#93 - WSPC 2023 recap and practice puzzle set

Last week WSPC 2023 took place in Toronto, Canada! I took part in both events, on the A team for the Netherlands - my second time participating after my debut last year.

I finished in 34th official / 38th unofficial in WSC (2nd NL and up from 56th unofficial last year) and 38th official / 47th unofficial in WPC (3rd NL and down from 42nd unofficial last year). Overall I'm happy to have improved my sudoku ranking and am content to hover around the top 40 mark in puzzles, but I do feel there's still a lot of potential for me to do better. Hopefully I can keep improving at future events. A short breakdown follows of my performance per round for each event, along with what I liked and/or didn't like about the events as a whole and a recap of other fun stuff that happened.
If you're just here for the practice puzzles, scroll all the way to the bottom of the page.

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WSC - Day 1

Round 1 - Opening Ceremony: 400/450 points (tied for 18th unofficial)
A great start for me, much better than last year where I only managed to finish 3 out of 10 classics. I knew what to expect going in this time and finished everything I was targeting and then some more. Only missed the shape sudoku.

Round 2 - Simply Classic: 340/450 points (26th)
Solved all but the 75-pointer, but forgot to fill the last two cells in the 35-pointer. Unfortunately mistakes like these always happen and this will certainly not be the last time we see avoidable errors like this. Still, a strong start that put me ahead of everyone else in NL.

Round 3 - Intellectual Properties: 240/600 points (tied 82nd)
The great start wouldn't last though. After a quick start with the odd/even (65), I ended up spending between 15-20 minutes on the 95-point thermo only for it to break at the end. Couldn't see how to fix it and it rattled me too much. In a complete state of panic I managed to still solve the easier thermo (55), consecutive pairs (90) and palindrome (30) in the last 15 minutes or so. This mistake cost me around 15 places in the ranking, which I wouldn't recover anymore.

Round 4 - It All Adds Up: 250/600 points (tied 48th)
Another poor performance scoring less than half of the available points, but I was expecting this round to be my worst going in. Scored points on both killers and both arrows as I planned, also solved the 75p difference but I ended up having an unfortunate error swapping some of the last few digits and losing the points. Down to 3rd place NL at this point.

Round 5 - Extra Toppings: 375/550 points (19th)
A somewhat decent recovery as I managed to solve everything I was targeting ahead of time without errors. Missed the disjoint, double diagonal and triple diagonal, but I suppose I just lacked pace on the other variants. My performance in general tends to drop off as the day progresses, which I felt like it showed here, but 19th overall is a solid result.

Round 6 - Cloned Classics: 300/450 points (tied 54th)
Lots of finishers this round, and I was kicking myself for not having finished myself as I was easily on pace for the first three of 4 puzzles. I did start out the round solving the first puzzle as a clone within its own grid, costing me a few minutes. My main fault though was just taking way too long to realize the central trick in the last puzzle. Ended up having an error in the first grid of the last puzzle too, costing 50 points.

Round 11 - Too Many Clones (Team): 1240/1200 points (19th)
We did relatively okay, finishing the round, but unfortunately we made an error in one of the clones and re-solved 5 entire grids to be sure we fixed it. It ended up costing a significant chunk of points in bonus time. I liked this round as a mild team round, but would have enjoyed it a lot more if it wasn't planned directly after the individual Clone round so we weren't effectively solving the same thing two rounds in a row.

Round 12 - Put It All Together (Team): 1640/1200 points (tied 5th)
A solid result, 5th place overall. We were all scared of this round, but it turned out to have a lot of information given, bringing the difficulty way down from what we expected it to be. It made for a very enjoyable solving experience.

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WSC - Day 2

Round 7 - Classics, Revisited: 390/550 points (tied 28th)
I was hoping to catch up some of the points I lost in round 3/4 the day before, and classics are one of my stronger points compared to the rest of the NL competitors. I was in the hall warming up at 8 am already (like almost every day) and ended up topping the round over my teammates by 55 points. Decided to just solve in order and ended up missing only the final two puzzles.

Round 8 - Think Outside The Box: 225/550 points (tied 50th)
I wasn't particularly scared of this round going in, but it ended up being my worst points-wise. Spent a long time bookkeeping the initial clues in the diagonal outside to eventually get stuck for too long and give up, and failed to solve both shapes despite attempting them.

Round 9 - Grid-Breaking: 360/550 points (tied 20th)
This round scared many people, but I was feeling pretty confident about it. I'm traditionally pretty decent at irregular grid types, except isodoku which just doesn't click for me and tends to hurt both my brain and eyes. I ended up leaving the star, 2nd isodoku and weave sudoku, solving 6 of the 9 puzzles and topping the round within NL.

Round 10 - Sudoku Sandbox: 235/575 points (tied 63rd)
A disappointing score to end the individual rounds with. Hybrid rulesets are what I started out with when I first started doing sudoku so I was hoping to do well here, but the combinations ended up not suiting my preferences very much. Almost had an additional 85 points, but just barely ran out of time.

Round 13 - Leafs and Stars Assemble (Team): 1716/1700 points (14th)
This round was a lot of fun as it had a high degree of focusing on your individual strengths while still working as a team. We ended up just barely finishing. We probably could have done a bit better but it was still nice to achieve.

Round 14 - Stick To Your Vision (Team): 960/1200 points (tied 5th)
This was a super fun round and would have been one of my favorites, were it not for one large flaw. Many teams stalled on one single puzzle where the break-in was simple if you knew it, but very hard to figure out if you had never seen it before. The break-in lied entirely in the quadrant of a single solver, so if that solver wasn't familiar with the set-up, you were pretty much doomed as you weren't allowed to communicate. Visualising the rest of the puzzle to make some progress in your own quadrants was pretty much impossible. It would have been so much better if the quadrants were divided such that more than one person would be able to make a start in the puzzle. As it was, we ended up looking at the same empty page over and over again, unable to help our teammate who needed to place the first stickers.

Round 15 - Instructionless Sandbox (Team): 650/1600 points (tied 25th)
A disaster score to end it on, because myself and a teammate could not figure out one of the required rulesets. Asking around after the round, many teams suffered the same fate, but I don't think the ruleset used was unfair or anything. It is peculiar that many people were stuck on the same thing, though.

Overall the WSC was a fantastic experience filled with high quality puzzles and well balanced rounds. Apart from the one or two points that I already mentioned I felt could have been better, I probably would have enjoyed some more novelty in the featured puzzle types, but I was also happy just solving what I already knew. A longer round (say, 90m or so) would have also been fun. Comparing it to last year I enjoyed this year a lot more, mainly because the difficulty felt much more balanced throughout.

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WPC - Day 1

Round 1 - Welcome to Canada: 555/600 points (24th)
Starting strong again! Much needed too, as I was not feeling confident about the number placement rounds to follow shortly after at all (rightly so, as we will see). I solved everything except the second TomTom. The high-pointer fillomino took ages and the low-pointer yajilin felt undervalued, but the rest all went smoothly. Solving one of the battleships from scratch in less than a minute at the end was a nice bonus too.

Round 2 - Jacob E. Funk: 210/450 points (tied 61st)
Less than half the points, so pretty disappointing. The gapped kakuro took forever and felt like it should've been more than 85 points to me. Especially in comparison to the Thermo, which was a long solve but felt much easier.

Round 3 - Niagara Falls: 270/500 points (tied 55th)
A scary round heading in, so I was happy to score more than half the points. In the end that turned out to even be a small disappointment as I had an error in the second grid of the Top Heavy Number Place, costing an additional 70 points. Really enjoyed the concept of the round and the puzzles.

Round 4 - Road to GMPuzzles: 160/400 points (tied 94th)
I was not looking forward to this round, and my score shows why. Mental arithmetic is not my thing, and while I put some preparation in, it wasn't nearly enough to feel comfortable solving the puzzles and I lacked pace everywhere. I liked the puzzles I did manage to solve though.

Round 5 - American Stars: 75/350 points (tied 93rd)
This year's disaster round for me. I solved the first 3 puzzles easily, then went on to the high pointer 3-star puzzle. I ended up guessing it early on, but my guess didn't break until very late and I did not feel like reattempting the puzzle. I moved on to the builder instead, thinking I'd be more likely to solve that instead of the double, hoping to salvage what I could of the round. I solved it, but ended up having a pretty big mistake, leading to this round being my lowest scoring round across both events all week.

Round 6 - North American Siblings: 120/350 points (tied 45th)
I liked this round a lot, working on multiple interconnected grids at once is always great fun. Like many others, my feeling at the end of the round was that it would've been perfect if we had anywhere from 5-10 minutes more. All my clones were mapped by the end, but I only managed to finish two grids to completion to collect some much needed points. Many people ended up getting 0 scores.

Round 7: A Galaxy Far, Far Away: 330/500 points (39th)
After 3 rounds in a row scoring less than half the points, I was happy with my result here. I managed to solve everything except both battleships and the 2nd wittgenstein briquet. Great puzzles this round, very enjoyable. Perhaps going for the 2nd minedoku wasn't the greatest choice - it took me a very long time and I feel I could have perhaps gotten better points per minute on the other puzzles.

Round 11: What Is The Meaning Of Aqre: 240/400 points (tied 47th)
I was secretly hoping I'd be able to finish this round but ended up missing the 100 pointer and having a mistake in the 60-pointer. The highest pointer (variant with symmetry) felt like a breeze this round for a change, which was nice - perhaps because I'd already had some practice with it through 24HPC earlier in the year.

Round 12: Stretching Our Legs: 430/750 points (tied 37th)
I was looking forward to this round a lot, large puzzles on the easier side are usually a strong suit for me. If I had been sharper I would have had 650 points - I forgot to shade one cell in the 90-point LITS and had a mistake in the 130-point Nurikabe (which I knew before I submitted, but couldn't see how to tweak in time).

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WPC - Day 2

Round 13 - Islands Of Insight: 385/700 points (tied 45th)
I was definitely not as prepared for this round as some people were, but still did relatively okay. Instructionless isn't my greatest strength and I usually struggle to figure out the inherent properties of given examples (like translating a forbidden pattern to a general snake-like constraint). Fortunately I managed to solve everything I attempted, though, and I enjoyed the puzzles that I did solve a lot.

Round 14 - Melon's Puzzles: 255/400 points (tied 35th)
I was kicking myself for not finishing this round - I had around 10 minutes left for the last puzzle, which seemed like more than enough time to solve it. In a slight panic, I started trying to solve it through guesswork and ended up just making a mess and not seeing the right option in time. Another round where I was 1 puzzle short of finishing.

Round 15 - All Over The Map: 540/650 points (tied 21st)
More large, easy-ish puzzles, and loop is stronger for me than shading, so a solid result for me. I missed only the slitherlink (another round 1 puzzle short of finishing), but this one didn't feel as bad as the previous as I was just a little too slow to be able to finish. The triangular masyu took a lot of tweaking, maybe if that had gone smoother I would have had a chance. My only sour aftertaste with this round is that I didn't manage to solve the only slitherlink in the tournament (for those that don't make the play-offs, at least), my favorite puzzle type. Within the team we were expecting these to be puzzles shaped like continents, but I wasn't really sure how to use that information to prepare. It's good that I didn't, because it ended up being states instead (which in retrospect makes more sense anyway).

Round 16 - The Breadth of America: 475/650 points (30th)
You guessed it, this was another round where I finished all but 1 puzzle, in this case the 140-point exercise. I ended up having a small avoidable error in the 35-point disorderly loop too. Overall I was happy with my performance as I was a bit scared of inturnal and cross border parity loop going in, but everything was smooth sailing in the actual round.

Round 18 - Roger's Bag: 285/400 points (tied 25th)
Hey, look, it's another round where I solved all but one puzzle. At this point I was getting frustrated with myself for getting so close every time, but not managing to actually finish any round. I wasn't expecting to get as close on this round though, as I'm really not good at cave. I wrote practice puzzles for the no 2x2 and diagonal variants which helped and ended up intuiting my way through the 100-pointer, eventually getting about halfway through the final puzzle before time ran out.

Round 19: Holesome Diet: 160/440 points (tied 63rd)
I had no expectations going in this round - I just barely understood the rules well enough to be able to attempt the puzzles. Ended up spending all round on the fillomino set, erasing my full progress about 5 times in total because of wrong deductions, and just had no time left to do anything in the araf set. I feel like I attacked the puzzles in the wrong manner, trying to do the layering from an arbitrary puzzle, instead of trying to identify the bottom layer. Looking forward to post-solving it in a more casual manner, though, as I liked the concept of the round.

Round 20 - Pentominous+: 420/600 points (tied 32nd)
Solid result for me. The practice puzzles I wrote helped a lot. My biggest time sink was the 120-point spiral galaxies variant, which took forever. Ultimately missed the high-point star battle and battleships variants and solved everything else. Super fun puzzles throughout.

Round 10 - Words Can Define Us: 175/500 points (tied 78th)
The round I was least looking forward to of all of WPC. I don't really care for or practice word puzzles, so didn't do great here - I solved the easy wordle, the word search and the scrabble, and I feel okay with that. Obviously not great, but good enough for me.

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WPC - Day 3

Round 8 - Aha Moments (Team): 2280/1800 points (tied 4th)
A fun round, but our feeling after the fact was that it felt almost too easy, and we were convinced we must had done something wrong. My teammate and I solved almost the entire 2nd stage puzzle without knowing the rulesets of our other two teammates. We felt like it would have been more fitting for the larger puzzle to have a larger latin square or even multiple latin square sections.

Round 9 - Red and Blue: 900/1800 points (tied 22nd)
Ah, yes, the coloring round. It was a fun little break, but I didn't care for it much. Looking at the points other teams scored and the fact we didnt finish (we missed about 6 tiles), we were probably being a little too careful with our coloring.

Round 17 - Canadian Summits: 1560/1200 points (8th)
A fun round and we did relatively well, finishing with plenty of minutes left on the clock, although we got outscored by most teams above us in the ranking. Perhaps because I was solving a fuzuli with two copies of the same given digit in a column without noticing for a while. Oops.

Round 21 - Trick or Treat: 1060/2500 points (20th)
We did worst out of all teams in the top 10 by a large margin this round, and it was a frustrating experience for us. We had no 'hunt puzzlers' on our team and none of us had the insight to apply the tricks onto other puzzles in time, meaning we spent about half an hour looking at all the trick puzzles with no idea whatsoever what to do. The concept of the round with collecting the puzzles was enjoyable, though.

Round 22 - Ceremonial Folding: 1540 (optimal, tied 1st)
I did absolutely nothing this round and got carried by my teammates all the way, so thank you teammates! Two teammates did all the folding, with one being particularly strong at it, the other did the optimisation, so I pretty much just sat around and watched in awe.

And that's it for WPC! It was pretty unfortunate that the team rounds all got moved to the final day as these are generally lower intensity for us and provide a nice mental cooldown from individual rounds, but I understand the logistical challenges in organizing an event at this scale. Consequently, days 1 and 2 were long, but fortunately I didn't have a lot of drop-off in my performance caused exclusively by fatigue. 24HPC prepared me well.

My results could have been better if I had more time to prepare before leaving for Canada and spent more time practicing on Wednesday in Canada, but it is what it is. I can't be unhappy anyway, because 38th (the rank I ended up in) is the exact rank I predicted for myself in the tiebreaker question in the Crystal Ball contest. So I guess I'm a winner after all :-) (edit: and apparently I ended up winning the whole thing! Thanks, Tawan :-) )

The puzzles were all very high quality and I don't think I had a single experience where I just did not enjoy a puzzle at all, so my compliments to the author team. I'm not a huge fan of the division into number/object/shading/loop/region - it feels nicer to me to have the option to pick and choose within rounds, but getting to see the playoffs was a fun experience. I don't think I liked this year or last year's WPC much more than the other; both had elements that I really enjoyed and ones that I enjoyed less, but my overall feeling is I loved both and had a blast participating in them.

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So that's it for rounds. There was tons of other fun stuff that happened before, during and after WSPC that I could write about for ages, but as this post is getting really long, the one thing I want to highlight is the speedsetting session organized by Craig.

When I first read about his initiative to host one, I was immediately interested in participating. Just before leaving for Canada, however, I got a new shipment of Nikoli books and noticed I accidentally bought two copies of the new The Pencil Puzzles 2024 book. I reached out to Craig offering to put it up as a prize for the speedsetting, and somewhere along the way I volunteered to judge the entries instead, since competing for my own prize seemed a bit weird. Craig accepted, and before I knew it I had 19 hybrid and variant yajilins to solve during WPC. Some of them were nice quick and easy solves, but many others went all out combining rulesets I would have never expected, and those puzzles took a long time to solve. It amazed me what people were able to construct on paper in an hour. Just observing people authoring in the hall was great fun too; there was a very unique atmosphere in there while the clock was ticking. People crying out in both frustration and elation when their puzzle didn't or did do what they wanted it to, getting actual phone calls with questions about the prompt, being the one to shout "5 minutes left" for once instead of the one to panic upon hearing it, all of it was great.

Finding time and energy to properly attempt them after rounds every day was challenging, and there was also a non-zero amount of transcription errors in getting the puzzles over from collator to judge adding to the time spent on them, but in the end I received proper help both on-site (thanks, Wouter!) and off-site (thanks, Prasanna!) and managed to solve all the official entries right before the playoffs ended, just in time to announce the results.

The puzzles can all be found in the WSPC2023 discord here. They're all definitely worth solving, including the ones that didn't make it to the podium. Unfortunately the puzzle we put in first place turned out to be just barely non-unique, something my teammate and I missed while judging, and I owe an apology to all the participants for missing that. Particularly to the author of puzzle 13, which would have made it to the podium instead. In any case, it was awesome being involved in this and I'm already looking forward to doing this again next time. I've recorded all my solutions here, in case it helps anyone attempting these puzzles.

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And last but not least, my practice puzzles! I did not have as much time this year as I did last year to write practice puzzles, so I ended up focusing only on puzzles that weren't covered yet by others. I wrote 6 puzzles, for rounds 15, 18 and 20. Rules are not included in the links, so you'll need the IB if you want to look at those.

Round 15 - Masyu (Ice) - 3/5 - https://tinyurl.com/ynjyjs3u