Review: World Sudoku and Puzzle Convention

Due to the global pandemic, it was once again impossible to hold a “regular” WSPC. Instead, a week-long online convention was held. As with the German Championship earlier this year, I will drop a couple of remarks while my memory is still fresh. I will limit myself to some general observations and thoughts this time, rather than go over every single round.

I will be critical of certain aspects of the Convention, but before I get to the actual discussion, some acknowledgements are in order to the people who made this event possible. First and foremost, my thanks go to the puzzle authors, and also to the test solvers. The contests were hosted by Logic Masters India, so let me extend my thanks to the people who have been working on their website. Finally, I am sure there are many more organizers and others who deserve a mention and who I am missing right now, so let me just say they have my gratitude as well.

Regarding the course of events, let me start with the bad news. I found it very unfortunate that the fundamental announcements were made at such short notice. I do not care much about minor gaps in the instruction booklets; it just so happens that there was very little opportunity to generally prepare for the Convention schedule-wise. I do not know how others feel about this matter, but it had a major impact on my perception of the WS+PC.

If this had been a live event of the same magnitude, people would have taken a week off (making arrangments half a year earlier or so) and, even without a fully detailed schedule at hand, I am sure the WSPC week would pretty much have their undivided attention. Such is usually not the case for online events, even for those of the highest order. Obviously I can only speak for myself, but in essence I just lived my everyday life and added a few puzzle rounds each day.

Until a week before the Convention started, I had no idea about what other “gatherings” would be there, so I did not make time for any social (or pseudo-social) activities in the WS+PC context. As a result, I simply took part in the two main events and skipped all the Bonus Rounds and Time Trials. I briefly looked into two of the Panel chats some hours later, when they were available as YouTube videos, but did not join in on any of them in real time.

Do not get me wrong. I do not think that I would have taken a week off even if I had seen a schedule a month earlier, and I would probably not have taken part in all the activities beyond the 18 main rounds in any case. Still, I was reluctant (at least initially) to view the Convention as something special. My point is that I was in my usual 9-to-5 routine and did merely a little extra puzzle-solving. Perhaps this is as it should be after all.

Now, about the puzzles. I felt that the puzzle selection was – mostly – very good; the Convention featured a wide range of puzzles and variants, and the mix of puzzle categories was nicely balanced. Most of the rounds were of an assorted kind, not thematic ones. But then, there is no real justification to include a lot of thematic rounds (perhaps apart from traditional reasons). The above is an observation on the Puzzle contest in the first place, but it also applies to the Sudoku part.

It should not be surprising that I liked some of the puzzle styles more than others. The Dim Sum puzzle was the one I would consider the most dispensable. (While the other puzzles of the round were being printed, I had a brief glimpse at the graphics and then, without doing any actual calculations, tried the two which looked like the most abundant ones.) The Mahjong Mazes were also painful, but given the large number of participants from certain Asian countries, I guess it is somewhat fair to include some symbolism that Western solvers are unaccustomed with every now and then.

I came to enjoy several puzzle types and variants which I had not encountered before or which were otherwise unfamiliar (Norinori, Sashigane, Place by Product, Nanro Cave, Index Yajilin, Five Cells). Also, some Sudoku variants (Max Triplet, Coded Pairs, Search Nine, etc.) were more fun than I expected. In some cases I was held back by my lack of preparation; on other occasions I made stupid mistakes. Still, I want it on record that I liked quite a few puzzles which I might not have given a chance without the Convention.

The Skyscrapers round was a disappointment, I am afraid. It is not just the puzzles; I think the entire round concept was flawed. The multi-grid rule set with shared clues may work reasonably well for a small number of puzzles, but it is simply not rich enough to support nine individual grids of the same size in a single large pack. I would have preferred a slightly larger variety in this round.

This brings us to the matter of results. The Skyscrapers were the only round where I had a very clear ambition. Apart from that, I hoped to end up in the Top 20 in the overall table of the Puzzle Convention (i.e. the Top 10 outside of Japan), but it was not to be. In the Sudoku event I missed the Top 50, but since I never was particularly good at Sudokus, it is no big deal for me. All the results should be taken with a grain of salt anyway, considering that some excellent puzzle solvers did not participate at all.

Philipp and Martin ended up ahead of me, and it seems we have a new star in the German puzzle solving sky: Christian König (nickname CJK) worked his way up to one of the German top positions in what appears to be less than a year – at least I do not recall seeing him in earlier German championships. Among other things, it means I can barely hope to get a spot in the German B-team, let alone the A-team, should I eventually make another attempt to qualify for a future WPC.

In the international competition, the number of participants who finished ahead of me is not as scary as the margin by which the top solvers win these days. Ken, Walker and Freddie are truly a league of their own these days (I am pretty sure even Ulrich will agree with me on that). The Sudoku results are perhaps not quite as telling, although there is again a considerable distance between rank 3 and 4.

Finally, some words on my solving strategy. When I restarted this blog, I wrote about contest strategies and “comfort lists”. Well, I barely did any preparation beforehand at all, and it was usually my approach to start with the expensive puzzles – except in cases when I really disliked the puzzle style in question. In general this seems to work well for me, unless I make errors and break the puzzles (which, I regret to say, happens far too often these days).

There is something that bothers me, though. As mentioned above, there are three participants who are so far ahead that they can usually complete all the puzzles no matter what (and I am not in a position to judge strategic matters in their case). Among the mere mortals, I cannot help but feeling that the latest contests seem to reward bifurcation, intuition and – occasionally – sheer guesswork over the application of cold logic. At least it appears to me that every hard puzzle I attempt can eventually be cracked faster by means other than logical solving techniques.

An extreme example, to give you an idea what I mean: In my very first round of the Convention, when I was still trying to solve them logically, I broke four Sudokus in a row; this took more than half the round and cost me 150 points or thereabouts. On the other hand, when I looked at the Big Tents puzzle (from the Triple Jump round of the Puzzle Convention), I decided to just place a dozen of tents where they fitted best with the clues and did not obstruct each other. This took no more than 90 seconds, including printing, and was rewarded with an instant 80 points. A week later, I still do not know what the logical solving path looks like.

This is regrettable, but let me clarify. My perception is not limited to the WS+PC; it seems to apply to most contests I have taken part in lately. Also, it may be just my own approach, and others may feel completely different about it. And still, I am confident that I am not alone with this. Not too long ago, Ulrich has expressed a similar sentiment: that it is a pity he cannot fully appreciate puzzles he solves under time pressure, because the most successful route in a contest is usually not the most beautiful or elegant one.

Anyway, the Convention confirmed that I am no longer a match for the top solvers out there, unless I have a very lucky streak. (It may even be that I am making a virtue out of necessity, playing for my strengths when it comes to intuitive solving. Chess players who have seen my more recent games will know what I mean.) Perhaps I will get another chance to mess with the best; in particular, I would really love to see Toronto. So long.

6 replies on “Review: World Sudoku and Puzzle Convention”

I feel quite honored to be mentioned in your blog 🙂
For your information: Even though I loved solving logic puzzles since I can remember, I started with competitive solving when I discovered, which indeed was about a year ago (October 7th 2020, to be precise). This could be the reason why you cannot recall seeing me in earlier championships 😉

In fairness, many other prominent solvers who have risen in a relatively short period of time already had a similar background, either in some other kind of puzzle-solving or in a related area (e.g. mathematics). So, no real surprises there 🙂

I think there’s much to be said about the communications about the convention – but I’ll limit myself for now by observing that this is a separate task from actually organising and running the event. In some sense the communications when running an offline event take care of themselves – the WSC and WPC have a captive audience, so that when venues are booked and confirmed you simply work backwards from that point and the organisers and participants alike know exactly where they stand. I don’t know what happened with the convention, but I can easily imagine that with a deadline not tied to a hotel booking, procrastination on the project set in and that most of the event planning and work happened in a matter of weeks leading up to the event. I am merely speculating, but what other explanation for the radio silence can there be?

Whatever did happen, I think what is fair to say is that any WPF oversight of the event appears to have been minimal, and it does make you wonder what they are all doing, and why it is they put themselves forward as so-called leaders of the puzzling community whilst simultaneously demonstrating such little interest in this community.

The other thing worth touching upon is with the top puzzle solvers. I think we’ve briefly touched on the sheer amount of practice these guys are getting, most of it online, and it seems like the perfect way to hone your intuition. Of course these top guys are top logical solvers as well, but this is where a competitive edge starts to set in.

I’d agree there has been a bit of an arms race in difficulty recently. There’s probably a lot more to say on this subject as well – but I think the motivations of puzzle authors (in general) these days aren’t really the same as they have been in the past.

Regarding the oversight issue, this judgment may be a little harsh. Obviously I do not know either what the WPF officials are doing, but I would guess the lack of communication was mostly due to a lack of experience with hosting online events of this magnitude.

David suggested in the UK forum that the two formats – real-life WSPC and online convention – should be used alternately, and I agree that is an interesting idea. I guess there would be some significant changes in the event of a second convention, based on the experiences from the first one. Perhaps we should view this simply as part of the learning curve.

Thanks for the reply Roland – I was going to follow up my original comment as I don’t think it was very clear that my opinion is, all things considered, that the convention was successful and the organisers themselves should be very proud of what they’ve achieved. That’s definitely worth adding to the record!

On the point of oversight, yes perhaps that sounds harsh but I don’t think it’s unreasonable. I recall the meeting back around last March or April where the online idea was first mooted, and that an update was promised a month later. That never materialised, and my understanding (which admittedly might have been wrong) was that as of late July when I blogged about the subject that no progress had been made. (

I am in two minds about making an online convention becoming a regular occurrence. Mostly, being able to meet up in person every year has become something very important to me and I would be saddened if it were something that happened less frequently.

On the other hand, I do think there is some potential for some kind of online events like this in the future. I agree that there are many things that would look different from this first incarnation. Certainly the sheer scale of the event (counted in number of puzzles) was truly remarkable, and I don’t think you’d need something quite as intense as that. Also, I think there is lots more room to move away from the established competition formats and experiment with new ideas. And anything that could somehow bring to life a sense of team/collaborative solving would be immensely welcome!

The only other point on oversight reveals some hypocrisy on my part. Had the WPF tried to do any kind of oversight of my own work leading up to the WSC and WPC in 2014, I suspect my reaction would have been dismissive and uncooperative, to say the least!

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