I wonder if there is a general accepted order of least suspicious grouping of the deck in two groups allowing quick inspection by spectators at some point.

The easiest is a red-black separation but which is obvious to spot, be it when two packets are presented or the groups interleaved and form an alternate sequence, so it is interesting if the cards are never seen by spectators or if the effects relies on a final reveal of red-black patterns.

Another way to group is spades with hearts and clubs with diamonds. Still easy to spot when two packets are shown but probably less obvious when interleaved.

even - odd is another easy candidate (with special treatments of kings)

Claussification based on number of letters in spelling yet another one and virtually undetectable (but a little bit more time consuming when needing to find an intruder in a group)

Finally index below or above 26 in a memorized stack yet another undetecable one with also a little work to find the intruder.

My examples are already somewhat classified but I wonder which of the classifications even-odd or Heart-Spades/Club Diamonds is best used when cards can be seen by spectators
a) in the original groups
b) in alternating order

Is there a generally accepted strategy ?

Thanks

For some years I used odds and evens. Then one spectator noticed it. My work around was to still use odds and evens, but with the clubs reversed. Like, club odd cards would go with the other even cards, and clubs even cards would go with odd cards. Kings had their own treatment (black with odds and red with evens).

I don't really do that anymore. Try it out, maybe it suits your presentation format.

One other idea would be to separate the cards in 4 groups. Like, red and black, and then odds and evens. Then you follow to combine those groups, like odd-blacks with even-reds, and even-blacks with odd-reds. With practice it should not be that time consuming to spot and intruder. You just have to develop and rigorously follow a pattern to find it. Like, first group, look first the blacks and see if there is an intruder, then look only the reds. Then go on to the second group. You would have to do it four times in some cases, but it shouldn't take you too long to get used to it.

One third, and difficult idea, which would be virtually undetectable by any spectator, is to be familiar enough with a memorized deck, like Mnemonica, Aronson or any other. Then separate the first 26 cards from the last 26. It's harder for the magician, but certainly impossible to spot by any spectator.

Points and Rounds.

Thanks for the feedback. In the meanwhile I found also:
http://www.themagiccafe.com/forums/viewt......&forum=2

and realize nobody seems to use the separation symmetric/ non symmetric cards (with Jacks grouped into the non-symmetric ones if a 26/26 separation is needed).

Many Bicycle decks are cut off center and effectively provide one-way backs because one end has wider margins than the other.

This one-way property is less obvious from the face side, but can be discerned if one is on the lookout for it.

See also Kabbalah's answer.

Red shadow cards and black shadow cards if 26/26 is needed.
Shadow suits if 4 x 13 is needed.
Shadow suits combined with closed/open if 8 x 6/7 is needed. ...
Shadow pairs of 26 x 2 if needed.

To those wondering what said 'shadow suits' are supposed to be: they're a fascinating discovery in card properties, recently made publicly available in this (German only) publication.

Basically it's way to discern each and every card's 'proprietary shadow identity' and use it to e.g. sort a deck by color without any evidence to the onlookers, enabling you - to further stretch given example - to perform Giobbi's TNT with the deck openly spread out at the beginning and the end!
Figure this!

But that's only the tip of the iceberg, of course; many more approaches are being discussed in the booklet and even more are yet to be disclosed.

Once you know what to look for you can't help to see every card in two different ways: for one, its regular color, suit and value - but then again also its secret shadow! 

Let's hope the book will soon find its way to the translators so it will become widely available for the sake of digging deeper into this new ground!

Do you have an appreciation how "difficult" it is to spot intruders in the shadow world compared
-to a memorized deck and the first 26 and last 26 cards ?
-to a normal even odd separation ?

IMHO something between this two options. Close to even/odd.

5-7 years ago, when Bicycle changed their box design from Rider to Standard, they also changed the size of the pips (and court card portraits) on the cards. The difference is very subtle, but very easy to spot if you're looking for it.

You could use any 26 cards from a small-pipped deck, and pull the other 26 from a current deck.

The smaller-pipped cards weren't produced for very long before they reverted to the usual art.

You can also just use Phoenix decks and divide them any way you want, as Phoenix decks have one-way faces and backs.

Many good suggestions here. I have used several of the suggestions. I would also add (unless they are above and I have missed them) ROBE/BORE (red odds and black evens in one half, black odds and red evens in the other), and sorting according to morphology of index, i.e., numbers with points or straight lines on the top of the number (A, 3, 4, 5, 7, J, K in standard Bicycle font) in one half, curves (2, 6, 8, 9, 10, Q) in the other. (Of course in this latter arrangement 10 can be in either group, and one might even split them to keep 26 cards in each half.) I also agree with the making the most of one-way design, but my misgivings about one-way work is that someone will change orientation of card or cards without me catching it.

But this all said, once I finally knew I had Mnemonica memorized cold, the only choice for me now is something based on the stack number associated with each card--usually 1-26 vs 27-52, very occasionally odd-even. This is my choice for Neither Blind nor Stupid, Paul Wilson's Absolute Zero, and of course the plethora of Aronson location effects that depend on what he calls retained relative groupings (RRGs), particularly High Class Location and S-D Plus. And of course there is the grand-daddy of divided deck effects, Histed Heisted, where cards are identified by considering them in a kind of grid and ruling them in or out accordingly. It took some time, but now I can think of any card and instantaneously remember not only the stack number, but what half of whatever division it is in. This simply came from working with the stack for hours at a time, manually stacking shuffled decks into Mnemonica any time I got my hands on cards, drilling the stack in my head during quiet moments, etc. Barring dementia or a major stroke, I am taking this to the grave

Les

I thought about using the fact that in a standard bicycle deck 22 are naturally one-way. If I assign four arbitrary other cards (for example jacks) to this group, the spectator can change orientation as he wants, it is the fact that a card is one way which defines his group, not the actual orientation. What is nice about it is that it is also a mix of suits and values without clear pattern (other than one-way...)

I developed an odd-even separation that is easy and invisible. Using the standard "SHoCkeD" numbering system for the suit, just add the face and suit values of the card. As a shortcut, you can just look at the parity of the face and suit values. If they are different (one even and one odd), the card is odd; otherwise it is even. I would be surprised if this has not appeared in print somewhere.

David M.

Ekgdoc wrote:
Note that this is identical to the ROBE/BORE division mentioned previously.

This is the method I've long used, and while it might take some practice, it's not too difficult. Before using a memorized stack, I spent a few years working with memorized separation. Group "1" uses cards that spell with 12 or 13 letters while group "2" is any other number. This means the spades and hearts perfectly overlap (3, 4, 5, 7, 8, 9, J, Q, K); you'll notice they come in consecutive groups of three. With clubs you can just brute force remember the one's that go in: (3, 7, 8, Q), all values that spell with five letters. In my head these cards often stick out: 3, 7, and 8 are regarded as "lucky" numbers, and the queen is the least like the other court cards.

Dividing a deck in this way means that you can perform Bannon's "Dead Reckoning," which was always my original intention. As it turns out, I've found it more useful to have an off-balanced separation (23-29 split, keeping only the 6D in group 1). The trick I by far use it for most often is an impromptu handling of Aronson's "Prediction Shufflebored" (using the six of diamonds as the magician-in-trouble kicker).

I've never had anyone notice the lack of diamonds in one half, or their relative commonneess in the other.

DDyment wrote:


Without a deck in hand, this was not so easy for me to see. So that I might contribute something here, I would note that one can use the ROBE/BORE division to aid clocking the deck. (I know that Doug Dyment has more than a passing interest in deck clocking since he wrote about it in one of his excellent booklets.)

David M.

I know the "spell count" of all the cards according the Flash Speller method Simon Aronson offers in Try the Impossible. It is helpful enough when I am dividing up the cards to stack the deck on my own time for full-stack tricks like his Trained Deck from SS and Worker Bees from TTI. But I just don't know the counts intuitively enough yet to find the odd one out quickly in a divided deck. This should work beautifully, as there are 26 12- and 13-spellers all together and 26 10-, 11-, 14-, and 15-spellers all together, so it is a perfect split. And I do agree that the dearth of diamonds in the 12/13 half (there are only the four, A-2-6-10) is no more noticeable than the asymmetric distribution of the clubs. I would think that someone who doesn't want to do a complete stack memorization would find the memory work here less onerous and the split completely undetectable. But, like I said above, once I knew Mnemonica cold splitting on the basis of this has superseded all other very deceptive options.

Les