

Nevbar1 New user 3 Posts 
Hi all, Just wondering if anyone can explain the mathematics of Bob Hummer's Little Stranger trick (aka the pocket trick). I understand the mechanics of the trick  just trying to fathom the mathematics. I can see some sort of connection/logic to the key numbers used in the trick but just can't seem to gain a true understanding of WHY the trick works. Has anyone unpacked this trick or found a site/paper that does?

saxonia Regular user 120 Posts 
In the first round, let B be the number of black cards that go to the left pocket, so 15B cards go to the right.
In the second round, the spectator takes 15B cards. This means that 52(15B) remain. Hence, when we know the number of remaining cards (blacks and reds taken together), we can easily find out B. So, from the number of remaining cards alltogether we can already conclude the number of cards in the hip pockets. Once we know how many reds and blacks are in the hip pockets, and we know how many blacks and reds are in the remaining stack, we know how many reds and how many blacks are missing. Those are in the pants pockets. 
federico luduena Loyal user Buenos Aires, ARG 203 Posts 
Barrie Richardson published a very interesting version in Act Two. It uses a bag of marbles and it's called "Marble Memories" (p150).

Nevbar1 New user 3 Posts 
Quote: Thanks for the response. I was more intrigued with piles c and d. I couldn't see how the counting identified the number of colours in each pile. However, a bit of a quite moment during this lock down and a tiny dose of algebra has now sorted it. Thanks for your response.
On Mar 27, 2020, saxonia wrote: 
Nevbar1 New user 3 Posts 
Quote: Thanks for the response. I'll look this up.
On Mar 29, 2020, federico luduena wrote: 
Andy Moss Special user 707 Posts 
This is a very clever mentalist effect. It reminds me a little of an effect by Martin Gardiner (Three commodities?) which used a similar approach. I know that Bob Hummer was a friend of his.
The only thing that I would quite like to do is to find a means where we might have the spectator take out marbles from a bag or a box. Say that there are thirty marbles in the bag. (We could get away with only twenty six if we use thirteen black and thirteen transparent marbles). We could then make the necessary peek to ascertain the two pieces of information that we need to make the calculations. But how do we make the peek very subtle? Perhaps a small paper prescription bag with a transparent window flap at the back? Will have to give it some more thought...... 
Andy Moss Special user 707 Posts 
Martin Gardner not Gardiner! (But then you already knew that!)

Andy Moss Special user 707 Posts 
O.K I have given the effect some thought. It seems to me that there are many potential approaches for a binary differentiation.
Firstly we may use tarot cards and utilise the fact that there are cards with a feminine and contrastly cards with a masculine energy. In most cases this energy will be obvious to someone making the discernment since there are female major arcana cards such as Justice, Strength, Empress etc and also female personality cards. There are male major arcana cards such as The Hanged Man, The Hermit etc and male personality cards. Thus the binary discernment is no longer colour but is now gender. A second idea is to collect together thirty small objects. Here is a list of objects that I might choose to use. These items are commonly found in most households. Screw, elastic band, paper clip, band aid, pencil shapener, eraser, coin, chess piece, safety pin, piece of candy, washer, pencil stub, metal nut, crayon, ball bearing, clothes peg, hair clip, sugar lump, sink plug chain, pebble, ring, stick, D and D lead figurine, plastic figurine, battery, marble, tiny tin/pill box, game die, key, casino chip. The odd numbered items of the list are metalic and the even numbered items in the list are not. Thus the spectators will grab any fifteen items before being asked to place any that are metalic in their left pocket and so on.....Things have now been made much more subtle and the peek to gain the two pieces of data that we require may now be made openly and boldly. The third idea is to use dominoes. The binary divide in this case would be dominoes that have a blank for at least one of their endings. Thus the spectator grabs any fifteen dominoes and is instructed to make the discernment. This too is very subtle. The advantages of the above ideas is that the spectators will not suspect that there is any preset balance or order within the data array as they might with red and black cards in a normal card deck. It will also be simpler to ascertain the two pieces of data from the items left behind after the filling of the four pockets. That is to say we will not need to look through the deck. We will know at a quick glance. Naturally we will be making our divination and placing our emphasis on the NUMBER of items in each pocket. We will not be placing any emphasis on the binary divide after the placements into the pockets have been made. 
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