I Might Be Wrong

And so as one mind-numbingly large mass sweeps out the last remnants of the approximately planar elliptically shaped space in the heavens above, with the other even more mind-numbingly massive – er – mass squiggling about somewhere in the middle, the year fades away with a festivity induced stupor; a stupor one might add that has consequences that aspire to be swept away as once more the point of something resembling periodicity is reached. All that might tell you that for the next coming weeks, Friday Puzzles is going to be on hold.

Although, I might be wrong. Well, not about Friday Puzzles being on hold, because it is. The subtle implication in using the words “on hold” however suggests that it might be back in the new year, but at this point I’m not sure that it will – or at least that it’ll be back in a hurry.

Now this is not because I’ve suddenly become massively disillusioned with puzzles, or even writing them. That said, I can’t claim to be the most varied, nor prolific, nor even author of the highest quality puzzles out there – not be a long shot on all three counts – but they are pretty decent and I’m sure people enjoy them. Indeed, according to Google analytics which I set up at the end of September, I have had 854 visits (albeit a few of those will have been me) from places that range as far as Los Angeles, Lima, New York, Vancouver, Rio de Janeiro, Tokyo, London, Sofia, Berlin, Shanghai, Melbourne, Delhi – and – Kenilworth (it must be said at this point that I’m still a little befuddled by being referred to by Google via the search terms “girl from glamorgan barrel organ”). There is then, some worth to what I have been doing over the past year.

No, the reason for the pause is just the need for a break. Burning yourself out, and especially burning yourself out whilst chasing arbitrarily self-imposed deadlines, doesn’t make much sense to me. Not that there is much concrete evidence of this immediately apparent to my own eyes, it’s more just a feeling I’ve got of impending staleness. How terrifying!

Despite the self-indulgent nature then, of my series, I am in danger of making this post a little too self-indulgent for its own good. Puzzles will appear on this blog in the future, and I hope that they do so in the Friday Puzzles format – but perhaps not for a while, and perhaps not before I try my hand at a more traditional use for a blog (did I say I STILL hate that ugly ugly word) – that of writing. Although, to end on a suitably sardonic note, many blogs out there on the interweb wouldn’t know writing if it came up to them, engaged them in a duel and then lopped off their heads.

Adios, a merry Christmas to you all, and a happy new year!

Friday Puzzles #28

Another sudoku puzzle this week – I’m not sure why I’ve done two in a row as sudoku tend to be harder work to write than other puzzles. Or at least that’s what I find anyway. This ought not to be as tricky as last week, but I think it’s a pleasant enough solve.

    #033 Sudoku – rated medium

All puzzles © Tom Collyer 2009

Friday Puzzles #27

Apologies for the delay, I’m sure you all know what things are like as Christmas approaches.

This week, I’ve decided to write a sudoku. After much experimentation with a certain pattern, I’ve grudgingly had to modify things a little in order to avoid either an impossibly (well not quite impossible, by definition, but you know what I mean) difficult puzzle, or a puzzle with multiple solutions. Still, after a quick check with scanraid (which actually appears to have renamed itself “SudokuWiki” which IMO is more than a little pretentious and misleading in its current form) to get an indication of the difficulty, it would appear to be on par with a Times fiendish puzzle and so I get the satisfaction of writing a puzzle which ought not be solvable in quite so much of a hurry as my previous efforts.

Another point of discussion is that as sudoku puzzles increase in difficulty, the more guessing strategies become useful if you want to go for the quickest times. This is where hand-made puzzles can come in – the cunning trick to crack the puzzle ought to be more obvious to the solver than a standard puzzle out of the generator. This is purely because the human eye is better equipped to pick up subtle clues as suggested by the aesthetics of the puzzle because said aesthetics are a big deal for the author of sudoku puzzles by hand. I’ve left that statement intentionally a little vague, because I hope dearest reader, that you’ll see exactly what I mean whilst solving. Enjoy!

    #032 Sudoku – rated hard

All puzzles © Tom Collyer 2009

Friday Puzzles #26

Today I’m a little tired, having stayed up far too late last night discussing the merits of what a championship should and shouldn’t be with Thomas Snyder. The discussion became almost tediously technical – e.g. if a championship’s “goal” is to find the “best participant”, then we’d better have a sound definition of what “best” really is, before attempting any sort of statistical analysis of whether a particular format really does find the “best participant”. I claim that no championship can reasonably hope to have that “goal”.

Anyhow I don’t wish to carry on that discussion here, I merely want to excuse my laziness: being tired means that I’ve had to take a little inspiration again, rather than come up with anything properly original. Any puzzle lover should be made aware of MellowMelon’s (aka Palmer Mebane) blog – an incredible site where he puts out some high quality logic puzzles on a daily basis. I can’t claim to have had a go at all of them, since there are only so many hours in a day but I have to say I’m hugely impressed.

One such gem is this nurikabe puzzle: http://mellowmelon.wordpress.com/2009/11/22/puzzle-107/. I’ve tried to put my own (incomplete) twist on his theme today – together with a few ideas previously seen in my own puzzles. Enjoy!

    #031 Nurikabe – rated medium

All puzzles © Tom Collyer 2009

Friday Puzzles #25

Greetings all, and apologies for the delay. I’ve been a little bit distracted in the last few days, but as they say, better late than never.

A plain old Masyu puzzle this week – not quite from the juno textbook but hopefully still a nice enough solve:

Edit: I offer my apologies to anyone who had a go at early versions of this puzzle and were frustrated by the multiple solutions that could have been arrived at, and my thanks to mathgrant whose helpful comments helped me to fix it!

    #030 Masyu – rated medium

All puzzles © Tom Collyer 2009

Friday Puzzles #24

In the last couple of days, I’ve engaged in a discussion on Thomas Snyder’s blog about the subtleties, nuances and differences between computer-generated sudoku puzzles, and human created puzzles; in particular if there is a line to be drawn, and just how blurred it might be. If you are interested in that sort of thing, some fascinating things are discussed.

Inevitably, I’ve taken a bit of inspiration from that and I’ve made a sudoku puzzle for this week, all by myself! I’ve used a slightly infamous pattern – which if a computer generator was left to its own devices to find would probably give you something turned up to 11 (again) – but perhaps said computer generator could be programmed to a certain set of rules, and perhaps it could put out a puzzle with a similar difficulty level without taking an hour and a half to do so.

Either way, I’d like to think that you, dearest reader and most loyal of solvers, might feel something of a human touch in this puzzle. Enjoy.

    #029 Sudoku – rated easy

All puzzles © Tom Collyer 2009

Friday Puzzles #23

Another nurikabe puzzle this week. This one started as a 10×10 puzzle that I thought I’d turn the dial up on slightly. Although perhaps to some people’s disappointment I didn’t quite get as far as 11. Alas. Anyway, it’s a little bit silly – but the whole numberlink/nurikabe logic overlap in the Puzzling Plane still interests me, and there is probably a little more to play with yet. Expect a similar puzzle in the next coming weeks.

    #028 Nurikabe – rated hard

All puzzles © Tom Collyer 2009

Friday Puzzles #22

After a little delay, here’s a nurikabe puzzle. I’m increasingly realising that the nurikabe I write have a different feel from a typical nikoli puzzle – but I don’t like to think of that as necessarily being a disadvantage. Another thing that gets raised in my more neurotic and existential crises about the purpose of this series is that I don’t seem to have many (any? – I can’t remember) hard-rated puzzles. Luckily my conscience is soothed with a nice healthy dose of logic with the realisation that the size of the grids I’m using is a bit of a limiting factor on all of this.

And if you believe all that, you’ll believe anything I write in these blurbs. Honest.

    #027 Nurikabe – rated medium

All puzzles © Tom Collyer 2009

Friday Puzzles #21

So perhaps things have been getting a little too mathsy; and certainly I could do with a sudoku break. So, here are a couple of easy Heyawake puzzles, themed with a small number of numbered rooms. Obviously when you focus on just one of the rules of a puzzle, then you lose some of the richness and variety, and this is the case with these two puzzles. As such they are both pretty easy. Still, I hope they still prove to have at least some fun factor coming from their novelty value. 

    #025 Heyawake – rated easy

    #026 Heyawake – rated easy

I am wondering whether it is possible to do a Heyawake puzzle with no numbered rooms at all – at this stage I’m sort of conjecturing that with enough fiddling about with thin rooms in the corners it ought to be doable…whether that translates into any sort of a fun solve we shall have to see.

All puzzles © Tom Collyer 2009

Friday Puzzles #20

Carrying on from last week, here’s another topologically themed sudoku. This week, it’s the turn of the projective plane. You’ll also have noticed that this week, in a noble and glorious gesture to save the planet, I have removed the colouring of the 9-cell marked regions. Indeed, dear reader, I have potentially saved some of your precious, precious, colour printer ink.

Now, this will make things difficult for those who can’t visualise the surface via the given identification space – and so the puzzle isn’t as hard as it might have been. I might revisit this design in coming weeks to really exploit some of the beautiful logic induced by this particular grid structure.

    #024 Real Projective Plane Sudoku – rated medium

All puzzles © Tom Collyer 2009.

Friday Puzzles #19

The eagle eyed amongst you might have noticed I deleted yesterday’s entry and replaced it with this.

Less waffle, more puzzles to actually do! The idea this week is you have a standard sudoku puzzle to do – and rather than using the toroidal identifications, instead you are using those of the Klein bottle. Rather than try and laboriously try and rigorously explain the rules with respect to quotient spaces, topology, covering spaces, orientability and lots of other maths – what I’ve done instead is labelled the grid and coloured everything in so the rules are all completely obvious.

Who[*] says the internet is shortening attention spans and generally making everyone more stupid anyway?

#023 Klein-bottle Sudoku – rated medium

All puzzles © Tom Collyer 2009

[*] Ah wait, that’d be me. Expect less mercy next week.

Friday Puzzles #18

Every so often, I suddenly stop, and think about the meanings of the words that people are using. A favourite example of mine is the word “awesome”. This is an adjective which you might apply to something that inspires awe in you. The prospect of seeing a mate down the pub isn’t exactly the sort of thing to stop you in tracks and draw your jaw irresistibly down to the floor as the sheer awe of the situation renders any other possible reaction void – and yet it’s a common enough to hear the word used in such a context. I blame Bill & Ted.

Anyhow, another such word is “inspirational”. This is commonly misused, when the careless student of hyperbole wanted the word “fine”, maybe “splendid” (though certainly not “nice”) or perhaps even they might stretch to “excellent” or “wonderful”. Well perhaps not wonderful if the thing in question wasn’t in fact quite full of wonder, but at any rate any other synonym of the word “good” would have done.

However, this week on nikoli.com, an inspirational 36×20 Masyu puzzle authored by a character with the pseudonym juno was posted. I’m sure you’d like nothing back to ram the previous two paragraphs of pedantry right down my throat, but, alas instead I shall provide you with a 10×10 puzzle that was 100% inspired by juno’s masterpiece. Enjoy!

    #022 Masyu – rated medium

All puzzles © Tom Collyer 2009.

Incidentally, I am not going to post juno’s puzzle. You’ll have to suscribe to nikoli.com to have that particular enjoyment, as well as plenty of others.

Nice Dream

So.

If I start by calling myself a two-time national champion , you have fair warning straight away to go and get things done. Or something else instead of reading this. This is a trademark championship review.

The Saturday started by getting up at a reasonable hour – 7.30am – having my three Weetabix and a nice shower. Coventry is a mere hour away on trains that run frequently to Euston, which is itself within walking distance of the University of London’s Institute of Education. Leaving the house at half 8 was plenty comfortable to get to the competition venue for registration at 10. Whilst at the station, I noticed the train was calling at Milton Keynes which was perfect opportunity to meet up with a friend of mine, Andy, who had qualified for his first competition. I tried my hand at the hard sudoku in the Virgin magazine. I struggled, because it really was hard. Still – it was a slightly more riveting experience than Andy’s itouch.

At the venue, the two of us signed in. To Andy’s bemusement, they were handing out free copies of The Times (waste of £1.50); and to mine there was free refreshments including water (waste of about £1.80). (Although it was decent sized 750ml bottle capable of refills). We sat up against the wall, soaking up the incredible nervous atmosphere. Thankfully this was soon broken as George Danker – a by now championship veteran – appeared together with his loud purple shirt and parents, who, beyond providing moral support, also supplied essential transportation.

The Times journalist rather quickly made a beeline towards us. Whether she already knew of mine and George’s pedigree – or whether we simply appeared to be the only people there who didn’t appear to be frightened rabbits in the headlights, I’m not entirely sure. However, she seemed to be a good sport, and explaining quite how these championships work to yet another journalist was quite relaxing before the actual event started. And in fairness to Mary, she seemed like a good sport.

The first round started with me and Andy being a little late into the hall and having to pick out our seats – resulting in me being a little closer to my perceived main rivals George and last year’s champion Nina Pell than I would have ideally preferred. I also spun right round in a vain effort to try and spot Simon Anthony – who previously authored definitive championship blogs – but instead I could only see his crossword-ing chum Mark Goodliffe. Mark was the runner up when I previously won in 2007, and is currently the national crossword champion. This ought to give a good indication as to just how good he is. One day I hope to finish off a Times cryptic. One day.

Err right, I was talking sudoku wasn’t I? The first four puzzles by my standards started in a sluggish gear, plagued by some unnecessary and really quite half-baked bifurcation efforts to try and speed things along. By the time I’d seen Mark finish – in close to 17 minutes – I needed a mental kick up the backside. I saw the easy steps of logic needed to finish up, and was done in 22 minutes. This was 7th place according to Mark, who had been keeping track of finishers. It turned out that he was only 2nd this right. Andy had messed up a puzzle three times, but eventually had all four done and finished in just under 50 minutes.

There was a little break before the second round began. I started this quick. Really quick. Too quick – I had to restart the first puzzle. Fortunately, the rest of the puzzles solved rapidly and smoothly, and I had finished off before 19 minutes were up. Unfortunately, lots of other people had found the round equally as smooth and rapid to solve, and again I was only 7th. However this doesn’t tell the whole story: at this stage I was absolutely petrified that I had made a mistake, and whilst the lady behind me was convinced I’d be fine, I most definitely was not. And even if I was through, it wasn’t exactly in a convincing fashion. A potential final would require a higher gear.

After a small delay after the second round had concluded, the top 8 were announced. I was rather relieved to be standing up in the (unsurprisingly really) 7th spot. Of the eight, there were four I was familiar with: myself, George, Nina and Mark; the other four included the amusingly named Stephen Gerrard, Jason Shannon, Thomas Drake and Abigail Vallis. As things were to transpire, the latter two were both 18 years old. Narrowly missing out on the final in 9th position was a 15 year old girl called XXX – who was named young champion. Interestingly, of the eight finalists only two were women. I have long held the theory that the so-called battle of the sexes is a knowingly playful myth, only perpetuated to appeal to the housewife market that I imagine Sudoku sells best amongst. In terms of UK champions, Nina is doing very well (2005 and 2008) – and Rachel Roth in 2006 performed the minor miracle of beating David McNeill in competition. You might argue that in being the sole representative for the uglier sex that I am the outlier – but I will point you to the demographics of most championships across the globe, and their winners.

There was a break of about an hour before the grand final – allowing the organisers to compile a finishing list for everyone ranked 9th and below. I talked a little more with George and parents – an interesting episode which featured me misdirecting some poor stranger looking for the right lecture hall twice – and also briefly with Mary again where I suggested the preliminary order of the top 8 was unlikely to be the same as the final standings. I had meant to try and catch a word with Nina, but again I couldn’t see her. Instead, me and Andy went upstairs for a breath of fresh air and walked around Russell Square. This walk almost entirely consisted of Andy telling me that the odds of me being the quickest one from eight were rather slim when it appeared the standard appeared to be quite even. I was holding onto the thought that the puzzles in the final would be harder and thus more favourable to me: I have a knack of seeing where a puzzle-cracking bit of logic ought to be when it is crucial to the solving chain; whereas sometimes if there are several solving chains then my radar goes a little awry. I was banking on the others being lightning quick on “easier” fiendish puzzles, and slowing down significantly when the difficulty was notched up slightly – as had happened in 2008.

The grand final was to be held in the same backroom that I had won in 2007, which felt like a good omen. A better omen was handed to me when the top preliminary ranked finish was allocated first choice of seating in the two rows of four formation that the final would take place under, 2nd preliminary placed got 2nd choice etc. People were filling up the edges and the back row first, which I could only read as a sign of tension and nervousness. I had a choice of two seats being 7th pick, and immediately went for the middle seat in the front row. Everything was calm – until we were all off. I went straight at the first puzzle, hit a sticking point, and so decided to go onto the fourth puzzle. I saw something rather devious quite quickly which got it done, confirming to me that the puzzles were certainly on the hard end of fiendish – if not super-fiendish. With that mental crutch safely in place, I cracked the second and third puzzles without a hitch, feeling my heart rate begin to accelerate as that wonderful moment of realisation hit me that: that I was in with a real chance of winning this.

I had no idea how everyone else was getting on of course, but sometimes you simply get into “the zone”, and I can only assume your subconscious picks up each and every little detail from your surroundings because I just knew. Some of the other seven were given a false sign as to how I was getting on, when about 10 minutes in, I moved my arm swiftly forward to grab my drink, took a slurp and put the bottle back down again in one fluid motion. Andy told me later that some of the others had reacted in such a way that indicated they had thought for a split second that I was going to raise my number.

Having completed three puzzles, with the last one already being half filled in, the adrenaline really started to kick in. I was tempted to bifurcate in an effort simply to get the damn puzzle solved and wrap up the championship; I started to do so but realised quickly that I was so out of practice at doing it efficiently that it was simply a non-starter. This was a wise decision, as I was soon to find the bit that cracked the puzzle. Each of the last few digits I pencilled in seemed to coincide with my pulse, and I made a conscious effort to mentally note the numbers as I wrote them in, to prevent another heartbreakingly infamous transposition. When the last one had gone in, I rather triumphantly thrust forth my number into the hair two-handed, done in slightly under 17 minutes. That faded as I waited for everyone else to finish, and the whole “what if I’ve made a mistake”. This was to last about half an hour until the last of the eight finished, followed by a fairly inept and painstaking reverse reading out of the results – whereby one of us who had finished in 17 minutes had unfortunately made a mistake – which I could have sworn was me but eventually transpired not to be me. At which point I finally knew I’d won.

That was not quite it, the ensuing photos, another brief interview with Mary and a presentation ceremony took a little longer. It was good to see my old trophy back again, and even better to be handed a giant novelty cheque for £1,000. Not accepted at several bars in Central London, apparently. Although a signed freebee Sudoku book was received by a couple on the train back home.

As a postscript, I’m going to stick up the final 4 puzzles. They were published in The Times on 28th September 2009 but haven’t appeared on The Times’ website yet. I don’t have explicit permission to post them, but on the other hand the only reason I’m sticking these up is entirely for demonstrative purposes: there is no income from this website.

    Grand Final Puzzle #1

    Grand Final Puzzle #2

    Grand Final Puzzle #3

    Grand Final Puzzle #4

Friday Puzzles #16

You may have heard I became a two-time national champion last weekend. Haha – that’s all well and good because though I’m fairly proficient at solving reasonably difficult sudoku, I’m a bit crap at writing them. Nevertheless, there was no way that I wasn’t going to write a sudoku this week, and here it is.

I expect some rapid times – I haven’t gone at it myself but I suspect that quickest possible is closer to 1 minute than it is to 2.

And with regards to the championships? Expect a nice long and boring write-up of that soon! :)

    #021 Sudoku – rated easy

All puzzles © Tom Collyer 2009

I Will - a.k.a. Friday Puzzles #15

This week’s entry in my Friday Puzzles series gets its own proper Radiohead-song-title because I’ve managed to go off on one and explored a few deeper avenues than I would have normally done.

Last week’s introduction to the Heyawake puzzle I have decided was a bit hard as an introduction to the puzzle – although I’m now confident it wasn’t totally unfair having had this feedback from one of the best nikoli.com solvers out there:

"I liked it! The start was simple enough, and then you made some medium-level deductions to get some big sets of blocks, etc. I’d say the grand finale (I felt pretty sure there were two solutions or more…no, I was wrong) isn’t as bad as you claim. It probably shouldn’t be someone’s first Heyawake, but it’s not the pinnacle of difficulty. It’s a harder medium, how’s that for a/n non-/answer?"

On the other hand, I’ve been having a little think about the nature of difficulty and the nature elegance within a puzzle. I think it’s fair to say that by no means are the two are correlated – see this entry for two examples of sudoku too hard to be elegant – well elegant for the pen and pencil solver anyway. To labour the point a little bit more, here is an example of a puzzle which is INSANELY difficult. If you solve it, the only logical deduction is that you used a computer:

I found that puzzle after routing around a forum discussion of the hardest sudoku puzzles, it has been given the slightly affectionate nickname “Platinum Blonde”. These people have gone way beyond the solving capabilities of any human solver. So whilst I may have claimed previously that the 2009 Zilina world record puzzle was as hard as it gets and that it’d be the puzzle Beelzebub himself would set you to save your soul – actually the behemoths these people whip up for each other you are doing extremely well to solve even if you use lots of trial and error. I recommend not even starting to attempt.

Now, on the other hand, some easy puzzles can be extremely elegant. Not necessarily in the techniques required to solve them in isolation, but how the techniques come together to form a complete and satisfying solve. What this could mean for example, is a puzzle that has a definite starting point, which leads directly to another deduction and so on – inducing a “continuous flow” to the solving experience. It may be a repetition of a particular solving technique, or it may be a particular visual pattern that emerges as you solve the puzzle. I guess much like any art form, there isn’t really a satisfying way to define what makes a beautiful puzzle – but even a complete novice can spot it and enjoy it when they see it.

Anyhow, that’s an awful lot to aspire to. I’m not quite sure how much of that I’ve managed to achieve with this Heyawake (if any at all), but I’m running out of time to fiddle with it today…

    #020 Heyawake – rated easy

All puzzles © Tom Collyer 2009

Friday Puzzles #14

So this week’s (last week’s?) puzzle was slightly delayed as I was concentrating on the nikoli sudoku time trial. My laptop was to have other ideas: deciding to delete/corrupt/mutilate/whatever a crucial windows system folder – and so I had to rush to a computer room to take part. Being all of a fluster, and starting a full minute late I managed a meagre 6th. Having gone back later, I improved upon my time by nearly two minutes. C’est la vie.

The upshot of all that is that I wanted to write my own fairly challenging sudoku – but I find writing Sudoku puzzles (or at least good ones) to be a lot more challenging than other nikoli puzzle types. So, cutting my losses for now, I’ve instead tried my hand at Heyawake. You can find the rules to the puzzle here.

I probably ought to have introduced the puzzle to my blog with a nice gentle introduction – but instead I’ve gone with a sink-or-swim puzzle where you’ll have to do a bit of thinking about the rules and their implications.

    #019 Heyawake – rated medium

All puzzles © Tom Collyer 2009

Friday Puzzles #13

For a lovely sunny Friday afternoon, what could be nicer than to solve a couple of gentle Masyu puzzles? Well that sounded just a little bit too soporific for me, so I decided to spice things up with a little segregation. I give you all-white and all-black Masyu.

Note that you only really get great Masyu puzzles when whites and black are working in tandem – these I guess are more “concept” puzzles. Whatever that means. Still, if Tony’s reading I’m sure he’ll appreciate how wonderful and orderly these puzzles are.

    #017 Masyu – rated easy

    #018 Masyu – rated easy

 All puzzles © Tom Collyer 2009

P.S. You may be thinking that I’m a bit a bit of a casual racist – but if you wish to complain, I shall roll up my copy of the Daily Mail and beat you to death with it. So there.

Friday Puzzles #12

So I’ve recently managed to get a reader hooked to the Nurikabe puzzle, which I am feeling quite pleased about because it is a rather nice puzzle. Thus far I have only really produced three of the Nikoli puzzle types (together with some variations upon their themes) – and I have been in two minds as to whether to branch out. This week the decision was placed into my own hands, as I got a bit lazy and so had to stick with something familiar.

However, having seen a link to a contest to publish a completely original puzzle, I have been having a think. In the works I’ve got something that manages to combine elements of Slitherlink with that of Nurikabe. More to come on that in the next few weeks.

Back to the here and now though, here’s a Masyu puzzle. I unsuccessfully tried to force in some global thinking into this puzzle; trying to nail down uniqueness invariably seemed to simplify things a little bit too much. Still, I’ve thrown in a little tributary “best of” Masyu tricks that I’ve seen on nikoli.com fairly recently. If you’ve seen these before, it’ll be possible to whizz through this in under a minute – 45s on paper from me to beat – if not there’ll be a couple of things you’ll need to think about.

    #016 Masyu – rated medium

All puzzles © Tom Collyer 2009

Friday Puzzles #11

OK, so this week I’ve taken a bit of inspiration from Thomas Snyder and his spin on a small sized Nurikabe puzzle. I think this is only fair, as he seems to have taken inspiration from my Friday puzzles idea; and although the weekly numbering appears to be concurrent, bear in mind I had a gap for a few weeks in June.

Anyhow, instead of localised island and sea grabbing – the mainstay of any Nurikabe solver’s arsenal – he’s created a puzzle which requires a little more global thinking. And he’s made it pretty damn hard in doing so. Which got me thinking about what I could come up with. Now, my effort is arguably a little less polished – but there is a rather delicious twist to this puzzle; a twist that pretty much cracks the puzzle in one (rather than having to slog through this by brute force). This is most definitely a toughie – enjoy!

    #015 Nurikabe – rated hard

All puzzles © Tom Collyer 2009

Friday Puzzles #10

This week comes with a bit of a special theme. The number 10. It’s also very special in that I have managed to get this out and published on a Friday. Wow!

As regular readers may or may not know, last April I participated in the 4th World Sudoku Championships, hosted in a dusty provincial Slovakian town called Zilina. Much was made of the (lack of) quality of many of the puzzles – but one of the most enjoyable puzzles was a variant that appeared in the semi final:

    Puzzle M3 – World Sudoku Championship, Zilina 2009

The idea was simple – take a classic sudoku, and mark exactly where an adjacent pair of digits summed to 10. So if a 3 and a 7 were next to each other, a cage was drawn round and marked 10. The twist with this is the contrapositive inference – that is if no cage exists round a pair of adjacent cells, then the numbers inside cannot sum to 10! The puzzle itself had only one such pair of numbers marked – which made me wonder if actually you could go one better and perfect the puzzle.

Well, it turns out you can. After a lot of painstaking work to first even find a valid solution grid, I then wrestled with the task of making a decent puzzle – with my given visual theme. The result isn’t particularly challenging – though not totally trivial.

I do also have a couple of very hard puzzles too. They turned out to be hard almost by chance – they certainly aren’t a particularly pleasant solve in my opinion and so I haven’t bothered publishing them. Anyhow – without further ado, here’s the preamble: place the digits 1-9 in each row column and marked 3×3 box. Digits in adjacent cells may not sum to 10.

    #014 No Tens Sudoku – rated easy

All puzzles © Tom Collyer 2009. Well, obviously excepting the world championship puzzle above. I have no idea who to credit that to – and whilst used without permission, I’d like to think that demonstrating it would come under fair use. Anyhow, please respect the rights of the author.

Friday Puzzles #9

Here’s a toroidal nurikabe puzzle. Ditto the comment for toroidal masyu – strictly speaking, removing the boundaries of the puzzle actual lifts a restriction rather than imposes one. However, having to change your thinking to deal with identification spaces isn’t the easiest thing in the world to do if you aren’t used to it!

    #013 Toroidal Nurikabe – rated easy

All puzzles © Tom Collyer 2009

Friday Puzzles #8

So it’s perhaps a little odd to have the 8th posting up before I actually finished the 7th one. But that’s the way I roll. Today, continuing on the whole topological theme, I have applied the Toroidal “constraint” to Masyu. That is, lines are allowed to run off the left and come back on the right, and off the top and back on through the bottom. Some might say it’s simply Euclidean space quotiented out by the word ab-1b-1.

Now I say “constraint”, because actually in Masyu having an edge is quite a big thing – so some of the logical deductions you make might seem counter-intuitive.

Bonus points if you can identify the homology class of this loop – using a sensible choice of generators a and b. :)

    #012 Toroidal Masyu – rated medium

All puzzles © Tom Collyer 2009

Friday Puzzles #7

Place holder because I’m late and I’m heading off this weekend and bleh.

Another couple of double-toroidal sudoku coming…

adios!

Friday puzzles #6

Wow – I’m like totally on schedule. And I’m going to introduce double-toroidal sudoku. Basically it’s sudoku, which lives on a double-torus. Now, the inherent geometry on a double-torus is not Euclidean, but hyperbolic. All that means for those I’ve hopefully confused is that you can’t get a rows and columns arrangement placed on it – which is why this looks a little different. The puzzle is “octagonal” in shape – and just as you glue opposite sides of a square to get a torus, you can glue opposite sides of an octagon to get a double-torus.

So here’s what you need to solve it. There are 6 marked regions with which you want to place the numbers 1-8. There are also 8 “bands” – which start from the centre of each edge of the octagon, and work their way to the opposite edge of the octagon through cells which meet at opposite edges. These are 8 cells long, and again you want to place the numbers 1-8 in each. Basically, it’s exactly the same idea as Penrose sudoku

Finally, there are 2 bands around the perimeter of the octagon, each 16 cells long. (Can you see them?) Any consecutive 8 cells in these two bands again contain the digits 1-8. All of these constraints together are actually very strong – so a lot of the clues below are unnecessary. However I made the puzzle easier so that you can figure out some of the nuances of the puzzle’s geometry in time for a monster next week. :)

    #010 Double-Toroidal Sudoku – rated medium

All puzzles © Tom Collyer 2009

Friday puzzles #5

Back after a gap of too long I know, but here are two nurikabe puzzles. If you’ve forgotten the rules, I refer you back here.

    #008 Nurikabe – rated medium

    #009 Nurikabe – rated easy

All puzzles © Tom Collyer 2009

Friday puzzles #4

Following its incredible introduction to the world in the finals of the first sudoku world championships in 2006, the toroidal variant gets the pulse of any enthuasiast racing. My effort is in much the same spirit as that original.

The rules are: Fill in each column, row and each region with the numbers 1-9. Some of the regions run off (for example) the top edge of the grid. They continue up from the bottom edge of the grid. Similarly with the left/right edges. The idea is that if you take a nice square, glue left side to right side, and then the top edge – now a circle – to the bottom edge you get a torus – and hence the adjective toroidal. Although if you too are a dabbler in the dark arts of pedantry, you will have noticed that actually a classic sudoku is also “toroidal”. But arguably not as hard. :)

All that is left to be said is this puzzle deserves a slot by itself. Back to two (or more) next week!

    #007 toroidal sudoku – rated hard

All puzzles © Tom Collyer 2009

P.S. The next 2-3 Friday’s might suffer some delays too. I’d say there is approximately a 1/7 chance of the puzzles being published on a Friday, but I’ll nevertheless try to keep to the deadline!

Friday puzzles #3

Ok, so delayed a little later than Sunday. I’ve been busy.

On the other hand, here’s a sudoku with the givens in the shape of a Yin-Yang. Only I’ve just noticed that’s only true modulo a reflection – and we all know the sorts of trouble that quotienting out by an involution can get us into. So tomorrow I’ll put up a properly shaped puzzle. :)

Enjoy this incredibly easy fodder for now though!

    #005 sudoku – rated easy

EDIT: Here is the new, improved, properly shaped and rather nicely themed version, if I do say so myself. However, the large number of givens really does mean that it is still very easy.

    #006 sudoku – rated easy

All puzzles © Tom Collyer 2009

Friday Puzzles #2

Ok so this is getting a bit late now; on the other hand perhaps it’s not if you live in Hawaii. That’s the way it goes.

This week’s offerings are two Nikoli staples.

Masyu is a loop puzzle, where you try and join a loop in a grid containing white and black circles. The loop must pass through each of the circles; through a white circle the loop must go straight through, but then makes a 90 degree turn in one of the next squares. At a black circle, the loop makes a 90 degree turns, and then extends on in a straight line for at least two squares. See more here.

Nurikabe is an islands puzzle. You are given a grid of squares which must be coloured white or black. Each of the given numbers lies in an island comprised of the relevant number of white squares. Surrounding each island is a sea of black squares, subject to certain restrictions. Firstly the black squares are all connected, and secondly, given any 2×2 block of squares, at least one must be white. See more here.

    #003 Masyu – rated easy

    #004 Nurikabe – rated medium

All puzzles © Tom Collyer 2009

Tom Collyer writes some logic puzzles...

A.K.A. Friday Puzzles #1

Hello all. Recently I have taken up writing logic puzzles as an excellent means of wasting time – but also as a potential future earner. I am now at the stage where I am willing to publish them to the internet in a bid to firstly start a bit of a following, and a bit of feedback – and secondly to start buidling my own personal reputation. The idea is to start publishing a weekly puzzle that I have written myself. This is a learning process for me so the soving difficulty of my puzzles will probably vary wildly, but I’ll try and pigeon-hole them into three categories – easy, medium, and hard.

Anyhow, it ought to be fairly obvious that one of my favourite logic puzzles is sudoku, and so provides as good a place to start. Most sudoku you will solve tend to come from newspapers and books, and almost all of these will have been generated by a computer. The benefits of actually having a person make them I hope will become obvious as you solve these.

Please note that my puzzles are not all going to be sudoku. That’s not even close to what I aim to do. Where I publish a puzzle that is relatively obscure, I will post up the rules and perhaps a couple of examples of how they are applied. However, I’m sure everyone’s perfectly fine with sudoku, so without further ado:

    #001 Sudoku – rated easy

    #002 Sudoku – rated easy

All puzzles © Tom Collyer 2009

WSC Zilina report part 7

This time I had a co-solver, Giulia Franceschini of Italy. Like I say I normally get annoyed with people pointing stuff out to me whilst solving, but a pretty face paired with actually being a pretty handy solver helps a lot. I’m really quite smug to say that our joint efforts had whopped Thomas and Wei-Hwa’s individual efforts (although both had used actual sudoku grids together with the unhelpful third 1-9 constraint). On the other hand, the slow process of drawing out the grids and regions and numbers wasn’t quick enough to trump the new 2009 World Sudoku Champion, Jan Mrozowski of Poland. I will point out that we were equally as handicapped as we were solving literally stood up with the paper held out in front of me.

And that was that, or so we thought. Apparently the Turks had a complaint about some aspect of the final – I didn’t quite understand what the grounds were, but there we go. What now added to the confusion was that the 4d sudoku guys were (apparently – I merely speculate here) not quite impressed by the slightly modified rules by which it was “solved” in the team rounds, and had appeared to spontaneously have organised an extra round whereby the 8 finalists would try and solve the puzzle proper in 15 minutes. This is as ridiculous as it sounds, but at this stage, we weren’t quite sure whether this constituted some sort of extra final play-off, due to the Turks’ complaint not being resolved. More than that, this time they’d actually be up on the stage in view of everyone. Again, no-one had any idea whatsoever what was actually happening. Another notch up on the Snyder scale of ridiculousness no doubt, but by this point Thomas was hammering out his viewpoints onto his livejournal page.

This did, however, give me the chance to get pun of the championship. This is a self-awarded title admittedly, but aside from an award for the most stupid semi-finals preparation it’s the only tangible prize I could take back with me from Zilina. As the bearded brothers in their garish black and orange self-branded polo shirts tried to explain the rules of their puzzle again, they mentioned the key to the puzzle was that there is exactly one blank outer face on the cube. My interpretation – given the confusion – was that there were actually eight blank faces up there on the stage. Well, at least Nick Baxter liked it a lot.

Rather appropriately however, this stupid distraction – it turned out the Turks’ complaint was not upheld and indeed Jan was still World Champion – was overshadowed when at the American’s table, Wei-Hwa had announced he’d finished the puzzle. Given his break to simulsolve the final puzzles, he’d managed it in about three quarters of an hour, which is probably as fast as anyone is EVER likely to solve the puzzle from scratch. Suddenly attention diverted from the stage to Wei-Hwa, and even the bearded brothers abandoned the floundering finalists to congratulate them. The Japanese finalist, Ko Okamato summed up the mood best as he sat up on stage, slumped in his chair, ignoring the puzzle and instead sat there sulking. Fair enough to the guy.

Still, I have no hesitancy in saying Wei-Hwa’s is one of the finest minds on this planet – if anyone was going to whop the puzzle it was him. He remarked to me that there was definitely a clear logical process that had guided his solving rather than mere trial and error, and I am quite happy to take the guy at his word. Although the teams were allowed to keep one puzzle each, I have no desire to addict myself to something else. I suggested to Ariane that she might like to give it away with one of her magazines.

And that was that for competitive sudoku. In theory this was now time for a little bit of socialising, but instead, a myriad of entertainers – including a mime artist, a troupe of kids from Slovakia’s got talent, some dancers and what appeared to be didgereedoo players. Some people were still puzzling however, and I drew out both puzzles for David, and watched him solve. Again the huge sizes makes a difference but he completely caned both puzzles up. If he’d have been in the final I’m fairly sure he’d have been the champion – and a well deserved one too! There’s always next year.

Did I mention the dancers by the way? Their first set resembled some Bollywood dancing, possibly because last year’s WSC . I presumed the next set was meant to represent next year’s lot in America – but frankly it was the sort of raunchy debauchery you’d associate with the Moulin Rouge. David, as a very committed married man, did his best to try and avert his gaze. Thomas too seemed more concerned with his livejournal posting on his laptop – but everyone else’s attention was drawn to the stage. Man, it was hot!

The entertainment dragged on, and at some point there was a presentation for the winners – the home crowd was happy as the Slovakians had won the team competition marginally ahead of the Czechs – but it wasn’t terribly exciting as I didn’t really know any of the winners. We grabbed some buffet dinner, and again I applied my Rootes restaurant strategy of taking one plate, and piling it high with as much quantity and variety of food as is physically possible. After dinner, I had an inspiring conversation together with David, Mike and the Americans Nick and Will Shortz. Unofficially speaking, they were looking forward to bettering the efforts of the Slovakians for the championship in Philadelphia next year. Some rather tongue in cheek variants were put forward – David mentioned trying to get the idea of Kerplunk! into sudoku – but I liked the idea of some electronic tetris variant, together with cheesy 80’s music and charming pixelated graphics!

The celebrations had already begun, and we met one of the Germans (Hubert Wagner I believe) who had been sent to the hotel bar to bring more wine for the Germans. They had seemed to have been locked in, so we gallantly offered to help him with his two bottles. Eventually the rest of the Germans came out to get the rest of their drink. More fun was to come as the Slovakians came up, together with some ice cold bottles of slivovica and marhuľovica – being plum and apricot brandies respectively.

The thing here is that with spirits that cold, a small layer of pure alcohol forms on the top of the shot – which I might add are rather larger than shots as we in the UK know them – the layer then pretty much forcing you to down in one. The apricot at 40% was slightly less severe than the plum at 50% ABV – and watching the Irish boys at work was quite a spectacle. Another fantastic quote from them was:

We’re not actually better drinkers than the rest of the world. We’ve simply got a reputation to uphold!

After a couple of downed “shots” they were really struggling. It should come as no surprise however, that the drinks rapidly disappeared – and being a Sunday evening the hotel bars has closed relatively early. Thus we were in the situation at midnight whereby a lot of us wanted to drink more, and some of us who didn’t want to go to bed because they had to start their journeys back at 3am. The only solution was to head out into town.

It had all looked very disappointing as we headed back to the town square, as being midnight on a Sunday everything was shut. And then the Gods smiled upon us – one lady who had just finished closing up her bistro place come and said she could reopen for a large group of well-paying tourists. This is possibly the best thing ever. We drank lots of beer, and were even able to order some pizza. Gradually people did drop off however, and by half 5 in the morning the owners balanced the money/sleep balance into the favour of sleep and kicked us all out. I was left walking back to the hotel with a Times reporter as the sun rose, and as the rest of Zilina appeared to be getting up for the start of a working week. Strange indeed.

And that, I believe is a good place to finish. Well almost. I had to be on a train to Bratislava at half 8 – and only just managed (by 45 seconds!!) to make it. I had slept unti five past eight and had to sprint, bags and all, to the station. My Slovak as I hurried tried to buy tickets was exemplary. The rest of the journey involved lots of sleep, and being poisoned at some dodgy tapas joint in London. But that’s another story.

Thanks for reading!

WSC Zilina report part 6

Lunch at the ex communist stronghold, Hotel Slovakia was an interesting affair. The big plates had gone pretty quickly, so my buffet style lunch was piled up on something taken from near the salads. The only purpose I could see it was fit for was to support a lovely cup of tea but I struggled on. The view from outside the window was of a car park. Not jusst any car park though, a hideously ugly car park. Whilst it is possible to say that most car park architecture could be described as anti-renaissance, this was literally a giant breeze block. It made the old Tricorn centre look a painstakingly hand-sculpted masterpiece. We in Britain do complain an awful a lot (the Tricorn centre looked so terrible, even against the backdrop of Portsmouth, that it was blown up. After several attempts.) but I get the feeling that in Slovakia practicality is king.

The results were put up on the wall. David was in prime self-kicking form, especially as he gave the puzzle he had misread. I had a lot of sympathy with him – given my experiences last September I know how painful messing up qualifiers for a final you would have aced actually is. If he had have been in that final, there is no doubt that Jan Mrozowski would have had to share that favourite tag. There isn’t really too much you can say to someone in that situation, so we left him puzzling for a little while – before finally we had to go fetch him so we could walk back to the more Westernised Holiday Inn.

It was a stunning day for a lovely Sunday afternoon walk, and we were accompanied by the pretty translator girls, who were to act as impromptu tour guides – ours was Monica. Jason in particular had taken a shine to them, and felt a little bit guilty when he heard they were high school age – although David assures us this was known as they introduced to us on the Friday night. Parts of Zilina were also very pretty, and we went in a couple of churches as most other things were closed. There was also a nice square, with lots of promising looking bars as well as a nice fountain. (Kudos here to the organisers for ensuring the only time off to sight-see was when things were shut.) Other parts – such as the huge hole in the ground – and the Tesco superstore weren’t so pretty. Unfortunately, our tour had to be cut short as proceedings. Not before I had attempted to sell Warwick as a great choice of university for our translators; although, alas, their hearts seemed to be set on America.

Back at the hotel, there was just enough time to grab a refreshing lemonade from the bar – especially sweet because the supply of water bottles at the Hotel Slovakia had doubtlessly been redistributed for the greater good and had thus run out very quickly. Interestingly, the final ceremonies were to encompass a team “final” – which rather counter-intuitively involved ALL the teams (not that I should be complaining about a lack of exclusivity) – and the individual final. We headed up into the big room and we were instructed to sit on tables organised again by countries. The tables themselves were laid out for the dinner which was to come later, making the prospects of puzzle solving on them intriguing.

Team “Final”

Ariane, pre-empting another potential water situation had bought some bottles for us at the bar for this final session. She needn’t have bothered as the decadent Holiday Inn had provided about 20 bottles per table. The first puzzle was a monster 16 digit “sudoku cube” presented on a flat piece of paper, with six faces and identifications made by relay tracks to ensure. Topologically speaking, I thought this was pretty impressive! However, once you go beyond 9 numbers in sudoku, speed goes out of the window and 15 minutes wasn’t really enough to make satisfactory progress on the puzzle – despite my rather innovative coordinate system approach which helped to simplify matters for 3 people solving simultaneously.

We were next introduced to the championship’s VIP’s. Originally these were advertised as being Wayne Gould, sudoku’s most successful publicist (you can blame the worldwide craze on him) and Maki Kaji, CEO of Nikoli. Both of these are heavyweight names in the puzzling world and I’d have liked to have had the chance to meet them both. Instead, both had pulled out for personal reasons, and instead we were treated to middle-aged bearded and pony-tailed English blokes. They were championing their puzzle, a so-called 4-D sudoku. I’m not sure how valid that claim was mathematically speaking, although I will concede that solving the puzzle living in a four dimensional world would simplify matters immensely. Anyway, I don’t want to snear too much (now), it is a fun puzzle although perhaps slightly overpriced at £25.

Anyhow, this formed the basis for the last team round – get as many of the 27 complete faces as possible in 15 minutes. We got three, not particularly great – but the maximum anyone got was five, which incidentally was what the UK A team managed. This was the one round where they managed to live up to the their tag as the premier UK team!

After this team competition were over, there was a little more scope for mingling with other countries – an aspect of these championships that was lacking somewhat. We spoke a little more with Jason and I finally got the chance to glimpse him solving kakuro in person. Unfortunately he’d already done all the easy puzzles, and was instead working through a really big and hard puzzle. This became less interesting than it had seemed at first. I also got a chance to have more words with Thomas, and Wei-Hwa. Wei-Hwa was bidding to become only the 4th ever person to actually finish off the “4d” sudoku. The previous record had been in the order of days! Thomas and I were speculating on the format of the final – which hadn’t really been specified – even though (as Nick pointed out) it should have been under WPF rules.

Individual final

And then our worst fears were realised as it became apparent that the finals would be done on the wall, on huge even-larger-than-A1 sized (if such a size of paper indeed exists) grids. Jack was floating around in journalist mode, and got this absolute gem of a quote from Thomas:

The ridiculousness of it has gone up another notch. It is like you’ve had a championship for basketball and then for the final you have a different sized ball, higher hoops and trampolines on your shoes. It’s a crap shoot. Why don’t we just line them up, give them a pack of cards, and let them play poker until they get a winner?

My own observation was perhaps a little more sober in its tone:

The grids in the final were so large that contestants had to retreat a step from them to see the whole puzzle.

The idea of having these super-sized was puzzles was so the audience could see – although quite what was wrong with the system in previous years, where table-top spot cameras were employed to broadcast the finalists solving normal sized puzzes onto a big screen, I’m not entirely sure. Anyhow, the first puzzle – a classic sudoku – was visible for a good couple of minutes before the finalists were let loose. It soon became apparent that this was a fairly easy sudoku (roughly Times difficult standard) as it was fairly easy to mentally place 10-20 digits without too much trouble. I fetched some paper out of my bag copied out the numbers and decided to do a simul-solve. A few people gathered round, including Thomas with his inevitable and incredibly off-putting simul-simul-solve commentary. I jokingly remark to anyone who is interested that the reason I have become a world-class sudoku solver is because I got so pissed off with people telling me “that’s a 5”, or “oooh you’ve missed a really easy one there” whilst solving that the only solution was to see all of these things before they did. However, being quicker than a two-tme world champion is beyond me. For now!

Equally as inevitably, with my rushed scruffy handwriting I had made a mistake due to not recognising a number I’d written in. Instead I looked up to watch how the finalists were getting on – and predictably Jan Mrozowski was leading the field. Wei-Hwa had finished off the puzzle remarkably quickly. It was easy, although had a sticking point later on which fell to a technique called “colouring” – which doesn’t really appear in newspaper puzzles but isn’t too hard to get your head around the logic. I then managed to finish off my bodge job on the first puzzle, before they competitors started the second of the two final puzzles.

Apparently one of the first puzzles had “gone off the wall” (to borrow a headline) and had revealed some sort of diagonal constraint and a coloured region – and clues which pointed towards something that wasn’t quite a sudoku in the sense that there was a well-defined third constraint of 1-9’s, as well as in rows and columns. Or as you might have read in the Times: It’s not a sudoku. It’s a Latin square with certain restrictions. Perhaps I’m revelling a little bit much in my own meagre press coverage here haha – so back to the story – I reached for some paper and began the laborious task of sketching out the grid together with its numerous constraints.

This entry is getting a tad long – so I’m splitting up this split here!

WSC Zilina report part 5

Waking up on the Sunday morning, on approximately 4 hours sleep, I wasn’t feeling too bad – although the lack of hot water in the shower was irksome. At this point my approach to a lack of sleep had become akin to that of running a major economy. When in trouble throw lots of clever devices at the deficit and pay it all back much, much later. Although I’m still tying to work out what’s so clever about Red Bull during the day and drinking by night. I joined the rest of the team for a rushed breakfast. I was sorry to observe the continued lack of marmalade but on the other hand was grateful to get any sort of food. Even more thankfully, the coffee was good enough to knock down in one as we had to rush off sharpish.

The remaining rounds were not going to be in the Holiday Inn, but rather in the Hotel Slovakia. We were to be transferred there by bus – although the American team decided to chance their luck and enjoy a walk in the beautiful morning sunshine. Arriving at the hotel, the impression I got was not so much “hmm, well it’s a bit Eastern Bloc”, but rather “bloody hell, this is the Communist Party’s headquarters”. My sleep deprivation was beginning to kick in and so I wasn’t quite aware of the hubbub beginning to develop as people crowded round the lists of the top 36 performers who had made the semi-finals. It turned out that I was good enough to make them (having finished up 28th), along with David, whose qualification was never in doubt. Although it’s probably fair to say he’d had a bit of a shocking performance overall, he had had a pretty good round A, and again the weightings of things ensured that he had gotten through no problems, in around 18th. Top of the pops? Who else but Thomas Snyder. This was his moral victory. Near the top were other familiar contenders, such as Jakob Ondrousek, Jan Mrozowski, Peter Hudak, Michael Ley, Hideaki Jo and Yuhei Kusui. Missing out were a few surprise names, such as former world champion Jana Tylova, multiple world puzzle champion Wei-Hwa Huang and arguably the best kakuro solver on the planet, none other than Jason Zuffranieri.

I have since noted that without my usual compliment of dickhead errors, I’d have had a score fairly close to David’s. I was pretty happy to be a clear second in the UK team. However, the real mockery of the puzzler media qualification system (of which I’ve had strong words to say before) is that George and Michael were the next best performers. The two sponsored qualifiers were the worst performers on the team – although in fairness to Nina and Mike they were also the ones with the least recent WSC experience, and their journey over could also have had something to do with their performance. Nevertheless, adaptability is something that’ll need to be accounted for next year in Philadelphia. For all-round puzzling greatness I hope David is once again guaranteed a spot, and for outstanding team versatility, I’d like to see Michael go over too.

Anyhow, back to the narrative. The first round of the day was to be a team round:

Round L

This was apparently a strategy round – there were 10 puzzles to complete in two and a half hours but the catch was the team could only have one puzzle face up and available to be worked on at a time. Three people working on one puzzle does sound to be fairly contrived and awkward, but the combination of myself with George and Michael absolutely nailed 9 of the puzzles, getting them out of the way well within the first hour. The trouble was, the last puzzle was a dominos variant that resisted multiple angles of attack and was without any logical entry into the puzzle. We didn’t get it finished despite having lots of time on it. This situation was repeated by most of the other teams – although I suppose more through chance than anything else a couple of teams did manage to get out the dominos puzzle. Analysing this round, I had personally found it nice to be solving puzzles without having to guess – but from a competitive point of view the whole thing was a complete waste of time. For all intents and purposes it placed the UK B team in joint 6th – if you ignore the ridiculous bonus system which I’ll come to shortly.

Round M – Individual semi-finals

The time was now approaching midday and the semi-finals were to kick off shortly. The 36 qualifiers were lined up into four columns which represented four simultaneous heats. The winner from each heat was to go through, and then the next best four taken from any of the heats were to make it through to make up eight grand finalists. The format was 45 minutes to solve four puzzles. These were all pretty tough, and I wasted a good 15-20 minutes on a puzzle that I’d manage to break. In the end I had a bit of nightmare and only got one puzzle out. C’est la vie.

The real scandal here was who had actually been judged to have done best. Although noone had got all four puzzles out, numerous people had managed to get three out. Here, points scoring went out of the window to a certain extent, and the real qualifier was who had handed in early – thus “proving” they had done three puzzles quicker than anyone else.

Frankly, time differentiating should only come into things if all puzzles have been completed. If not, you get a situation when one of the best solvers on the planet nearly (but not quite) gets the fourth puzzle out, and is eliminated by tactical declarations by people who had barely managed to get three puzzles out. Like I said, finishing top of the pile of the individual standings was Thomas’s moral victory – and if he had declared early on completing the third puzzle there is little doubt in my mind he’d have had a third consecutive world title.

David would have had three puzzles out, but misread the rules and had not satisfied the full constraints of the puzzle. He was in a relatively weak heat and so if he had finished this puzzle would probably have made the grand final. Again, c’est la vie.

As it happened, only one of the provisional top eight had actually qualified for the grand final – and thus Jan Mrozowski of Poland was established as runway favourite for the final. And with that it was time to get some lunch.

WSC Zilina report part 4

Again Team UK (and here I make the succinct point that we were most certainly not Team GB when our star solver was Northern Irish) gathered for dinner in the hotel’s restaurant. Now was the time for the promised pork and dumplings – but as it turned out it was a little of a let down as it came served atop of a huge mound of pickled red cabbage. It’s not as if I’m not one for vegetables, but really there’s only so much vinegar the uninitiated stomach can take. I had another go at the world record sudoku, seeing if I could get into it logically. I did indeed spot a swordfish (the first step in the scanraid solve incidentally) but it gave me no further information. Perhaps I was just tired. Perhaps it really was a monster!

I headed upstairs to the room to grab a quiet 45 minutes to attempt to regenerate. I tried out the various TV hotel channels, coming across things like Bloomberg, CNN, BBC world but eventually hit the jackpot when I found Eurosport with some of the world championship snooker. I managed to catch the last of O’ Sullivan’s title bid, as he went out to Mark Selby. Perhaps I should rewrite my previous analogy for Hideaki Jo! Anyhow, the time soon drifted on to 9.30pm and it was time for the “special programme”.

Nothing initially seemed to be going, and I found myself in the company of US captain Nick Baxter and two-time champion Thomas Snyder – who was solving one of his own puzzles that had appeared in some Japanese puzzle book. His mood wasn’t particularly great – reflecting the underwhelming quality of the puzzles – but he had had a fantastic round A, which given the weightings of the rounds seemed to be the key to a good overall score. However, his eyebrows were raised as the results of round H (the “playoff”) came out. He had made a transposition error and had 6 digits out of place. Even worse, was when he examined my script. I had (in spirit) got the right answer out, but had inexplicably written a 5 in as a 9. I had been given the points. On a comment after his blog post Thomas has alluded to a paper that was marked correct when it wasn’t – and I can exclusively reveal that that was me. There, I’ve outed myself to the puzzling world.

Worse was to come as I mentioned to the pair of them that at least Team USA were very well place in the team competition. Thomas had been on leg 2 and had actually solved the puzzle just to the left of Satan’s 240V iodine secreting rusty jagged testicle vice – thus setting up Team USA as the only team to have finished the relay. However it turned out that there had been a mistake. Although Thomas had equally (in spirit) solved leg 2, he had inexplicably written in a 2 as a 3. And whilst it was nice to know that I was in good company, the gravity of his mistake completely outweighed mine as it meant that the US only scored points for the first leg – the same as the vast majority of the other teams. I thought it prudent to scamper off and join the rest of the Brits.

The special programme was remarkable in that political correctness was thrown out the window. Random competitors were drawn out and the girls competed in putting makeup on a boy’s face; whereas the boys were left to peel potatoes. Utterly surreal if you ask me – but the real Ricky Gervais moment was to come when they were all asked to dance to The Blue Danube waltz – and it turned out this was a little bit too much for the personal faith of the Turkish girl. The “little final” came and went and to be honest I can’t remember much about it. And just as I thought my limits of the surreal were pushed to the limit, it was time to start a round of competitive sudoku. At 11pm.

Round K

Entitled nightmare in Zilina, basically these were 6 hard puzzles, which noone got done in the hour. There was a killer puzzle, which I didn’t do because the cages were dotted in a way as to obscure the visuals of the puzzle, a rock hard diagonal which I had to guess at and even a slightly mental 9×9 puzzle that had split cells so actually you had to put in numbers 1-13. However my enduring memory of the round was the so-called halloween puzzle. Basically an alphabet sudoku (with a fiddly non-adjacent rule to allow for the repeated letters), I started solving and got to a point where I had a non-unique solution. This – especially after round E – made me very angry and I left a rather rude message for the organisers on the paper. One of the translator people – also acting as invigilators – saw this and gave me a wink…this was just as well as I had missed the constraint which said that the word “halloween” had to be visible in the grid. With that satisfied, the puzzle came out uniquely. I quickly erased my rude message!

Anyhow, after that round was all said and done, I was faced with the question as to what exactly do you do at the end of a sudoku solving day that spans the best part of 15 hours? The answer is of course obvious. You go to The Pub. Joining me in the panorama bar at the top of the hotel bar were David, Ariane, Michael, Jason and Times journalist Jack Malvern. The bar itself was something else – stuck right in an 80’s time warp with disco lights, and a singer who was doing her best to croon out tunes that if I’m being totally honest belonged in a porno. On the other hand the 80’s theme was going down very well with Jack and Jason. I could only feebly protest that actually I was born in 1986!

The intention had been to stick around for a couple of beers – and this initially seemed to be the case as David and Michael rather sensibly slunk off to bed. However, the magic word tequila soon got aired, and before we knew it three shots of the stuff had appeared in front of myself, Jason and Jack. This evening was beginning to get epic, as Jack got in a round of shots – Ariane joined in this one – and the fun really began to get started. Some drunk Slovakian came to sit down with us, mumbled something incomprehensible, and then took off to the dance floor. The main moves he and his chum appeared to possess involved sliding about on the floor a lot.

Meanwhile, the people behind the bar had taken a shine to us and were bringing over free shots for us. These were all of completely unknown origin, and we had no hope of identifying them. The most memorable of them was called “the embryo” and essentially did look like an embryo in a shot glass. I’m sure it must have been egg or Bailey’s or something but for all I know it could have actually have been the unspeakable! Now, this was all a little interesting from a personal perspective as it was getting quite late and I was getting a little drunk, and I had to be up fighting fit for a probable World Championship Semi-Final in the morning. However, there was just time for one more round of shots. Absinth.

All that needs to be said on the matter is firstly, that Jason had never had absinth in his 30+ years – which I can only surmise is because the stuff might actually be banned in the US, and secondly this wasn’t the mincey-faggot 50 or 60% volume stuff you get over here. This was the real deal, brought over by the barman who performed the beautiful ritual of burning sugar over the drink. Knocked back down in one was a real eye-opener, and it was perhaps for the best that the bar shut there and then. Although not without a cameo appearance from a statuette of a rather darkly toned saxophonist, which I think we named Tyrone. And with that I’ll end this entry.