For me the sheer elegance of the ZENITH STACK is a thing of beauty.

For those not already familiar with it, it is a sequence of 25 ESP cards (5 occurrences of each of the 5 ESP symbols). With normal playing cards, each is unique; so it is possible to construct a sequence whereby knowing any card tells you the next card (eg Stebbins, or any memorised sequence). We take this for granted, but the same is not possible when there are duplicates, as in an ESP deck. BUT it is possible to know the next card when you know the preceding TWO cards. Others (and Doug himself actually) have constructed such stacks before, but the rules were pretty complicated. With the ZENITH STACK, it is hard (for me) to see how further improvement would be possible.

The algorithm consists of just a handful of very simple calculations. Doug describes these in mathematical terms (for it is mathematical relationship).


For those familiar with the Zenith stack already -
I find it helps to visualise the symbols as a clock face (with just 5 equally spaced positions. The star (5) is at the top (12 on a normal clock).
Counting 4 clockwise (forwards) is therefore the same as counting 1 backwards. I find this very easy to visualise - and it means you never need to adjust for being outside the range 1-5.
I think of starting on the position of card A, then card B being an instruction of how many spaces to move forwards/backwards. This means each shape (when on card B) equates to exactly one rule that is always consistent. This simplifies things even further for two of the shapes. (This should make sense to those in the know!)
I hasten to add that Zenith is already brilliant - and simple! This visualisation makes it (for me) even simpler.

I love that type of work.

Are there around other sources of good effects for ESP stacks?