.

If I had a deck of 40 red cards and 20 black cards that you had never seen before, would it be possible for you to shuffle the deck in front of me so that the 20 black cards were in the bottom half of the deck?
(Without being caught.;) )
I'm just asking if there was a way to do this, if anyone knows a method by which it could be done.

[firecoins]

Not a magician, and not looking for 'secrets' as it were.

If I had a deck of 40 red cards and 20 black cards that you had never seen before, would it be possible for you to shuffle the deck in front of me so that the 20 black cards were in the bottom half of the deck?
(Without being caught.;) )
I'm just asking if there was a way to do this, if anyone knows a method by which it could be done.
yes its possible. yes I know a method. your not a magician so why would I share it?

[clarsct]

Wasn't asking you to share.;)

I was asking if there is a way to do so with a deck you've never seen before. I walk in with a deck, but you know the ratio of black/red.

I shuffle it, then you shuffle it, without obviously looking. Then I can pull the first thirty+ cards from the top and find all red cards.

I'm looking to see what is possible, what is doable by your average, trained human being.

Could you put three black cards in the top ten, then the rest on the bottom? Is there any limit to how you could stack the deck, without most people noticing?

[davefoc]

I believe what I will say below is within the spirit and intent of the rules against discussing how magic tricks are done. If it isn't then I apologize in advance.

I don't know how the trick is done, however, based on a reading of books on card tricks, I believe it is possible for some skilled individuals to shuffle a deck so as to produce a perfect interleave.

In thinking about the OP post question it seems like if one were able to shuffle so as to produce a perfect two to one interleave from a stack of forty cards and a stack of twenty cards and then one were able to produce a perfect interleave from two equal stacks one could, with a sufficient number of shuffles, arrive at the point that the all the cards of one color were together and stacked above the cards of the other color.

Personally, I wouldn't have guessed that it was even possible to shuffle with a perfect interleave when stacks of equal size are used, but it seems that it might be. Whether it is possible to do a perfect interleave with stacks of different sizes I don't know but if it is, very high card manipulation skills would seem to be required.

[clarsct]

Ah, but if I shuffle the deck first?

[jmontecillo01]

When I was young, I had a cousin who can produce a result of 4 aces taken from the top of the deck after he shuffled it. I can't remember of he allowed us to shuffle the cards first before giving the deck to him.

But we also always fall for one of the "magic tricks" of the older cousins who told us that if we look very closely, we would be able to see a coin pop out of the onion as they slice it.

[Dinsdale Piranha]

Wasn't asking you to share.;)

I was asking if there is a way to do so with a deck you've never seen before. I walk in with a deck, but you know the ratio of black/red.

I shuffle it, then you shuffle it, without obviously looking. Then I can pull the first thirty+ cards from the top and find all red cards.

I'm looking to see what is possible, what is doable by your average, trained human being.

Could you put three black cards in the top ten, then the rest on the bottom? Is there any limit to how you could stack the deck, without most people noticing?

It's possible but difficult. Learning to do these types of shuffles can take years of practice to perfect and look natural.

This would be more along the lines of gamblers moves, i.e. riffle stacking, etc.

There are books and videos available to learn these moves. Basic card handling technique is a prerequisite of learning advanced methods.

[Cain]

The OPer's scenarios are inconsistent. Why are you positing 40 cards -- 20 red, 20 black -- and then talk about the first thirty cards being red. Why not just assume a regular deck of 52 throughout?

Dave-
I don't think I'm giving anything away you don't already know, but it is absolutely possible to perfectly interleave the cards. It's a well-known shuffle and many skilled card magicians can do it nearly 100% of the time. Indeed, Darwin Ortiz can do it with one hand. And of course, as you'll learn in a lot of self-working, math-based books, eight such shuffles returns the deck to its original order.

Stacking a randomly mixed deck is not easy. Lennart Green has some interesting ideas on the appearance of chaos. He allows a spectator to very fairly shuffle a pack that he's already been mixing. Then spectators name out any card and he produces it in short order (without looking through the cards, of course).

[T'ai Chi]

When I was young, I had a cousin who can produce a result of 4 aces taken from the top of the deck after he shuffled it. I can't remember of he allowed us to shuffle the cards first before giving the deck to him.


Was it a stripper deck or a regular one?

[firecoins]

Dave-
I don't think I'm giving anything away you don't already know, but it is absolutely possible to perfectly interleave the cards. It's a well-known shuffle and many skilled card magicians can do it nearly 100% of the time. Indeed, Darwin Ortiz can do it with one hand. And of course, as you'll learn in a lot of self-working, math-based books, eight such shuffles returns the deck to its original order.
Your not giving anything away by revealing the faro.

Riffle stacking can be used to get control of the deck.

[T'ai Chi]

Has anyone actually seen a video of a perfect interleave?

[firecoins]

Has anyone actually seen a video of a perfect interleave?
yes and I can do one. The hard part is getting an exact cut. I cut 25 or 27 quite often.

[Bob Klase]

Has anyone actually seen a video of a perfect interleave?

Haven't seen a video, but I've seen it in person on a few (hundred) occasions. That's not counting the times I do it myself.

[Cain]

Just go to Youtube and punch in "perfect faro"; I'm sure you'd get some hits.

Your not giving anything away by revealing the faro.

Well, it does sort of give something away. When a magician walks up and spreads the cards to show they're random and then gives them a couple of genuine (perfect shuffles) to restore a mem stack. This is what Michael Close does. He claims its better than doing false shuffles. Same goes for Darwin Ortiz.

Lennart Green, as I mentioned before, has some interesting ideas on the appearance of chaos. He says the layperson cacluates as follows: 3 faros = 2 riffle shuffles = 1 Rosetta Shuffle. This in spite of the fact that one faro (doesn't have to be perfect) shuffles the cards more than either of the other two. It's just a bit too neat.

[NeilC]

Re: the OP - if you shuffled a normal deck and mixed it up properly then it would be very hard indeed, if not impossible, for someone to then shuffle it and sort out the black/red order without obviously looking at it.

But if you used the magician's pack it would be simple. Also, if you used your own pack but allowed the magician to shuffle it first and then you shuffled it, depending how you shuffled it, then it would be possible. In fact I do a trick which uses this last possibility, but in the UK we tend to do overhand shuffles and not riffles, which alters things.

[firecoins]

edited

[RSLancastr]

The OPer's scenarios are inconsistent. Why are you positing 40 cards -- 20 red, 20 black -- and then talk about the first thirty cards being red. Why not just assume a regular deck of 52 throughout?Re-read the OP. It says 40 red cards and 20 black cards.

I have no idea why a 60-card deck is being used, but that's what it says.

[Dinsdale Piranha]

Re-read the OP. It says 40 red cards and 20 black cards.

I have no idea why a 60-card deck is being used, but that's what it says.

The 60 card deck is the standard on Planet X.

[firecoins]

Re-read the OP. It says 40 red cards and 20 black cards.

I have no idea why a 60-card deck is being used, but that's what it says.
while were on it, if I hand you a deck and tell you to false suffle it, it is that much more difficult to do it undetected, Of course gamblers wouldn't have a problem either way.

[deBergerac]

Lennart Green, as I mentioned before, has some interesting ideas on the appearance of chaos. He says the layperson cacluates as follows: 3 faros = 2 riffle shuffles = 1 Rosetta Shuffle. This in spite of the fact that one faro (doesn't have to be perfect) shuffles the cards more than either of the other two. It's just a bit too neat.

I think that he might be right. When you see him perform the cards are flying everywhere and it is very difficult for people to realise that he knows what he is doing. And a Rosetta shuffle looks a lot more random than a riffle shuffle or a farao shuffle for the untrained eye.

It is of course possible to force conditions on a magician that will make it impossible for him to stack the deck to have 30 red cards on the top. But you would have to know a bit about cardwork to know how to set up the "experiment". Just handing him a shuffled deck of cards is not enough to make it impossible.

[clarsct]

*chuckle*

Yes, a sixty card deck. Magic:The Gathering plays with a sixty card deck, with approximately 20 of it being land.

I play in tournaments in my area. You are allowed to shuffle your opponents deck. Recognizing a land card at a quick glance would be about as difficult as picking a black card out of a deck of red cards, thus the example I used. (If you were peeking! Which, of course, you would have to.)

A person who plays the same circuit as I do wins. Every time. Every time, the person who loses does not get enough land to run the deck(this goes into rules that are relatively unimportant to the scenario). His opponents stop at three land. Consistently. TOO consistently, say about 9 times out of ten or higher. I am suspecting foul play, and so are quite a few others.

I am asking for informational purposes. Is it possible to stack the deck this way? I do not wish to do so, I am interested in deckbuilding as a skill and the competitiveness of the game. But I am also not happy about someone playing shenanigans when there is a prize on the line.

If this is possible, then I must move on with looking at how to spot card tricks so I can call him on it. This research I will do elsewhere, as not to break the rules on revealing of secrets. But I need a solid start point to move from.

Sorry I asked in a roundabout way, but all I have at the moment is suspicions. I was hoping a more abstract example might be useful to the discussion.

The decks are generally sleeved, if that makes a difference. (I wouldn't think so, but then again every card trick I have ever attempted, I've screwed up!!)

[Cain]

OK, I am familiar with Magic: The Gathering (I played about 10 years ago). Anybody want my four Force of Wills?

So, sixty cards, eh? Well, the deck is already shuffled, so it would be pretty difficult to landhose someone. Also, sleeves make it much more difficult to handle cards adeptly, and I'm assuming they don't allow for easy faros (because that would split the sleeves). Can you confirm he does not faro (weave) shuffle?

An image of how this is basically done can be found here: http://www.21ace.com/images/faro-card-shuffle-3.jpg

He's also not allowed to look through the cards, right? And the sleeves have a black back (not that it would matter if the cards are marked because he's using someone else's deck). It just sounds like a coincidence to me. Separations are usually done by looking through the cards faceup.

Now of course there are overhand culling techniques. Jimmy Molinari is supposed to be one of the best: http://www.jimmycards.com/

Click on movies and watch his overhand cull. Now with this queens are 1 to 13, whereas land, as you said, is 1/3.

[firecoins]

http://www.dennymagic.com/cgi-bin/hazel.cgi?client=76865243&action=detail&item=007478

learn the basics of sleight of hand

[Dinsdale Piranha]

http://www.dennymagic.com/cgi-bin/hazel.cgi?client=76865243&action=detail&item=007478

learn the basics of sleight of hand

The paperback edition of the book can be purchased in most bookstores for $15 or less. Required reading for sleight of hand with cards.

[Squishua]

Not a magician, and not looking for 'secrets' as it were.

If I had a deck of 40 red cards and 20 black cards that you had never seen before, would it be possible for you to shuffle the deck in front of me so that the 20 black cards were in the bottom half of the deck?
(Without being caught.;) )
I'm just asking if there was a way to do this, if anyone knows a method by which it could be done.
Almost certainly - as long as I know ahead of time that you are going to ask me to do it. ;)

(and I'm not even a magician, and my sleight of hand skills are rudimentary)

-Squish

[Unalienable]

It's almost impossible to achieve the effect you want to achieve (i.e. getting your opponent "land screwed" in a tournament game) without looking at the cards. Not impossible, but almost impossible. There are ways to riffle shuffle a deck so that it's possible to peek under the cards as they fall down, but even then it would take many riffle shuffles--you couldn't just do it with one shuffle.

I've considered ways that sleight of hand could be used to cheat in Magic the Gathering. One possibility is that all of your land cards are marked on the back, and you work on a hot "second deal" so that if you want a land, and it's not on top, you do a second deal to yourself to help enhance the odds. Or if you have plenty of land and you see a land coming up, you second deal. The problem is that the nature of the game doesn't require you to pick the deck off the table and "deal" to yourself like it was a game of Blackjack or Poker, you are only taking one card at a time, that's not so easy. Probably the best cheat would be some method for holdouts, essentially you have extra cards on your person that you could swap in/out for cards in your hand.

[clarsct]

Happy Birthday!

I was more concerned with peeking while doing a regular shuffle(folding the cards into each other? You hold the deck in one hand and shuffle with another, I dunno the technical term) If you hold the cards right, you can see what's there.

[Bob Klase]

I was more concerned with peeking while doing a regular shuffle(folding the cards into each other? You hold the deck in one hand and shuffle with another, I dunno the technical term)

Sounds like you mean "overhand shuffle".