Listener No. 4378: Present Day By Horvendile

[Contrarian]

I'm surprised that there isn't a thread up for this yet. (Apologies if there is one)

I started on it this afternoon, having only returned to the UK this morning.

Just a couple of loose ends to tie up, but most of it was pretty straightforward.

I loved the idea of including the code-square within the grid itself.

Thanks Horvendile.

[TheBear69]

This probably will reduce the all-correct list...I doubt John Green will have many entries to check, but will be quite a chore for him for the ones he must check.

I may be wrong but I think there's an unfortunate ambiguity at the theme word for 1d. One possibility is more obscure but is truly thematic. But the symmetrically opposite theme word in the last column opens the door for a more common word that is thematic in the way the latter is.

[TheBear69]

On further thought, I suppose the word in the last column is actually thematic per se, so there really is no ambiguity.

Thanks Horvendile! I have a fondness for Playfair-based puzzles.

[fyellin]

Is there a way to determine the Playfair key without using computing power?

I feel sort of guilty for finding the key using brute force. Unfortunately, Playfair is particularly amenable to brute force.

[Contrarian]

I didn't use any brute force techniques. I just used a bit of logic to get going, and then explored a few possibilities suggested by the title.

[fyellin]

@TheBear69: I was also concerned about the unclued in the last column; it seemed to open up the realm of possibilities too far. But then I checked it in the BRB, and was reminded why it was totally apt.

@Contrarian: I would love to hear from Horvendile what was involved in constructing this puzzle. I agree that the idea of including the code-square itself, encoded, was brilliant.

[jim360]

It seemed that if you got the right answers early on determining the full Playfair square was possible really quite quickly. And then after that there was just the small matter of decoding and encoding 60-odd clues a few times. The small, three- to four-hour matter. Quite a drag, that.

The conception is certainly brilliant, and I shudder to imagine the effort that went into setting this -- not least because of the need to make sure it *was* solvable fairly. A debut setter to boot.

[AHearer]

Yes, a few entries were very helpful in sorting things out -- unfortunately, these were amongst those that took me longer to solve. I still needed to explore a few guesses, though. As jim360 says, encoding the whole lot having solved it was a bit of a chore, and for JEG's sake I hope that TheBear69's prediction of the number of entries is correct. Indeed an impressive construction, and I hope we'll be treated to a setter's blog.

Season's greetings to all.

[olichant]

I have to say, I found this a bit of a slog. Very clever, though - I guess if you have to do a playfair (and they're such annoying things, at least in my opinion) then this puzzle is the pinnacle of its kind. Certainly, it forced me to spend quite a lot of time figuring out how the encoding had to work. Really impressive construction - it must have taken an age.

[Scorpius]

I was a bit mystified at first, but once I drew a few logical inferences from some of my answers, a sudden flash of inspiration enabled me to construct the Playfair grid. I didn't mind the subsequent encoding, but I did find getting the unclued entries a bit tedious. One of the clues to a very significantly placed answer has two possible answers, which I found a tad irksome.
I don't know what ambiguity The Bear has in mind for 1d. Out of forty theoretical possibilities I found only one that fitted the grid. On the other hand I found three that would fit its symmetrical partner. I hope I've picked the right one.

[s_pugh]

Wow – that was tough. But to my (admittedly simple) mind I cannot for the life of me see how you could complete this without access to computing power. Is that really in the spirit of the Listener?

Was it just me or were the across clues very tame compared to the downs? I cold-solved all bar two of the clued across entries, but had to back-solve rather more of the downs.

A great challenge which provided a welcome distraction from the scenes of sodden chaos outside my window yesterday! Thanks Horvendile.

[Scorpius]

S_pugh, my understanding is that the editors of the Listener solve the puzzles without electronic aids. I am among the mere mortals who do use aids otherwise I'd still be solving this in two weeks. Having said that, I don't think computing power is necessary to crack the code.

And yes, I agree with you about the downs. I found them far harder than the acrosses; I got two-thirds of the latter on first reading.

[jim360]

Just discovered in time that I'd got one of the unclued entries wrong -- this is a puzzle that just screams "trying to trip you up" at anyone looking for an all-correct year, with so much care required in checking answers. Going to go over it all with a fine tooth-comb before submission, although I don't have a 52/52 on the line thank goodness.

[Scorpius]

Jim, why not use Crossword Man's Playfair Cipher tool on the internet to check your entries? If you enter the key to create the Playfair grid you can then encrypt each answer in turn and check them against your own.

[jim360]

Thanks for the suggestion, although I sort of implicitly meant "with technology's help" in my initial post. Anyhow I did go through it all and found one error that needed fixing.

[tilbee]

Late to this to yesterday afternoon and only just struggled over the finishing line. Unlike some others who found the derivation of the code word/phrase relatively "straightforward" I struggled with this for quite some time, The more datapoints I had the more I tried to overcomplicate it, and it was more by luck than judgement that I finally come to this.

Final step was 8d. I am sure someone can advise me the setters' guidance on how many unches are allowed in a 4 letter answer, when the checked letters are actually encoded !

I concur with Scorpius's recommendation; this is a tool I found whilst solving a Ferret Matrix related puzzle in the Magpie a little while back which required multiple levels of Playfair encoding / decoding and certainly proved very useful.

Certainly an amazing construction but fun ? Perhaps the joy was more experienced in the satisfaction in completing the final (and certainly one of the toughest Listener puzzles of the year. Thanks in any case to Horvendile for the challenge.

[tilbee]

On another note does anyone else have the same issues as myself with the AB site ? Using IE it is now for me totally unusable since it permanently locks up (hence fewer recent posts). I managed to get my post out today using Google Chrome, but still much a slower response than you can type (CPU utilisation is not exceptionally high) - hence also some typos ! Any suggestions are welcome.

[jim360]

Nope, 'fraid not. Sure there's not a problem with your computer -- bit old, perhaps?

[tilbee]

Yes Jim must be all of 2 years old. If we encountered the same with a car or white goods purchase we would rightly be outraged, but it seems for electronic goods we are expected to accept the "design for obsolescence" or probably closer to the mark the gradual entropy of the underlying software. Ho hum, the price of progress (?) I guess.

[jim360]

Hmm... At two years old there shouldn't be a problem just based on age. Without looking at it myself hard to say what's going wrong. At any rate, I haven't noticed a problem with AB across the various computers/ browsers I've used recently.

[emcee]

Spent the evening deducing the codeword. I had a page full of things like C R dot = E dot S (my notation) but it all came out successfully without the use of a PC -- and was quite an enjoyable logical puzzle.

Anyone that has used a PC to solve it may well like to try the codebreaking exercise as it's pretty satisfying when the codeword comes out.

John Green will be kept busy methinks.

Thanks, Horvendile, for a stiff but enjoyable challenge.