Search found 1091 matches
- Wed 20 Jan, 2021 11:34 pm
- Forum: Puzzle Competitions
- Topic: Division D 2020-21
- Replies: 43
- Views: 7304
Re: Division D 2020-21
Hi Adam - I forgot to enter - is it worth bothering to send answers in late anyway?
- Tue 19 Jan, 2021 12:46 pm
- Forum: Puzzle Competitions
- Topic: 2021 WPF Sudoku and Puzzle GPs
- Replies: 48
- Views: 3027
Re: 2021 WPF Sudoku and Puzzle GPs
I didn’t have a go at extended extra regions during time, and was pleased that I didn’t. It reminded me of why I lost interest in the GP last year. There seems to be a growing trend of puzzles that I find hard because they are fiddly and there is no sense of flow to my solve - actually I'm finding t...
- Fri 15 Jan, 2021 3:35 pm
- Forum: Puzzle Competitions
- Topic: 2021 WPF Sudoku and Puzzle GPs
- Replies: 48
- Views: 3027
Re: 2021 WPF Sudoku and Puzzle GPs
Some other solving tips: Diagonal consecutive: when using the negative constraint, bear in mind that if you have a 5 in a cell, then yes that rules out 4,6 in cells touching at a corner, but it can still be a 5. I often do that by mistake as the equivalent heuristic for consecutive sudoku would rule...
- Fri 15 Jan, 2021 11:53 am
- Forum: Puzzle Competitions
- Topic: Asian Sudoku Championship 2021
- Replies: 2
- Views: 507
Asian Sudoku Championship 2021
See this message I was sent for details. The ASC is usually an on-site competition happening at around January time - for example last year was organised by Rishi Puri in India - but this time round it's being hosted online so everyone can partake. Dear all, Due to the worldwide pandemic, the 5th As...
- Fri 15 Jan, 2021 11:44 am
- Forum: Puzzle Competitions
- Topic: 2021 WPF Sudoku and Puzzle GPs
- Replies: 48
- Views: 3027
Re: 2021 WPF Sudoku and Puzzle GPs
Yes sadly full rank is one of the tedious types where you need to know "the trick". They all solve in roughly the same way: Ranks 1-4: digit closest to the edge is a 1 Ranks 5-8: digit closest to the edge is a 2 ... All the way down to Ranks 33-36, where the digit closest to the edge is a 9. Then yo...
- Fri 01 Jan, 2021 4:57 pm
- Forum: Puzzle Competitions
- Topic: 2021 WPF Sudoku and Puzzle GPs
- Replies: 48
- Views: 3027
2021 WPF Sudoku and Puzzle GPs
Lets experiment with a combined thread this year :) https://gp.worldpuzzle.org The schedules have been published for 2021. In general there is one competition every fortnight, alternating Sudoku and Puzzles. [Note the slight break in that schedule for June however!] The first of the 2021 competition...
- Wed 23 Dec, 2020 10:14 am
- Forum: General Puzzle Discussions
- Topic: 8x8 Sudoku variant - Help required please
- Replies: 5
- Views: 1176
Re: 8x8 Sudoku variant - Help required please
So the first point sounds like a Latin square (just rows and columns) rather than sudoku (which would also gave regions. Since writing down 12345678 down the top left bottom right diagonal works fine, start with a blank grid, add in that diagonal, and then fill out the rest of the grid using sudoku ...
- Sat 12 Dec, 2020 11:46 pm
- Forum: Puzzle Competitions
- Topic: Division C 2020-2021
- Replies: 15
- Views: 3442
Re: Division C 2020-2021
Glad I came back to this thread - the document itself says 11th - 14th November so I thought i was too late. Time enough to read up on these variations again!
- Sat 12 Dec, 2020 3:00 pm
- Forum: General Puzzle Discussions
- Topic: Thermo miracle methods
- Replies: 6
- Views: 1235
Re: Thermo miracle methods
My bad, I’m being a bit lax with the dihedral symmetries. There are normally a total of 8 (4x multiples of 90 degree rotations, 4 more reflections in the | - / \ axes) but I was probably getting a bit excited given that a 180 rotation in that grid is actually the same thing as a digit permutation (1...
- Fri 11 Dec, 2020 10:50 pm
- Forum: General Puzzle Discussions
- Topic: Thermo miracle methods
- Replies: 6
- Views: 1235
Re: Thermo miracle methods
Every solution to the anti-knight no touch constraint looks something like this: Screen Shot 2020-12-11 at 22.40.46.png All you need to do is permute the numbers attached to each colour, and possibly rotate by 90 degrees, until you find something that works. To suggest there was some "intended proce...
- Fri 11 Dec, 2020 10:27 am
- Forum: General Puzzle Discussions
- Topic: Thermo miracle methods
- Replies: 6
- Views: 1235
Re: Thermo miracle methods
The trick with “miracle” aka anti-knight combined with no touch constraint is that there is one solution, up to dihedral symmetries of the grid (reflections/rotations) and permutations of the symbols (eg swapping all the 1s with all the 3s). To be honest, despite the hype, I think that “miracle” puz...
- Sat 05 Dec, 2020 10:46 am
- Forum: General Puzzle Discussions
- Topic: Trying to make a knight's-move puzzle with minimal rules/hints
- Replies: 7
- Views: 1369
Re: Trying to make a knight's-move puzzle with minimal rules/hints
I’m not sure I understand the constraint properly (perhaps you could draw a picture to demonstrate what you mean?) - but I would add that unless the constraint gives some information about digits relative to one another (like consecutive) then 8 will always be the lower bound for clues. To see this,...
- Tue 01 Dec, 2020 6:30 pm
- Forum: General Puzzle Discussions
- Topic: Printing puzzles for contests
- Replies: 3
- Views: 1133
Re: Printing puzzles for contests
It’s fair to say there are definitely people who are not just using paint to do things like the GP, but making use of online solving interfaces. When challenged, these people tend to say: (A) there’s an initial time cost in manually drawing up the puzzles so it’s not clear it’s any kind of advantage...
- Sun 29 Nov, 2020 10:45 pm
- Forum: General Puzzle Discussions
- Topic: Some puzzles for your solving pleasure
- Replies: 27
- Views: 16606
Re: Some puzzles for your solving pleasure
I enjoyed these a lot Sam, thanks for posting - really top notch quality, and a satisfying level of difficulty for sure. I'm fairly certain I overthought a couple of them with suggestive patterns though 

- Sat 14 Nov, 2020 8:00 pm
- Forum: Puzzle Competitions
- Topic: Division D 2020-21
- Replies: 43
- Views: 7304
Re: Division D 2020-21
Thanks Adam for organising, and Freddie for the puzzles, an enjoyable set!
- Tue 10 Nov, 2020 11:30 am
- Forum: Puzzle Competitions
- Topic: Notation for Sudoku
- Replies: 4
- Views: 1344
Re: Notation for Sudoku
I’m not sure this will catch on. The main criticism i have is is to do with the indexing of cells. I much prefer R5C3 as opposed to 5c. Maybe that’s just what I’m used to. I also think you need to bear in mind that trying to formalise logical placements using a symbolic language is going to run into...
- Sat 24 Oct, 2020 9:48 am
- Forum: Puzzle Competitions
- Topic: Divisions A and B 2020-2021
- Replies: 36
- Views: 3886
Re: Divisions A and B 2020-2021
Hmmm...I have to say I’d not considered the mobile aspect. I tried puzzle duel on my phone and it did feel like a better experience compared to laptop/mouse. I suspect that’s because I’ve got no baseline experience to compare to on mobile. I would say that, without any exaggeration, the sudoku on pu...
- Wed 21 Oct, 2020 2:29 pm
- Forum: Puzzle Competitions
- Topic: Divisions A and B 2020-2021
- Replies: 36
- Views: 3886
Re: Divisions A and B 2020-2021
Hi I’ve just tried to use Puzzle Duel on a tablet and a laptop and it seemed fine. Is that because it was a loop puzzle? Where is the issue? Try a shading puzzle - awkward but doable, there’s no dragging so you have to click every cell. Definitely favours those with good mouse work. Try an object p...
- Mon 19 Oct, 2020 12:03 am
- Forum: Puzzle Competitions
- Topic: Divisions A and B 2020-2021
- Replies: 36
- Views: 3886
Re: Divisions A and B 2020-2021
On the subject of LMI (and here I'm leaving aside my personal grievances) - from a competition point of view it is not clear what is going to happen next year when Flash becomes totally obsolete. They may not even have a functioning competition engine!
- Sun 18 Oct, 2020 11:47 pm
- Forum: Puzzle Competitions
- Topic: Divisions A and B 2020-2021
- Replies: 36
- Views: 3886
Re: Divisions A and B 2020-2021
I'm not taking this super-seriously (for example I probably won't take part in the LMI contests), so by all means please don't act just on the basis of me, but... The Puzzle Duel interface is mouse only, and it is singularly awful because of that. I think I'm OK at it and probably have a slight adva...
- Sun 18 Oct, 2020 11:40 pm
- Forum: Puzzle Competitions
- Topic: Division D 2020-21
- Replies: 43
- Views: 7304
Re: Division D 2020-21 Round 1
Haha - I'm fascinated by the idea of marginal gains to try and get on the same planet as Ken :) In the sudoku world many of the ultra quick speed solvers are Chinese. One theory I had is: given that chinese characters are an order of magnitude or two more complex than those of the latin alphabet, th...
- Fri 16 Oct, 2020 10:04 pm
- Forum: Puzzle Competitions
- Topic: Division D 2020-21
- Replies: 43
- Views: 7304
Re: Division D 2020-21 Round 1
A couple of words on my times: (which are entirely consistent with how I have previously approached competitions and test solving alike) Although the instructions to fillomino tell you to place a number in each cell, most of the time I will instead draw borders to identify regions of connected cells...
- Tue 22 Sep, 2020 9:48 am
- Forum: Puzzle (incl. Sudoku) Rules & Tips
- Topic: Fillomino
- Replies: 5
- Views: 2837
Re: Fillomino
Hello, as part of a beginner series I have posted a set of Fillominos - including a guide to solving techniques - on my blog a short while ago, and I am happy to share them here: https://hausigel.de/blog/2020/06/20/classics-collection-fillomino/ https://www.hausigel.de/blogdata/cc_6/Fillomino.pdf T...
- Tue 08 Sep, 2020 11:18 pm
- Forum: Puzzle Competitions
- Topic: UK Puzzle League 2020-2021
- Replies: 10
- Views: 4386
Re: UK Puzzle League 2020-2021
Can we register our interest here as well? If so, I’d like to register my interest, although I’d caveat that I have more interest currently in the UK set puzzles than I do in the other open competitions.
Well done on showing some much needed initiative Adam
Well done on showing some much needed initiative Adam

- Tue 04 Aug, 2020 5:33 pm
- Forum: Puzzle Competitions
- Topic: Puzzles at the Mind Sports Olympiad in London on Sunday
- Replies: 45
- Views: 62455
Re: Puzzles at the Mind Sports Olympiad in London on Sunday
Thought I’d comment briefly given I dipped my ties back into competition - I think MSO is well worth supporting. Turnout was a bit low, perhaps due to people not really knowing how to work the Estonian site, but perhaps also due to lack of publicity. I’m sorry to see David C had issues - basically y...