#107 - WSPC 2025 recap and practice puzzle set

WSPC and 24HPC 2025 have concluded!

This post will recap only WSPC - 24HPC will be in a different post, probably in a few days after I finish post-solving the rounds. 

This was my 4th year in a row participating in WSPC. I was on the A team for Sudoku and on the B team for Puzzles this year. 

I finished in 29th unofficial in WSC (25th official, 1st NL and up from 54th unofficial last year) and 38th unofficial in WPC (2nd NL, same rank as last year). 

Last year I wasn't happy with my WSC performance. This year I dedicated almost all of my preparation time ahead of the championship week to sudoku, and my performance felt better because of it. I still feel like I performed rather poorly in a couple of rounds, especially on day 1, so (as always...) there remains plenty of room to do better. Overall though, breaching the top 30 and securing the top spot in NL feels like a solid improvement over last year.

Because my focus on WSC inevitably meant a lack of preparation for WPC this year, and because I was struggling to solve any of the practice puzzles on the rest day between the two events, I felt like I was certainly going to drop compared to last year in the puzzle ranking. I managed to maintain my rank and achieved some nice personal bests along the way though, so I'm pretty happy with how WPC went as well.

A short breakdown follows of my performance per round for each event, along with what I liked and didn't like about the events as a whole and some other afterthoughts.

If you're just here for the practice puzzles, scroll to the bottom of the page.

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WSC

Round 1 - Road to Eger!: 175/300 points (tied for 39th unofficial)
A fun round to strategize for ahead of time as it only required one puzzle to be solved per page. I went for a mix of low and high pointers, mostly selecting to my strengths. Unfortunately I was careless with the carry-over deductions and erased a full grid after making a wrong elimination using the Surplus grid, meaning I ended up a few minutes short to finish the last puzzle. This round was one of my favorites, but I think I would have put it a bit further on the day - starting the tournament with a strategy-heavy round that also forces all solvers to start with a rather obscure variant felt like a bit of a weird start to the event. 

The culprit: I wrongly eliminated 5 from the circled cell and used that information in the other puzzle I was solving on the page.

Round 2 - Classic Sprint: 84/200 points (53rd)
My classic round was very poor. 1 puzzle with errors and 2 started but unfinished puzzles meant my performance was much worse than I would have liked. I struggled to get momentum going, in part because of the very first puzzle which felt like one of the harder ones in the round.

Round 3 - Parity Party: 252/400 points (tied 16th)
I practiced a lot for this round across all variants, so I was glad to rank in top 20. One error cost me 8 points, which would have put me 2 spots higher up the rank, but nothing to be too upset about in here. 

Favorite puzzle: Odd Labyrinth

Round 4 - Halved Squares: 215/500 points (tied 44th)
I also practiced a lot for this round which doesn't really show from my rank, but I'm fairly certain it would have been much much worse if I hadn't. I ended up liking this much more than I thought I would, maybe because it was one of the few rounds that had novel types. It very much felt like the large Outside should have been the most valuable puzzle in the round (not because it was that hard, but because it was slow and took extremely long - in my case certainly much longer than the large Thermo and Killer). Going for it probably ended up hurting my score quite a bit.

Favorite puzzle: 9x9 Thermo (post-solved)

Round 5 - Small World: 330/390 points (tied 19th)
I also really liked this round and was pretty well practiced for it (thanks to a similar puzzle posted in the CTC discord server a few years ago and another from 2009 24HPC). At first I thought having the Irregulars was weird, but they were a nice way to salvage some points if you got stuck. I ended up completing both linked grids and two Irregulars. The second linked grid was definitely a lot harder than the first, so them having the same points value was a bit strange.

Round 6 - Calculated Fun: 177/450 points (51st)
Ah yes, the math round, my worst enemy. I didn't do too bad this year thanks to adequate practice, but could have done better: I failed to solve the Killer despite spending at least 5-7 minutes on it (very undervalued puzzle!), had a last-minute guess on 0-8 Arrow go wrong and flipped two digits in the Upper Right Heavy Killer. Post-solving did thankfully tell me that I definitely picked the right types to focus on during the round.

Favorite puzzle: Before Nine - a nice theme and fun, gentle solve

Round 7 - Spot One: 401/400 points (137th)
I'm still kicking myself over this round. Despite preparing sufficiently, I spent upwards of 20 minutes during the round not doing anything because I gravely misunderstood the rules while solving and thought I had broken the puzzle, only to find I was completely fine and no more than 5 minutes away from finishing the entire time. At the same time I was stressing out from the endless sound of "Finished!" all around me, until I eventually decided to submit a solution that I thought was wrong, but which was in fact perfectly fine. In the end, this is still only the first WSC round I ever finished, and I did so with exactly 1 point of bonus! (... actually 50 points and some points subtracted from a small error, but who's keeping track)

Round 8 - Circle of Sudoku (Team): 2016/1800 points (22nd)
Not much to say here - I enjoyed this round for its relative simplicity. I also felt like I got to work on every grid at least a little bit, which doesn't always happen in team rounds. I ended up writing one wrong digit somewhere, so I cost my team some bonus - sorry! 

Round 9 - The Patchwork Challenge (Team): 1140/1800 points (18th)
While the concept of this round was also fun and I enjoyed it quite a bit, it did feel rather messy because of the small tables and the amount of papers we had to deal with and keep track of. We got nowhere close to finishing this one.

Round 10 - Classic Uphill: 175/400 points (tied 42nd)
This was my least favorite round this year. I had decided well ahead of time that I would go in with a bifurcation heavy strategy, even more so than usual, and I ended up solving all 6 of the puzzles I did through heavy trial and error. From post-solving it seemed like this was the right strategy as the round felt very unbalanced, with a few of the puzzles apparently having no reasonable logic (especially the low-point 2nd one).

Round 11 - The Sudoku Pyramid: 440/300 points (tied 10th)
This round however was very enjoyable. It was a simple, fun and novel concept and the puzzle had several ways of attacking it, so strategy played some role too. I achieved one of my best ever results in an individual round, just barely scratching the top 10 with 14 minutes saved. 

Round 12 - Sudoku Mix: 534/800 points (15th)
I also felt quite good about my performance in the long round this year and I'm very happy with my result this round. Instead of trying to blaze through every single puzzle, I went more slow and steady, focusing on being consistent and not making any sloppy errors. The only error I did make was in the last minute, trying to hastily secure the easy 15-point GT Odd/Even. Thanks to the error leniency, I scored 9 points instead of 0. I could not think of a better puzzle to get partial points on.

Favorite puzzle: Outside 234 (during the round) and Coded Pointing Evens (from post-solving)

Partial credit, in all its glory, netting me 9 points for this wrong solve

Round 13 - Weakest Link Revised (Team): 1650/1800 points (tied 4th)
Mixed feelings about this round. On the one hand I like solving independently, on the other it just felt like another individual round. I think overall I like a round like this as long as the other rounds involve more teamwork. Unfortunately I messed up on the Ordered Distances, misreading a set of clues and erasing the full grid with 80% solved already, leading to me not completing the Outside of my set and delaying my team on their solves. Another teammate also missed the Outside, so I felt like we must have done poorly, but somehow we are tied for 4th place in this round. I guess our chain is balanced well? 

Round 14 - Utter Chaos (Team): 2240/1800 points (tied 6th)
My favorite team round - I really enjoyed the idea. It turned out we could just solve independently on whichever layer we wanted though by simply layering all three sheets and lifting the appropriate corners, which was nice during the round but in retrospect detracted from the experience a bit - it would have been great if the team had to coordinate on which layer to solve at which time. Still though, great round. 

Closing thoughts:

- Puzzle quality this year was great. I think only in the hard classic round quality was lacking a bit - none of the other rounds had anything I strongly disliked. Even types I usually avoid like the plague, such as Greater Than and Fraction, were fine and enjoyable for me in my post-solve. 

- Points valuation was also solid this year, with only a handful of wrong calibrations. Maybe two or three high value puzzles should have been a bit lower (Termination, 0-9 Kropki, the large Halved Square Killer come to mind) and a few lower rated puzzles somewhat higher (R6 Killer, the large Halved Square Outside and the 2nd First Seen Odd/Even), but overall wrong calibration was minimal and did not detract much from the solving/competition experience for me.

- I think the only big miss was the length of the Spot One round. Getting up to 35 minutes bonus on a 50 minute round feels like it shouldn't be achievable, and it probably made the round more important to the ranking than it should have been. 

- By far the best improvement for me this year was partial points being available. I always find it so demoralizing to lose a ton of points because I forget to fill in two cells or accidentally swapped the last two digits. This year, in total, I made minor errors on 6 puzzles, worth 225 points. Partial points means I still got 138 points instead of 0, which accounts for quite a few spots on the ranking! At the special awards ceremony, an award was handed out for most points saved: 183 across 6 puzzles. It makes me wonder... Did I actually get close to winning an award? Anyway, I really hope future organizers keep this change. 

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WPC

Round 1 - Welcome to Eger!: 390/700 points (tied 44th unofficial)
Sadly, I didn't manage to replicate my strong rank 8 opening from last year. Not that I was expecting to, anyway. I did alright this round, though I threw away 105 points - 15 from a silly mistake on the very first puzzle and 90 from being just a minute or so short of getting the 2nd Star Battle Builder in time.

Favorite puzzle: Honestly, probably the Scrabble! The other puzzles were all nice too, but flipping through the booklet this one strikes me as the most memorable now.

 Don't lift your pencil challenge anyone? I failed :(

Round 2 - Evergreens: 1100/1750 points (24th)

Like every year, I was hopeful the Evergreens round would be one of my best rounds. Last year it turned out to be a disaster, this year was much better. I do have an unfortunate one-cell error in the 2nd NFIAR costing 75 points and wasted a good amount of time fixing an error in the big Masyu, but overall I feel happy about how this round went.

Favorite puzzle: The 2nd Castle Wall

 Ouch (75)

Round 3 - Hitori Variants: 475/950 points (tied 54th)
This round turned out less scary than I thought, mostly because I opted for the lower point puzzles rather than the high-valued Fillomino hybrids. The way those solved reminded me a bit of the Splitter puzzles from last year, which did not go well for me, so I think it was ultimately the right call. I wasted a lot of time restarting one of the classics multiple times and have an unfortunate 85-point error on forgetting to extend the last shaded cell into a domino on the 2nd Domino puzzle, so that's the first 3 rounds not solved cleanly now.

Favorite Puzzle: The first Fillomino + Hitori, from post-solving. Lots of fun steps in that puzzle.

Ouch (85)

Round 4 - Quad Puzzles: 455/900 points (48th)
One of my favorite rounds of the tournament. I was really looking forward to this round, so it's a bit of a shame I didn't do better. I didn't have any errors or significant time-wasting, so I think it mostly came down to strategy. The Battleships and Statue Park scared me going in, so I opted for the Skyscrapers during the round instead, which took me forever. After post-solving, I feel confident I could have done both the Battleships and Statue Park in the time I did the Skyscrapers. Oh well, at least the round was clean for me.

Favorite puzzle: Square Jam, but surprisingly also Easy As!

Round 5 - Fish & Ships: 250/500 points (tied 155th)
Ouch, 155th isn't good. Unfortunately I put an extra copy of a two-cell ship in the first Battleships grid, which made matching the grids impossible. I spent the majority of the round not understanding what was wrong, at one point even considering if it was possible my papers were cut wrongly. With some 5 minutes to spare I found my error and managed to solve another grid, but it wasn't enough to salvage my round. Still though, the round was cool and I enjoyed completing it in post-solving.

Round 6 - Tapa Mastermind (Team)
Unfortunately this round got cancelled due to an error. I had spotted the error in our grid early on during the round and thought I was going crazy after erasing the grid containing it and the adjacent grids multiple times and not being able to fix it, much to my own and my teammates' frustration. There's not much more to say about it other than that I feel very sorry for the organizers but think they ultimately made the right call. I am however very much looking forward to post-solving the round with the correct clues - I'm sure it'll be great. 

Round 7: Walk 2025 (Team): 890/2250 points (22nd)
So.. many.. rules.. I didn't really start prepping for the team rounds until the day of the actual rounds and hastily made a cheat sheet for this one with all the rules in one of the breaks. I managed to solve large parts of quite a few grids, but also didn't touch many others, and as a team we didn't get close to finishing the round. I think the round is really cool though, and I will definitely be post-solving the full round by myself in the near future.

Round 8: Across the Stars: 465/1150 points (tied 58th)
Another great round. Star Battle just goes so well with so many puzzle types, and this was one of the most enjoyable rounds for me. Another unfortunate error though - this time I forgot to place the last star in the 2nd LITS, costing me 100 points and 25 places in the ranking. I also struggled quite a bit with the 2nd Masyu, but don't think I would've gotten many more points if I hadn't. 

Favorite puzzle: The 2nd Aqre (from post-solving) - intimidating points value, but nothing too bad and a very fun solve.

 Ouch (100)

Round 9: Assorted Puzzles: 785/1900 points (tied 45th)
I have to admit I was not really looking forward to this round - my strategy had me optimized for only 900 or so points, with the rest being stuff I didn't want to solve or was too unfamiliar with. I ended up doing alright, securing most of the points I wanted to. Not my favorite round, in part because of the puzzle selection but also because a large portion of my time went into bashing through high pointers.

Favorite puzzle: Probably the first Hungarian Numberlink, although I haven't post-solved everything yet.

Round 10 - Nemo: 365/500 points (tied 19th)
With this being a Dutch genre, we had a lot of practice puzzles available (I found some 20 of them in WCPN archives) and therefore maybe a tiny advantage? I think it shows, with this being my 2nd best individual round by ranking. I decided to warm up with the first page and then solve backwards, which was a good call - I had to restart the first puzzle because I was using the wrong range. I would have hated to have made that error in one of the valuable puzzles.

Round 11 - Eger Castle: 440/450 points (53rd)
I really enjoyed this round. I think maybe I would have liked to have seen a different number placement genre instead of two Easy As, but it didn't take away much from the enjoyment. I finished with 10 minutes left, got way too excited about finally having finished a WPC round for the first time and ended up submitting with a very avoidable error. It cost me 60 points plus 50% of my bonus. I would have been 21st place. Sad.

Ouch (60+50 bonus points = 110)

Round 12 - Hexa Hungary: 430/400 points (tied 49th)
This puzzle will forever be Uniqueness: The Puzzle in my head. I was going about it methodically when I heard the first contestant in my proximity say "finished". I looked down at my grid and had only about a third filled in. I mumbled "what the hell" and from then just went with every uniqueness deduction I could find, needing to tweak only tiny bits at the end and finishing with 3 minutes to spare. A bit of a weird experience, but still a pretty enjoyable round.

Round 13 - Pangaea Proxima (Team): 1160/2000 points (tied 20th)
I enjoyed the puzzles I solved in this round. I did the Country Road, the Spiral Galaxies and the Double Choco/Ice Walk. I didn't touch any of the other puzzles and we never made it to the final puzzle, so I feel like I can't say much about the round as a whole, but overall I think leaning into permacultures this heavily is a cool thing.

Round 14 - Solar System (Team): 2300/3000 points (tied 12th)
My experience this round, like in the Tapa round, was also a bit tragic. Virtually no preparation time again meant I was not feeling optimistic about my ability to solve much. I started with the Simple Loop and wasn't able to make much of a dent. I spent the remainder of the round on the Fillomino, first struggling to understand the topology and then getting walled by the unfortunate uniqueness issues. My teammates did well on the other puzzles though and we ended up doing quite alright. The mechanic of the round was really cool, but I felt like some of the puzzles should not have been as hard as they were. The grid shape and rotation aspect made it more than challenging enough already.

Round 15 - Singularity: 480/900 points (34th)
Another round I was very much looking forward to! Even if at times scanning for negative constraint got a bit tiring, this was still a very enjoyable round for me. I probably shouldn't have gone for the Skyscrapers given how long the Quad one took me and instead should have done the Bosnian Roads, but other than that the round was fine and clean for me.

Favorite puzzle: The 2nd Compass (with 1 clues) - no way I would have gone for it during the round, but the post-solve was great.

Round 16 - Coded Puzzles: 610/750 points (tied 44th)
This round scared me and I genuinely thought this could have been a 0/very low point round for me, but I was very happy to complete all but the final 3 puzzles and get the full cipher right. I am also grateful I was told a helpful shortcut in the Products deciphering ahead of the round - it ended up saving me quite some time. I can't quite place the round in my favorites because of the selected genres, but the design and execution was very solid and I enjoyed solving it much more than I thought I would.

Round 17 - The Casino: 485/1050 points (tied 80th)
Another scary round. I probably should have just stuck with the Dice Pokers, because I at least practiced some of those. Instead after solving the first 3 I wanted a change of scenery and spent way too much time on Domino Construction and Darts instead, neither of which I'm particularly capable at. A poor result, but nothing I didn't expect and no errors, so I didn't feel too bad about it.

Round 18 - Full Loops: 800/600 points (tied 7th)
And then it was time for the last round, the one I was looking forward to most of all. This just had to be the round I would perform well on. The entire round went super smooth and I ended up finishing with exactly 20 minutes left, securing 7th place - my best individual ranking to date. I don't think I will top this performance any time soon. I submitted without checking, which probably was an extremely poor decision and which kept me in suspense for a good while, but it didn't end up biting me. 

Probably the highest you'll ever see me!

Closing thoughts:
- First off, some well-deserved praise. We all fully expect the Hungarian team to do a stellar job when it comes to organizing puzzle contests, and they certainly pulled it off again. Great puzzles, great variety, great structure and overall a great tournament. One of my favorite WPCs I've been a part of.

- It's a shame two of the team rounds had issues. In my experience both as a competitor and as a WPF board member, I feel the way the organizers handled it was the best they could have. The impact was kept to a minimum and as fair as possible, and I don't think either error ended up detracting all that much from the tournament as a whole.

- I loved the concept of all the team rounds and I regret not preparing for them more. I feel like I could have gotten a lot more out of them both on a personal enjoyment level as well as progress for my team during the rounds.

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That's all for the main events! As always I loved being part of both events. Thank you to all the organizers, authors, judges, volunteers and anyone else involved for putting on these great events. That leaves just some other more general and random topics to talk about:

First off, Crystal Ball! Having won this fun side event two years in a row, I felt like there was some pressure on me to do well again (admittedly this was probably imaginary). Full results have not been posted at the time of writing, but the winners were announced at the WPC award ceremony and unfortunately I did not even make it to the top 3 this time. I'll do better next year. Also, I featured as the tiebreaker again (guess my unofficial rank in WPC). Last year I wrote: "I guessed 39th. I finished in 38th. Amusingly, 38th was also my guess, my official WPC rank and my unofficial WSC rank last year. If anyone needs inspiration for what to guess next year, there you go." This year, I think I guessed 36th, because it felt wrong to not give myself an improvement. Of course, I finished 38th again... 

I also feel obliged to congratulate Freddie Hand. Not for his WPC victory, but rather for something much more important. After the awards ceremony, we held our long-anticipated 1v1 on 10x10 Word Search, which we have been battling on for years over in the CTC discord. In a nail-biting best-of-five, he managed to come out victorious 3-2, beating me by just 3 seconds on the last puzzle. So Freddie, congratulations! I look forward to the rematch.

And finally, some more afterthoughts about the week as a whole:

- Last year I wrote: "The coffee machine outside the competition hall was a godsend." This year I felt we got taunted with the opposite, with a bunch of coffee machines always present outside of the competition hall but rarely turned on except for during the scheduled coffee breaks. Not to mention the lines for the two machines at breakfast...

- The hidden award ceremonies were an absolutely hilarious addition. While it seems like it may lose its charm if it becomes an expected/mainstay part of the events, I certainly hope we'll see more of it in the future.

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Lastly, here are my practice puzzles for this year. None of them should be terribly difficult though some may contain a few tricky steps. Rules are in the links or can be found in the IB.

04.02 - Quad Tapa-Like Loop - https://tinyurl.com/24z9w26g

04.04 - Quad Square Jam 1 - https://tinyurl.com/2bgz5ry9

04.04 - Quad Square Jam 2 - https://tinyurl.com/27z4ucpn

09.09 - Masyu (Crossing) - https://tinyurl.com/28zt99kq

03.08 - Hitori (Nonconsecutive) - https://tinyurl.com/22umekjc

15.10 - Slitherlink (All 1s Given) - https://tinyurl.com/2yfxwdl5

15.10 - Slitherlink (All 2s Given) - https://tinyurl.com/22tvrwka

15.10 - Slitherlink (All 3s Given) - https://tinyurl.com/298re6xn

18.08 - Midloop + Symmetry Regions Loop - https://tinyurl.com/25jk6b3n

18.05 - Masyu + Symmetry Regions Loop - https://tinyurl.com/24xy6qms

18.15 - Masyu + Midloop + Symmetry Regions Loop + Equal Lengths Loop - https://tinyurl.com/ytohztjg