UK Puzzle Association

I think I can be confident in that it was unanimously found to be a very tough set. It's understandable for the organizers to up the difficulty from the previous series (given the general improvement in speed) but it was quite overdone.

I’ve constructed a Nurikabe battleships, if anyone wants to try. Probably quite tough (80 points?): https://git.io/JYeyw

Yeah, David definitely has a chance to claim 4th/5th place. 3rd is still theoretically possible but he’d have to solve at an absolutely blazing pace!

Preliminary results for round 3:

19. Sam Cappleman-Lynes 602.2
23. Tom Collyer 564
40. Freddie Hand 504

An unfortunate error from Sam, though one which costed only a single place. This felt like a relatively easier round, with a high number of scores in the low 500's.

Both are unique if you clarify a certain number of mines. Triangular with 6, socially distanced with 4.

Are you going to penalise errors, and if so, by what amount? Due to the nature of the interface it is very possible to register an error just due to an edge/digit/other object having been missed and not an actual solving mistake; it might be possible to consider an ‘honesty error’ system here.

I re-attempted the SPOLICY’s and indeed they presented little trouble to me (I don’t think I benefited from recollection). It might have been that I’d managed to convince myself of a particular incorrect placement in both puzzles.

I think you may have got lucky with the SPOLICY’s. My intuition ended up failing me so I had to go for a full casebash, which wasn’t particularly enjoyable. EKBM took 4 minutes on each of them though so I don’t feel quite as bad about it.

Promising results for the UK again! Unfortunately that was a horrible round for me; submitted 709 points worth of puzzles but had three errors, including one on the 105-point yinyang. Burnt a bit too much time on the puzzles without a clear logical path: the first arithmetic square and the two SPOLI...

I suppose the circle in R4C6 is supposed to be white, not black.

Preliminary results for round 2 of the sudoku GP: 38. Freddie Hand 482 41. Sam Cappleman-Lynes 481 78. Tom Collyer 372 Tantan and Tiit well clear of the field, as well as Tomasz Skrzypczak (their first appearance in the top 3, I believe?). That was a fairly bumpy round for me so somewhat surprised w...

Yep, that’s all the standard Masyu you can do. But you know that R6C6 can’t go up and left or down and right (by normal Masyu), and going up and right will leave a cell empty, so it must go down and left.

For the first slitherlink, the 31 pattern gives two x’s and a segment. That causes some diagonal interactions. For the Masyu (all cells), after a bit of standard Masyu, consider R6C6. You should be able to determine its orientation. For the third slitherlink, the key deduction is loop avoidance; you...

I meant the classic slitherlink - I heard from some people that the first took longer than either of the other two - but come to think of it, I did struggle with the first S & W. Second one felt much easier to me.

I’d be interested to know which puzzles people had difficulty with; slitherlink 1 and 3 could have caused trouble (13 pattern/diagonal interactions) and the parity deduction in the first regional yajilin too (must be an even number of shaded cells so unclued region has one shaded). But the others se...

Yeah, this was a surprisingly tricky round. There were a few low-pointer puzzles with relatively advanced deductions, most notably the first slitherlink and regional yajilin.

I'm not sure that this is a valid argument because puzzling events are almost exclusively hand-crafted. And besides there are plenty of puzzle genres in which I have basically never seen a computer-generated puzzle.

Tip 8: make sure not to misspell words, taking particular care if they are not English. It can be a cause of much frustration!

They’re pretty inconsistent with publishing official results; sometimes they’re published by Thursday but one time they were still preliminary after two weeks! Darts is mostly just educated guessing, as Tom says. You can use certain observations to narrow down the search space (bounding, parity, etc...

I think it’s probably best to wait for official results to be published before updating the league table. Should be released by next Monday.

Thanks Tom. I suspect my lead will be short-lived (since Yanzhe was penalized for inputting the codes for 4 and 5 in the *right* order) but hoping to hang on to second. A strong showing for the UK indeed! We may be brought back down to earth by the subsequent non-numbers heavy round, but hopefully t...

Yes, I found the dissection in the example was almost completely resolvable using essentially only domino-type logic (though of course invoking the parity properties of the path). Identifying the ends of the path only comes into play later on, both of which are forced by the fact that two adjacent d...

The main issue I see is that with the anti-knight constraint there is no need for complete cluing, so the usual tricks may not be applicable. Then again it could be just be a large and fairly straightforward puzzle as you say, similar to last year’s Easy as Japanese Railway.

The instructions booklet for round 1 of the puzzle GP is our at https://gp.worldpuzzle.org/sites/default/files/Puzzles/2021/2021_PuzzleRound1_IB.pdf Looks to be a fairly unorthodox round, with a high concentration of maths/arithmetic based puzzles, around 75%. Of these the anti-knight products is cl...

That’s a pretty impressive time Sam! I was barely able to beat you with a time of 6m 45s (though I was copying out the puzzles as well as doing them :p)