The Gilbreath Principle is a strong, powerful, and versatile utility in magic. However, to many it is confusing. In this post I will explain concept and show you how to do a Gilbreath Shuffle.
In 1958 Norman L. Gilbreath published his discovery in The Linking Ring magazine. In there he described a utility that allowed magicians to hand a deck of cards to a participant and have them shuffle. Yet he was still able to achieve miracles.
Martin Gardner saw the power of this, writing about the Gilbreath Principle in a 1959 edition of Mathematical Games for Scientific America. From here it gained some popularity within the magic community, but not enough.
Since this time many have toyed with the idea, and published some work on the matter. Potentially the most famous of which is Max Maven.
Max Maven has done much to popularise the theory within magicians, releasing several effects such as Zenvelopes and The Mockingbird from his Videomind Series.
The Gilbreath Principle clearly has a lasting power with so many high profile magicians being interested in it and working on routines utilising it. So why is it not more widely used in the community?
Is it because many think it is too complicated? And they do not know how to do a Gilbreath Shuffle? Once you understand the basics of the principle you will be able to set up your own shuffles for participants to perform and you will pull off miracles.
How does the Gilbreath Principle work?
Before we continue it is essential for your understanding of how to do a Gilbreath Shuffle for you to appreciate how it works.
One of the most concise explanations I have ever seen is as follows:
“The pushing of a entity into the reverse of itself.”
This is a fabulous description; if you know how the Gilbreath Principle works already. Otherwise it means nothing to you and is useless.
Instead I will give you an example that you can see at home. Take a red and black poker chip and create a stack with the black one on the bottom. Place another black chip in the stack and we can guarantee the top two chips will always be different colours.
You can see this in the following diagram:
This is the fundamental underpinning, but not everything. Clearly a one item stack is not enough to have participants genuinely shuffle. But we can increase the stack size further.
As previously stated you will need the entities to be the reverse of themselves. In this case with the chips have one stack with a black on the bottom and the other with a red.
When shuffling these two stacks together we can guarantee top two chips will be a red and black. As will the bottom two.
This simplistic demonstration is where most stop. It is what has lead to the majority of publications on the Gilbreath Principle being Out of this World style routines. All you need do is look at the Conjuring Art’s database on the Gilbreath Principle to see just how many there are.
The power of the Gilbreath Principle does not stop there though. We will absolutely take it one step further, beyond simple two factor repeating patterns.
Create two stacks of playing cards, one being Ace to King and the other King to Ace. When these are shuffled together we can guarantee the top 13 cards will contain no repeating cards.
But how does this work? You may be able to visually see this happen, but understanding it is complicated. Take our previous stack of Ace through to King and imagine it. Picture taking another King and place it anywhere in this stack it would push the original down one position.
This therefore means the top thirteen cards still contain Ace through to King.
Imagine then taking a new Queen. Push it in the stack anywhere below the previously inserted King. It will also push the original Queen down one place.
Once again the top 13 cards still contain an Ace to King.
This trend continues no matter what as we increase the cards, as long as the two stacks are reverse entities of each other.
That is essentially how to do a Gilbreath Shuffle. Take two entities, have them be the reverse of each other, and riffle shuffle them together.
What other Gilbreath Shuffles are there?
Most explanations of the Gilbreath Principle leave you there. The problem is that not every participant can do a riffle shuffle, so you need a few more shuffles in your arsenal that achieve the same result.
The faro shuffle is the most obvious one. Simply cutting the deck and having the participant push the two packets into each other in their hands. Some may think this is an impossibility, that it is less likely than a riffle shuffle from a participant. However when filming Inside with Dee Christopher I was showing some Gilbreath based material to his girlfriend. As it turned out her standard shuffle was a faro.
Another fabulous shuffle is the Rosetta Shuffle. An independent creation on the part of Lennart Green released initially in Green Magic Vol. 4 (2003). It was actually first published by Charles Nyquist and Jack McMillen as part of The San Francisco Shuffle in a 1949 edition of Genii. The idea is to take two stacks of cards, place them on the table and spin them in the middle on top, so that they fan out like a rosette. You then push these two packs together. It simulates a riffle shuffle, looks chaotic, and is easily achieved by a spectator.
A different style of shuffle that may appear just as chaotic is a ribbon spread shuffle. Take the two stacks of cards and spread them next to each other in a ribbon spread. By pushing them together we maintain the original stacks’ relative order, just as we need.
How to do a Gilbreath Shuffle
In summary, take two entities that are the reverse of each other and shuffle them together in a manner that maintains the original entities’ relative order. The riffle shuffle is the most widely utilised, but there are many others than can be used.
If you would like to learn more about the Gilbreath Principle you can purchase my book Breath.