WSPC 22: Day 1

On to the first day of competition at the world sudoku championships. I started the day full of excitement, but perhaps not quite with a level of mental sharpness ready to start the competition. 

We’re up to lunch now and I’m licking my wounds; the morning’s solving counts as one of the more chastening experiences I have had in 15+ years of solving. 

I’ll edit in more later, but for now I am at least comforted by the general consensus in the room that it has been hard! Seriously hard! Hard enough to make me wonder whether having a non-zero round represents a good achievement now. I will be even more studiously avoiding anything looking like scores or a leaderboard from now on. That was always going to be the case, but the readjusting of expectations this morning has hit me hard and left me low and disappointed. 

The first round was classics only, and I think the only way to look at things is an acceptance I choked. I got one puzzle done, tried enough twice, convinced myself there was an unresolvable contradiction and from there on in I was making errors left right and centre. 

The rounds after were disappointing in many ways. The second was looking ok, but ended up spending a lot of time on a puzzle without being able to finish it. Round 3 had a combination of 1 and 2’s woes, wasting a large amount of time on a puzzle I was convinced could not have a solution. Round 4 was just hard all round - no contradictions this time, but also not much in the way of puzzles solved either. I think I might have one. 

The morning ended with round 5, a very large samurai sudoku with 14 overlapping grids. Speaking with others this was also very hard, but I finally managed to get a good round under my belt. I’ll claim 11/14 completed grids in the 30 minutes - which is going to be close to my round 1-4 scores combined if there are no errors. Let’s hope not!

As far as the contenders are going, I don’t really have a feel for things. I had a nice chat with the ever-kind Tiit Vunk about the mental side of long distance running - he’s not feeling the pressure too much this year and is instead focussing on enjoying all the puzzles he’s able to solve. I’m not sure many are finishing rounds, or even close to, but performance of the day goes to Kota Morinishi - he got that Samurai out in what I think was 18 minutes. 14 9x9 grids in 18 minutes! And that’s with what felt like the requirement to place numbers in about 8 of them before you could really get going. I think I heard Tantan declare with roughly 5 to go as well, but I think given how things have gone so far I can imagine Kota being an imperious position at the front of the pack. 

On to the afternoon!

WSPC 22: Day 0

So I was hoping to post a bit more earlier today but now I’ll keep it brief. The official arrivals day started pleasantly with breakfast with old friends from Poland on the organising team. It’s like 3 years of madness that have past since we all last met in 2019 washed away - and pretty much references to “last year” throughout the day as people arrived became an agreed standard. 

It was nice to share stories from fellow championship organisers - our efforts date back a few years now to 2014 - but also a little sobering to hear about the impact of the Russian invasion of Ukraine on Poland, particularly with regards to military logistics. Later meeting some of the Japanese team brought tales of longer flight times due to diversions around Russian airspace. This year, there is no Russian presence at the championships as there usually would be, although a good friend from Belarus did manage to make it. These issues of course are far bigger than a puzzle championship, but that doesn’t mean they should not be discussed or shied away from. 

After a walk through some nearby woods in the crisp autumn sunshine, the rest of the day was spent in the hotel greeting a steady stream of arrivals. The UK team is all here now and looking forward to the competition. I’m curious to see how newcomer Jack does at his first competition, and I was pleased to tease Cracking The Cryptic’s Mark Goodliffe that he was probably the most famous person here, with his 500,000+ follows. Probably enough to outdo the likes of Will Shortz, even if he has had cameos on the Simpsons and his I met your mother. 

Perhaps my favourite time of the day was spent well with my good friend of many years now and anlso general all-round Chinese phenomenon Tantan Dai. I’m probably not totally partial here, but I think she is a narrow favourite for the Sudoku title ahead of the likes of Estonia’s Tiit Vunk and serial world champion from Japan Kota Morinishi. Those three are all mind-blowingly talented as well as being really good decent people in a way that it is hard to do justice - whoever comes out on top will be a worthy winner - but this year I’ll be firmly rooting for Tantan!

No surprises in the evenings Q&A - although the team rounds sound like they might be eventful. More to come tomorrow!

WSPC 22: Day -1

So here’s to the revival of detuned radio’s championship reports!  I don't have a laptop with me this year however I’ll see what I can do tapping things out on a phone. I don’t think I’ll be in depth with all the gory details as I once was, and I think I’ll try to be at least somewhat journalistic about proceedings, aiming at an audience who sort of knows what puzzles are but don’t really know what the world championships are all about. 

I am here, finally, in Krakow. About 4 hours late, and sorely missing the company of others I’d hoped to catch this evening who have very sensibly gone to bed. I have sworn many times never to fly Wizz Air again, but I think this time is probably the last. I look forward to an epic fight to claim my rightful €250 when I get back home. 

To set the scene about the championships, I can share some of my day idly spent staring at a phone within the confines of Gatwick airport. 

At both the WSC: https://www.wspc2022.com/wsc and the WPC: https://www.wspc2022.com/wpc there is about as much variety in sudoku and logic puzzle grids that you could hope to throw a forest worth of sticks at. (Maybe that should be pencils?).  I encourage my dearest readers to follow those links, scroll down to view the instruction booklets, and prepare yourselves.

I have been doing these things since 2007, so I reckon I qualify as a seasoned pro at these things by now; but I doubt you will be that much more bewildered by it all than I am. I suppose I’ve done just enough reading to at least understand all the rules now, but there will be more than a few types that I will encounter for the first time when it really matters, in the competition itself. 

I might save more on the puzzles themselves for tomorrow. It’s getting late and there’s a long week ahead. I’m glad to be back at championships for the first time since 2019, to seeing old friends once again, and also to see how well the competitive juices get going again. My thanks also to the organisers for all they have already done in preparation - I was there in 2014 and once you’ve been through that, you certainly have my solidarity!

pzprPT Masyu experiment

I thought I'd try the same thing as the previous post using the pzprRT interface - this time with Masyu.  

UPDATE: I managed to put out 15 puzzles, which seems absolutely insane to me.  I had speculated that the interface might be a bit more fiddly with Masyu, because you can't just type in numbers - however what won through is the fact that you need far fewer clues to get a valid Masyu puzzle.  So there we go, churn out a puzzle in an average of 2 minutes.  Make of that what you will!

Puzzle 1: 21:32 - https://puzz.link/p?mashu/10/10/16020200033ii000903009222003030160

Solved in 0'50.  A fairly tricky puzzle in the end, although enabled with a repetition of my favourite diagonal pairs in the corner.

Puzzle 2: 21:34 - https://puzz.link/p?mashu/10/10/0000o10021i30010900i64020000360i00

Solved in 0'44.  Mostly smooth, although a couple of tricky deductions.  My initial impressions are this has been a bit more successful than the Slitherlink experiment to come up with puzzles that don't feel too artificial.

Puzzle 3: 21:36 - https://puzz.link/p?mashu/10/10/090109i61033300i900360920000961200

Solved in 1'41.  This is the first one I feel like I missed something - maybe too early to say if that points at a computer generated hallmark, although I didn't really like this as much.

Puzzle 4: 21:38 - https://puzz.link/p?mashu/10/10/10200b03i3010122033006000b03i130i0

Solved in 0'33.  The theme suffered in order to get something unique out, but this was a lovely smooth puzzle to solve.  I might try and rescue this at a later date!

Puzzle 5: 21:40 - https://puzz.link/p?mashu/10/10/09i21000023j0i000ca0009219j0000930

Solved in 1'09.  Solved nicely enough, but with a couple of moments to sit and think.  But these aren't feeling so artificial to me.  I wonder if that's because I'm a reasonably proficient Masyu solver and just get these things quicker than I do with Slitherlink?  Or indeed if there's an upper limit as to how hard you can make Masyu?

Puzzle 6: 21:42 - https://puzz.link/p?mashu/10/10/209000i80030060j000169200409000i30

Solved in 0'26.  Finally got an anti-symmetric one going, and it's just as good as any other in this style that I've ever written.  Interesting!

Puzzle 7: 21:44 - https://puzz.link/p?mashu/10/10/00o0c02000i13i600010b60900302i1900

Solved in 0'27.  On a roll with anti-symmetry.  This one has a really nice design actually - maybe it compares favourably to most of the others in this style I've ever written.  Hmmm!

Puzzle 8: 21:46 - https://puzz.link/p?mashu/10/10/00020910060909i00a2021100200i06090

Solved in 0'49.  I'm beginning to enjoy these!  This one had a couple of my favourite patterns to get things going.

Puzzle 9: 21:48 - https://puzz.link/p?mashu/10/10/30i060200601002693300i391000136000

Solved in 0'36.  Fine again!  A perfectly reasonable puzzle with a don't close the loop early theme.

Puzzle 10: 21:50 - https://puzz.link/p?mashu/10/10/20130300i0309960j0302060100i000990

Solved in 0'35.  Felt like a perfectly good themed puzzle that solved very smoothly to me.

Puzzle 11: 21:52 - https://puzz.link/p?mashu/10/10/0910910a39330c9c910a33a03113310990

Solved in 1'24.  Admittedly I guessed here - I wasn't expecting a puzzle with a random selection of white pearls to give anything other than something that needed guesswork.

Puzzle 12: 21:53 - https://puzz.link/p?mashu/10/10/600060i020i00000606260000620060i00

Solved in 0'30.  I guess all-black pearl puzzles are always going to be less interesting.

Puzzle 13: 21:56 - https://puzz.link/p?mashu/10/10/1930020a30i009077700i03916060010o0

Solved in 0'52.  This attempt at anti-symmetry didn't quite work out, but a perfectly decent puzzle!

Puzzle 14: 21:58 - https://puzz.link/p?mashu/10/10/0062014000042160i0109000o199200000

Solved in 0'37.  Another nice solve!

Puzzle 15: 22:00 - https://puzz.link/p?mashu/10/10/020100226i0030bi00ci2000a330060300

Solved in 0'36 - more antisymmetry and solved well enough.

pzprRT slitherlink experiment

Perhaps I'll reflect more on this after I finish the experiment - but for the time being I'm going to live-blog a slitherlink puzzle setting process which relies entirely on the hugely impressive pzprRT project.  Let's see how many puzzles I can publish in the next 30 minutes...

UPDATE: The answer is 9 puzzles, which feels like a lot for 30 minutes worth of work.  I have now gone through and solved them all - they are unique and cover a surprising range of difficulty levels.  Some of them are more fun to solve than others!

Here are the puzzles:

Puzzle 1: 15:03 - https://puzz.link/p?slither/10/10/332b01co63cg635bkcg7251837bgck735cg25do32a321b

Solved in 1'02.  The solve was a bit disjointed solving symmetric parts of the grid, but after that it was surprisingly smooth.  Not the ugliest looking puzzle in the world either.

Puzzle 2: 15:06 - https://puzz.link/p?slither/10/10/1b0a122c2c1cdhbicdg06ch230bh81dgddidhb2c3b222c3b3d

Solved in 1'59.  A smooth enough start to the puzzle, it got a bit fiddly at the end.  Some interesting topological deductions in play here but it did feel somehow artificial.

Puzzle 3: 15:09 - https://puzz.link/p?slither/10/10/gdch1ckdg111116aahd7706dh8286cchd511111bgdk1dhbb

Solved in 4'29.  I didn't want to have to guess to solve any of these puzzles, but I ended up doing so here.  There's probably a clever topological argument at play here, but this one definitely feels the most computer generated puzzle so far.

Puzzle 4: 15:13 - https://puzz.link/p?slither/10/10/2b51bh2bh11bg26agbh2bc03b212bhac2bhcg52bg33dh2bh38d2b

Solved in 3'13.  Again needed to guess to finish things off at the end, so pretty hard.  You can kind of see how I tried to build up a theme, and then compromised it quickly in order to get out the unique solution.  Not amazing either.

Puzzle 5: 15:17 - https://puzz.link/p?slither/10/10/b3321ao836dbg187126dgabhbdg812672dgb508ao3221cb

Solved in 1'54.  This one I remember trying to set by including a few patterns of clues I'm familiar with.  It kind of works, but not entirely successfully.  Definitely better than the previous two, but still with an undeniable artificial feeling to it.

Puzzle 6: 15:21 - https://puzz.link/p?slither/10/10/g20271bgdgbg7202c75ci5c7c727a8c7ci75c2027cgagbg16202c

Solved in 1'36.  This one is largely easy and with a smooth solve, except for a fiddly end which kind of ruins things a bit.  Again you can see how the initial visual theme got watered down a bit.  I suspect it wouldn't take that much work on this to keep the theme stronger and have a more consistent solve.

Puzzle 7: 15:23 - https://puzz.link/p?slither/10/10/3dj3d1bbi16516aj16751bl16571bj51651bid1b0cj3d

Solved in 1'20.  Basically a taburega puzzle for those familiar with the reference.  Solves smoothly and with a couple of interesting moments, but always with the sense that the thing is one big gimmick.

Puzzle 8: 15:27 - https://puzz.link/p?slither/10/10/gag73bg27bg3627012chdg2c327dg0bg832c2cgch2238270dg62cg15bgb

Solved in 2'16.  This one felt very computer generated.

Puzzle 9: 15:30 - https://puzz.link/p?slither/10/10/jb580d8dpa3580dbblbb0880dap8a355adh

Solved in 0'29.  Nice to have an easy one, although that was always going to be the case using patterns like this.  I suppose if I'm honest I'd have to say this one is fairly taburega-like as well.