Arcadia’s Unrepeatable Offer
A few solvers have asked for a brief blog on how I managed to construct two such Playfairs. Having read the editorial comment in Issue 259 that “Anyone who was astounded that Arcadia came up with Playfair-encoded real words might be disappointed to discover that this is something that is… reasonably feasible for a human-computer team”, I wondered whether it was worth saying anything! However, here are a couple of snippets readers might find useful.
The initial idea came from two sources:
- A Magpie editorial seeming to slightly bemoan the lack of Playfairs, recognising their marmite reputation with solvers;
- the Azed Playfair 2630 of 6 November 2022, in which four of the eight coded entries had double-unches and were just jumbles – which was rather unsatisfying.
So I thought I’d take Azed’s grid and see whether I could create a Playfair where real words encoded into other real words. A little research identified a little-known (I thought) aspect of Playfairs – that any pair of the same letters stayed the same after coding. That seemed to me to make a virtue of double-unches if they had the same letter.
The essence of a good Playfair keyword is a lack of repeated letters, so I looked for the longest heterogram I could find. Then I thought “why not make all the normal entries heterograms as well?” Here Morewords.com proved an invaluable source, allowing me to create a Quinapalus dictionary of heterograms of length 4 to 12. Then I could try filling the grid using a cypher of longer than 12 letters. There aren’t too many! I can’t remember now what shortcuts I used to find the two cyphers COMPUTERNIKS and DOCUMENTARILY, as creating sufficient encoded real words (again, there aren’t that many), but serendipitously I was able to fill the same grid (Azed’s with only a slight tweak) with all bar one of the normal entries in one grid and most in the other being heterograms.
All that remained was the task of creating two sets of clues, one of which consisted almost entirely of heterograms, the other having at least one word with a repeated letter. No computer help was involved there!