Shave and a haircut (base 5) generic any stack
Shave and a Haircut "Two Bits"

This thread is the same as my other Shave and a Haircut (base 6) thread except this post multiplies by 15 and multiplies by 5 to get the position of the second spy card.

See the base 6 method especially for the rounding corner technique:

https://themagiccafe.com/forums/viewtopi......forum=99

The base 6 method could not utilize the value 0 (only the values 1, 2, 3). I have developed a new mental algorithm that allows the value 0 in conjunction with this base 5 method. Normally with a base 5 method there would need to be five cards dealt. We will use six cards dealt and the base 5 method which will simplify a few things vs the base 6 method:

Six cards dealt and Base 5 benefits:
1. Simplifies the math (multiplying by 5 is simpler than multiplying by 6).
2. There are no outliers therefore no need for eight mnemonic stories that were required when using base 6.
3. Eliminates the need for minus 1

On your stack round the corners appropriately everywhere you see a 1, 2, or 3:

xxx01xxx02xxx03xxx11xxx12xxx13
xxx21xxx22xxx23xxx3132

Note that the x represents a non-spy card.
Note that the 3 "0" cards will look just like an x card ie: not marked, but more about that a little later, it's simple.

Note that since six cards are dealt there will normally be a two spy card pair together amongst the six. Therefore the algorithm is: The first card marked value is multiplied by 15. Multiply the second card marked value by 5 and add that result to the first result.

Example: the magician sees xxx23x therefore the calculation is 2 times 15 equals 30. Then 3 times five equals 15. Then add 30 to 15 giving 45 which is the stack position of the second spy card of the pair.

There is an issue with the first three pairs
Because the value zero (first card of these pairs) is not marked the magician must think a little differently to recognize these standalone spy cards (the second card of these pairs will look like a standalone marked card).
The first card of these pairs (the "0" card will look just like an x card).

Here is how to recognize the situation:
If the magician sees two spy together among the six then those 2 cards are used to do the normal calculation (to get the position within the mem stack of the paired second spy card). If however there are no marked cards together among the six cards dealt then the magician treats the standalone marked card simply by multiplying its marked card value by 5 to get its position within the mem stack. It's that simple.

Note that 32 calculates to position 55 but the magician simply knows that it is position 52.

If the magician sees xxx313 then use just the 31 to normally calculate position 50 for the card marked as "1" (same as normal calculation, just ignore the second 3).

Marking the spy cards:
This is a generic encoding method for ANY memorized stack using just two bits (two corners). Note that on a spy card we can round (widen) the upper right corner only, the upper left corner only, or both the upper right corner and the upper left corner (and of course their diagonally opposite corners, but the magician only looks at the top two corners).

That is three values that can be encoded ie: 1, 2, and 3. Use the 7 mm slot on the corner rounder device:

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Of the six cards dealt if only card number one and card number 6 are marked then always mentally use the sixth card and multiply it by 5 to get its position within your memorized stack (never use standalone card number one because there is a situation 2xxxx1 where you will get the wrong result, whereas you will always get the correct result by using the 6th card when you have unmarked cards in positions two through five of the six cards dealt).

Reminder that if the magician sees marked card values of 32 (3 followed immediately by 2) together anywhere among the six cards then knows that means 52.

I used this new algorithm with blank back cards at a local magic club. Because I was about 10 ft away from each person (but I could easily see the top two corners of each card) they didn't have a clue, they thought it was some kind of electronics!