I appreciate your defense of the good professor. I really do. But please! Are you seriously suggesting that a Stanford professor, who isn’t exactly a rookie when it comes to magic and to research in general, failed to research the literature before publishing in this case and was totally unaware of a two-volume set of books on the very topic he addresses in three chapters of his book? I don’t buy it. Besides, I believe Chris knows how to read an email.

I was just pointing out that this is a "Chris says-that Ron says-that Persi says" statement........which is getting a bit far from the horses mouth.

Without Diaconis's response (which isn't at all likely based on the whole "animals" thing), this remains postulating, sans any real facts.

BUT, if I wanted to pursue information about de Bruijn cycles, I'd without hesitation go buy all of Leo's books, as I'd like to think most readers of this thread would as well.

Information in this thread (and elsewhere) has highlighted Boudreau's work on de Bruijn cycles as being more complete (and original) than the work presented in the Diaconis book.

I came across this thread, downloaded the book to my Kindle, and have been devouring it over the last few days. Great stuff!

I'm having trouble with the authors' take on Charles Jordan's "Long Distance Mind Reading" however. In the book, they say it should work about 90% of the time. My practice with it yields almost exactly a 50% success rate. It works virtually every other time. Not sure what I'm doing wrong.

A passage in the workings of the trick has me a little confused. The effect is described as: "The way we use this principle now is as follows. A deck of cards is mailed to a friend (or given to a group of spectators while the performer turns away). 'Give the cards a cut, give them a shuffle, then give them another cut and another shuffle, give them a few more cuts. I’m sure you’ll agree that no human can know the name of the top card. Please take this card off, look at it, and remember it. Insert it into the middle of the deck. Give the cards a random cut and another shuffle. Mail the deck back to me.'"

Later, however, in the explanation, they write: "It is best to practice this with cuts followed by one shuffle, then two shuffles."

That second sentence is a little vague, but I take it to mean that when practicing, one should cut a few times, shuffle, have the card selected and returned, then shuffled twice more.

In any case, whether I shuffle the deck twice, have the card selected, and shuffle - or shuffle once, have the card selected, and shuffle twice, it only works about half the time.

If anyone is familiar with the trick and could lend a hand, I would be most thankful.

- Bob

""The way we use this principle now is as follows. A deck of cards is mailed to a friend (or given to a group of spectators while the performer turns away). 'Give the cards a cut, give them a shuffle, then give them another cut and another shuffle, give them a few more cuts. I’m sure you’ll agree that no human can know the name of the top card. Please take this card off, look at it, and remember it. Insert it into the middle of the deck. Give the cards a random cut and another shuffle. Mail the deck back to me.'"

Do that.

I attended a Ron Graham lecture last night and he covered a few items from the book.

http://www.math.ucalgary.ca/files/math/j......2015.pdf

He mentioned that a soft cover edition of the book will be out soon, and that it will contain a number of corrections.

This is one of the best books I've bought in 42 years in magic. And oddly I only stumbled upon it when the Amazon shopping algorithm suggested "other readers who bought XYZ also bought..." I really had low expectations, but it is fantastic for method, history and explanation.

Is the soft cover version of this book out (with corrections)?

One of my all time favorite magic books.

Any link for the soft cover edition please ?

Yelnif 47 Deck
DeBruijn - Aronson - memorized 47 deck:
I just discovered the DeBruijn principle a month ago and am fascinated by it.
My apologies if someone has already come up with the 47 card deck that I will describe below.

DeBruijn 32 sequence:
"11001001110100010101101111100000"
I am using the Aronson stack but the below 47 card technique can be done with any memorized stack or scheme (the first card in Aronson is the JS therefore if you are using say Tamariz then use the first Tamariz card where the JS is below and so on).

The below is correct. I have tested all 32 possible situations and it is working perfectly for the Aronson memorization.

Below uses Aronson first 32 cards (Jack Spades thru 10 Diamonds) then followed again by the Aronson first 15 cards (JS thru 7D) but of course physically in DeBruijn sequence below. Note the "B" in in front of each card name is designating a "hit" ie: a binary "1" card whereas an "R" in front of the card name is designating a binary "0". The "B" cards can be Blue backed and the "R" cards can be Red backed or you can use a "one way" backed deck to accomplish the same thing (the "B" cards oriented correctly and the "R" cards oriented the reverse way).

B8C B3D R5H RAS B7S R8D R2H BAD B7H B7C
RKD B8S R10S R9S RKC B3S R6C B5S RAC BQD
BQH R2D BAH B5D B4H BKH B4D R7D R3H R5C
RJS R10D

Add a duplicate set of the first 15 cards to the bottom of the 32:
B8C B3D R5H RAS B7S R8D R2H BAD B7H B7C
RKD B8S R10S R9S RKC

This makes the deck look more substantial (47 cards). This will create one rule breaker: binary value of 17 could be the three of Spades or it could be the eight of Clubs therefore if the total is 17 the magician should do an equivoc statement such as "your card isn't the eight of clubs is it?" and if they say "no" you say "I thought it wasn't, it's the three of Spades".

The reason why there is only one "rule breaker" instead of 3 or 4 is that I realized that the 15th card is at the end of three binary "0"s and that this wraps nicely to the first card that is expecting four "0"s from the tail end of the first 32 cards. Therefore I use the first 15 cards again instead of the first 20 which would yield a 52 card deck but would cause more "rule breakers".

Example: If the five cards dealt onto a horizontal row are B R B B R then mentally calculate 1+0+4+8+0=13 which means the fifth card dealt is the Aronson 2 of Diamonds (you know this instantly because you have the Aronson numbers and cards memorized).

The one negative to my 47 card deck is that you do have 15 duplicate cards but they are not physically close to each other so unlikely to be detected. I do like a more normal looking size deck rather than a skinny 32 card deck.

What to ya'll think?

If you are using a different memorized stack then the DeBruijn 47 card sequence is (by your deck postition):
Note: the "B" cards are binary "1", the rest are binary "0".
B16 B24 12 6 B19 9 4 B18 B25 B28
14 B23 11 5 2 B17 8 B20 10 B21
B26 13 B22 B27 B29 B30 B31 15 7 3
1 32
B16 B24 12 6 B19 9 4 B18 B25 B28
14 B23 11 5 2

To clarify - In the above sequence:
the first DeBruijn card would be your 16th card
the second DeBruijn card would be your 24th card
the third DeBruijn card would be your 12th card
the fourth DeBruijn card would be your 6th card
the fifth DeBruijn card would be your 19th card
...
and so on.

October 8, 2018 Larry Finley starting from scratch created a 6 bit non-repeating de Bruijn sequence in a 52 bit circular cycle:
0 0 0 0 0 0 1 1 1 1 1 1
0 0 0 1 1 0 1 0 0 0 1
0 0 1 1 0 0 1 0 1 1 1
0 0 1 1 1 0 1 1 0 1 1 1 1
0 1 0 1 1

And if you're interested in ENTERTAINING with math miracles, check out MATHEMATICAL WIZARDRY.

Forgive the above plug - some asked me to do so because - the feeling was that most did not know about my book. Incidentally, Persi and I hung out a bit decades ago in NYC.