Community Building

This is a bit of a ‘random thoughts’ kinda post. But before I go on, I want to share that my parents got me this T-shirt and I love it:

Anyway, the main reason for this post is, I’ve been thinking about the difference between casual puzzle solving and competitive puzzle solving. Soon I’ll be starting the 2023 editions of Sudoku Mahabharat and Puzzle Ramayan, and the WPF will start the 2023 editions of the Sudoku GP and Puzzle GP. There are competitions galore online and maybe some offline too as we start another season leading up to the World Championships. *Edit*: I shouldn’t mention all this without mentioning the lovely beginner-friendly contest this weekend on LMI, PANFOPCWHTTAPA 3. The first two editions were great for newer solvers looking to learn new puzzle genres and get into competitive solving for the first time. Check it out!

This process, largely, ignoring small mishaps and challenges here and there, has been carried out quite smoothly in recent years (in another discussion it may be worth actually appreciating what we are able to do as a community year on year with little to no monetary benefit and a heavy lack of personnel in some cases) and I have confidence that that will continue.

However, this post is for discussing other things we can do, to keep the casual puzzlers component of the community involved through the year to a similar extent. I’m very interested in exploring this side of things more. Over recent years I have been trying to capture people in different ways. One big way is trying to expand our author pool for SM and PR and give new and young authors a chance and platform. Puzzle construction doesn’t involve the same pressures of competitive solving and is probably more accessible in that sense for those who are interested in the hobby to keep in touch with it meaningfully.

Another way is to hold more casual mini-events as part of our National Championships. During the offline Indian Sudoku Championship there was a simple team round I ran after the main competition while the organizers were checking, where groups of 3 got together to figure out the connection between some Sudokus and try to solve them together. Similarly, during the offline Indian puzzle Championship, I simply put together groups led by some prominent authors of our community, to teach people the processes involved in writing puzzles. The aim of these side events (other than giving the checkers time to put out the results) is to introduce a social component within the experience.

The last way, which I don’t see enough of (I may just be missing it) across the community and probably want to focus on more here, is to hold meetups regularly. Since India is a large country, we mostly plan meetups specifically for Mumbai, the city I live in. The first meetup I had in Mumbai, was basically just a two-person hangout where I helped another solver get through some tough Sudokus. This was many years ago, and since then, with that other solver’s help and others along the way, we built a regular functioning group with monthly meetups in the area.

After the obvious gap caused by Covid-19, we are now rebuilding this meetup culture. We have a stable venue and a consistent agenda comprising of:
1. Casually start solving some (hopefully) approachable Sudokus that vaguely escalate in difficulty while I float around helping where needed, but also get aided by the stronger solvers who attend these.

2. Introducing and teaching a new non-Sudoku puzzle type.

3. Having a team-solving round from some past competition, trying to group more established solvers with newer/casual ones.

The feedback I’ve got from the participants is overwhelmingly positive, and over the years its given some casual solvers a good way to stay connected. It also gives some of them more encouragement to participate in competitions, knowing that the social component carries forward even if they’re not necessarily contenders for the top positions.

The other, more unexpected positive I’ve seen is the variance in demographic. While most of India’s (and the world’s) top solvers are males around 25-35 years of age, the Sudoku meets I conduct have many regular female participants. I can’t help but feel there’s something there, for whatever reasons, with casual solving being more appealing to female puzzlers than competitive solving. I remember conducting a meet pre-covid where there were 22 participants and 20 were female! The demographic has leveled out more post covid, but it is still usually a good ratio.

These meets are pretty easy to conduct. Find a local cafe that allows for group meetups, use some selection of puzzles from an old LMI set or GP set or WSC/WPC set and just get together and interact while solving. It probably helps to have some solvers around who are more established and can help, but it is quite doable without that too.

I’d like to see more offline meetups in different places. I think it definitely benefits the community in ways that competitions do not and goes hand in hand nicely with the competitive part.

I’d also love to see other suggestions to tap into casual puzzle solving audiences and keep them engaged. There have been some good attempts, with Tawan’s quizzes and contests, the Puzzle GP’s experiment with a casual section, etc. which are good ideas to build on too.

I’ll end this post with photos from our most recent meet, where they surprised me with a cake and a small celebration at the end of the meet to commemorate my WPC performance. It was a fulfilling and heartwarming end to the meet and shows that we are building a pretty cool community with these meets.


WPC 2022 Recap: Silver Solver

I loved this year’s WPC in Krakow. Even without a ridiculously awesome personal milestone, it was one of my most enjoyable WPCs. It’s a pity that I found the WSC underwhelming or we may have two recaps, but I don’t want to dwell on it much right now. Also, there’s been a delay in getting this published as I fell ill the moment I got back (just something that frequently happens when I travel to a colder place, because I’m way more suited to that place, get comfortable there, and then have trouble adjusting back to the climate here).

Anyway, my ranks prior to this year at the WPC event were 94th, 46th, 24th, 23rd, 19th, 18th, 20th and 16th in that order from 2011 to 2019. The usual joke I made was that I keep climbing slowly (lets consider that 20th as a blip) so in 15 years or so, the champions should beware! I only ever meant it as a joke, I thought I was capable enough to get into the top 10 in a good year but I thought it capped there. Yes, I’ve gotten better ranks than that in the GP but I have always felt the GP has a lot of unknown factors related to people’s home setup, internet connections, familial obligations, etc.

Heading into this year’s event, I inwardly got more hopeful when I got to know the playoffs were for the top 12 + Wildcard rather than top 10. More chances at a playoff, I thought.

…so ya, quick spoiler for those who don’t know and didn’t track it from the post’s title, I finished 2nd in the WPC. Here’s how that happened:

Round 160 minutes – 450 points My score: 400

Round 1 had 10 classic puzzles, and was named Countdown. The name telegraphed the theme and the note that the Ripple Effect could have empty spaces to make disjoint grids telegraphed that there’d be a message at the end of the countdown too. As expected, the puzzles started with irregular grids that made 9 down to 1 with the last puzzle making a “GLHF”. Not that any of this gave much advantage while solving of course. I figured that since the total points of the round was less than 10 points per minute by a significant margin, this might be a finishable round for top solvers. However, after the difficulty standards of the WSC I was still cautious about that.

The round started and I took a look at the 85 point Ripple Effect. It looked approachable so I started with it, and it was nice and smooth. I then started going backwards, and promptly broke the Slitherlink. I quickly moved on since I didn’t yet know how finishable the rounds would be, solved all the other puzzles at a good pace, and came back to the Slitherlink with just under 10 minutes left. However, I continued to break it. I’m sure there’s some dumb thing I was repeating, but I couldn’t see it and I ended up missing the Slitherlink. A lot of solvers I’d consider my competition for the playoffs finished this round. 15 of them had no errors. Ken Endo had an error and lost a humongous bonus. I was 18th (official) after round 1, and was kicking myself over the Slitherlink, but we move on.

Round 230 minutes – 300 points My score: 250

This round had 7 Araf puzzles (3 Classics and 4 variants) and they were all by Serkan, which probably gave me a slight edge having solved so many of his Araf puzzles before. I don’t know how much or whether that edge contributed but I finished the round with 1 minute to go. Unfortunately, I had an error in the Different Neighbours variant (a proper solving error where I had two 4-cell regions next to each other) and that lost me 60 points (50 for the puzzle and 10 bonus).

One thing I still can’t figure out though, is why these are marked with 7s by the checkers. I forgot to ask.

Anyway, 5 people finished this round without errors, but I still did well enough to climb to 14th.

Round 3 90 minutes – 900 points My score: 820

This round featured 32 puzzles from 8 new-ish puzzle styles that had originated mainly on the CTC and Puzzler Club discord servers. I’d solved some of them before but most of them were new to me too. I’m mildly active on those discords but I never got to solving some of the ideas. Shoutout to the authors, this was my favourite round in a WPC full of enjoyable rounds. I always love new puzzles at a WPC but putting it together in a 90 minute round where you had many small pointers that everyone could attempt to get into the round was a smart way to do it.

I generally kept a good pace here, solving 31 of the 32 puzzles and missing a 60 point Rail Pool to expect 840. Unfortunately I had a missed border on a 20 point Square Jam but 820 was still a pretty good score (3rd best in the round) with only Ken Endo and Thomas Luo finishing the round without errors.

Round 4 – 60 minutes – 600 points – My score: 610

This round had a mix of classic puzzles and hybrid mashups of those, aptly called ring of pain. There were 12 puzzles. By now I had kinda sorta began to adjust to the fact that maybe I’m more capable of finishing these rounds than I thought. It probably helped clear my mind a little bit because now I mostly just had to solve everything. Otherwise, I would have planned to avoid some of the Pentominous and Spiral Galaxies related stuff as I’m horrible at those genres.

As expected, the Pentominous and the Spiral Galaxies slowed me down but I was decent on their variants. I still managed to finish the round with a minute to spare, and I think it was largely because of the mindset of “I have to solve these”. Thankfully, unlike the Araf round, this time I had no errors. The first bonus of the WPC for me. 4 others finished the round with no errors. If I remember right, Rob Vollmert had a spectacular round here with a huge potential bonus but unfortunately had an error.

After this round I was 8th if I remember right, and sufficiently shocked at that. I’d started wondering if, maybe… but I was still quick to assure myself that it’s probably just a brief bump and it wouldn’t last.

Round 5 – 45 minutes – 450 points – My score: 420

Another Serkan round. Snake variants. 7 of them. Like Araf, I’d had sufficient practice but Snake is still such an up and down genre for me that I was bracing myself for a bad round.

I went for the Sea Serpent with about 30% conviction and managed to solve it after a few hiccups. I then went for the Persistence of Memory which I’m very confident about and it expectedly went pretty smoothly. The 100 point Easy As Snake was next and I had thankfully practiced that one because it needs your notations to be on point. I had about 12 minutes left and went for the 50 and 40 pointers and finished them with about 6 minutes to go. In a moment of false bravado I went for the 80 point Prime Snake instead of the 30 point First Seen Snake. This was the first puzzle I bifurcated in the round and it just worked, with some minor adjustments. I even had 1 minute left over to quickly check the puzzles and then 50 seconds left for a fun exercise to see how far I’d get on the 30 pointer (about 50%).

I still figured since everyone was finishing rounds, this one wasn’t that good, but it turns out my score was actually the best for the round. What’s more, many of my nearby competition scored a bit less in this round. I believe it was at this stage that I climbed to 4th or 5th and thought I was in a dream, still waiting for the bubble to burst.

Round 6 – 60 minutes – 600 points – My score: 285

My first poor round. This was a round with just 7 puzzles, but with a mixture of constraints like crossing loops, liar clues and toroidal grids being featured. There was one Slitherlink at the end that had all 3 constraints which I was too intimidated by, and probably in a more confident time post this year’s performance I would go for it, but for this year I didn’t want to. I thought I could bank on the Tapa-Like Loop to score me some good points and started with that… and broke it multiple times.

I didn’t know what to go to next, and picked the Suguru (Toroidal + Liar) since number placement is comfort food most times even if its not my favourite category. The puzzle was splendid and it helped me regain some confidence and go for the 115 point Myopia (Crossing + Liar) and it was also a brilliant puzzle that solved quite nicely. With not much time left in the round I just made sure I got 2 of the low pointers. While my score was definitely below par, it wasn’t so by as much as I thought it’d be, with others also struggling and nobody coming close to finishing the round. Ken top scored with 465.

I had lost some ground but was still 5th at the end of day 1, something quite extraordinary compared to my expectations.

Round 7 – 75 minutes – 3200 points – Team Round

The day ended with a nice team round where there were 3×3 pieces to be assigned into 9×9 grids of 8 different puzzles. We found some good logic but we messed up in eliminating one piece from Cave and pushing it to Fillomino, but we realized at the end and rectified that. We still lost a bunch of time on it, but it was a fun round nonetheless.

Round 8 – 29 minutes – 290 points – My score: 330

Day 2 began with a sprint round, having 29 small sized puzzles to be solved in 29 minutes, arranged in increasing order of difficulty. Funnily, the puzzle that probably took me longest was the first one, a Japanese Arrows where I failed to see for too long that it was forced for all the arrows to be 1. Once I got that though it set the tone for the round and there were some fun puzzles even with the small size.

I finished with 3 and a half minutes to go. This round had a special bonus of 20 points per minute saved instead of 10, but also with 29 puzzles there were more chances for errors, so I checked for 1 and something minutes before turning in my paper. I did fix one error so that paid off, and I was clean for the round. I was one of 8 solvers to finish the round without errors.

Round 9 – 75 minutes – 750 points – My score: 890

This round had puzzles that where to be solved in two different ways. For example the same Heyawake grid was presented twice but shaded cells cannot be in the same place in the 2 solutions, and this made it uniquely solvable. There were 14 puzzles (28 grids).

I finished with 16 minutes to go and checked for a while and submitted with 14 minutes to go. This meant I could leave the hall and sit outside. A new feeling. It also meant I had a LOT of points to lose with just one single error. Another very new feeling. Ken finished the round with a monstrous 27 minutes left, and was waiting outside with Ryotaro (I think, but maybe it was Thomas Luo?) when I left. Either way, they had errors I guess, because I had the 2nd highest score for the round after Ken. I was 3rd after this round but the results showed up after I’d already done Round 10 (you’ll see below) so I was pretty pessimistic while people around me were cheering.

Round 10 – 60 minutes – 600 points – My score: 125

This round had 12 puzzles with surprising twists. As can be seen by my score, I had a disaster round. I started with the Nurikabe (a puzzle with a single 50 clue and an irregular grid), and just couldn’t get it to work. Then I went to the Country Road, got the gimmick, but broke it and couldn’t figure out where. I then went to the Statue Park which had diagonally connected 5-cell shapes, and was making good progress, then broke that too. I then went to the Yajisan Kazusan which had diagonal clues and finally actually solved a puzzle. Then went to the Tapa (Alternative) which was full of letters, and broke that too. Went to the Aqre, and you guessed it, broke that as well. At this point I was done and just wanted some easy points. I went to the 30 point Sudoku and did that quickly to get some momentum going again, and then solved the Battleships (Loop). I then had 8 minutes left and spent it in a mix of getting the Overlapping Squares wrong and checking my other broken puzzles and not being able to see what to do.

Nobody finished this round but people still scored much better than I did. My score put me in the 90s for the round rank!

I think I just got in a bad rut in that round and couldn’t get out. I didn’t see anything to do but just shake it off and move on, and I tried doing just that. But my top 3 hopes were dashed in my head, I suspected a 7th or 8th is more likely and I reminded myself that would still be an all time high, so I cheered up and went into the next round as positive as I could be in the circumstances.

Round 11 – 45 minutes – 450 points – My score: 385

This round had 7 puzzles featuring some form of Knight constraint. It was latin square heavy so I was confident of doing decently but it had a Battleships (Knight Loop) which I just hadn’t had the time to figure out in practice sessions.

The round went as expected considering this, I finished the other puzzles easily, had 10 minutes for the Knight Loop, and couldn’t get it.

My score for this round was definitely below par as 10 solvers finished the round without errors. However, I probably got lucky in that the competitors closest to me (CJK, Thomas Snyder, Thomas Luo, Kota Morinishi) all had under-par rounds too.

Round 12 – 45 minutes – 450 points – My score: 410

This round had 12 Classic puzzles with an added constraint that neither shaded nor unshaded cells could have a run of 4 in a row.

This is the funniest round for me. In the moment it wasn’t funny. In the moment I was furious with myself. My brain is a funny specimen.

I started on the Mochinyoro, the last puzzle. It was 40 points, not a high pointer. I was completely stuck on it though, because I forgot the No Four In A Row constraint.

Anyway, not making any progress for 3 minutes, I shifted to the next puzzle, and seamlessly used the No Four In A Row constraint. I then went on to use the constraint again in 10 more puzzles, and came back to the Mochinyoro with a huge 10 minutes left in the round (I say huge because Ken Endo just had a bonus of 6 minutes in this round).

… And I seamlessly forgot the No Four In A Row constraint AGAIN for the Mochinyoro. And there I was, stuck, timer ticking down, wondering why this 40 point puzzle is so difficult. The painful thing is, with 40 seconds to go, I finally realized my stupidity, and solved 70% of the puzzle.

Like I said, my brain is a funny specimen.

Anyway, I didn’t suffer much because like Round 11, my main competition at this stage underperformed as well. I had the third best score in the round, with only Ken finishing without errors.

Round 13 – 75 minutes – 1000 points – My score: 590

Since this round was called Boss Rush and had just 11 puzzles for 1000 points most of us guessed it’d be either very large puzzles or very hard puzzles. Turns out it was largish hard puzzles.

I had an idea that the disastrous round 10 had pushed me down but maybe I could still have a good round here, so I went for the 130 point Rail Pool (Forgetful) right at the start. I got a lot of it logically, and then simply could not visualize a portion at the top. I tried for a long time, and just kept running into an issue. Finally (and dreading another round 10 like performance) I went to the 110 point Inverse LITSO which solved smoothly and the 110 point Checkered Fillomino with the same outcome. I then went for some of the “easier” 80 pointers, and finally went back to the 130 pointer in some mad hope with 5 minutes to go. That mad hope paid off and I finally saw the small error I’d been making, and solved it.

The round was still below par with a lot of time wasted on the 130 pointer but at least I’d got it and I’d had a good run other than that.

Many people outscored me in this round (Ken actually finished!) but again somehow not the ones who were direct competition. I had a hope I’d be 5th after discussions with some solvers and a vague idea of things.

Round 14 and 15 – Team

I’m not going to go into too much detail here, but these were 2 more fun team rounds, out of which Round 14 ended day 2 and Round 15 began day 3. Round 14 was about pairs of puzzles connected by instructionless rules that were given in the form of images with relations to each other on a separate paper. Round 15 was a tournament with 1v1 matches between individual members of teams, with some randomly drawn pots for the group stages leading into a round of 32 and the usual tournament bracket. India didn’t make it past the group stages and I feel it was largely my fault as I had an error on a Cave puzzle which made us draw 2-2 with France B.

Round 16 – Wildcard

This year the hosts came up with this lovely new idea where participants from different countries get to compete in a quick tournament of 1v1 matchups to determine the 13th place heading into the playoffs. The results had come out by now, and some people around me had made mistakes and I was 3rd. Since I was in the playoffs, Amit Sowani, as the 2nd best solver from India Team A, got an opportunity in the Wildcard tournament. He won one match and then got knocked out, the tournament led to James McGowan becoming the 13th place entrant into the playoffs.

Round 17 – Playoffs

2019 Champion Philipp Weiss won the 10th to 13th place playoff. After that, in an incredibly impressive marathon performance, Yuki Kawabe won the 7th to 10th place playoff, and then the 4th to 7th place playoff too, which meant facing Thomas Snyder in a playoff is still a nervy part of my bucket list. Then it was time for the 1st to 4th playoff. This was my first WPC playoff experience.

Of course, Ken Endo had a 1500 point lead over Thomas Luo at 2nd and a 2000 point lead over me. So Thomas was supposed to start 6-ish minutes after and I was to start 8:39 minutes after Ken, with Yuki starting just a little after me.

We got to choose from one of two sets and we chose the one with the Chained Block, Statue Park, Context and Skyscrapers (Parks) while discarding the one with Double Back, Aqre, Sigma Snake, Easy As ABC (Number). There was also to be a 5th secret puzzle, which Ken pointed out it would be difficult for the Japanese puzzlers to grasp on the spot with language barriers, and so it was revealed to be a Hidato (Knight).

When it was revealed I let out an audible “Oh no!” and then wrote it on my IB to show the people watching, with the appropriate emotion.

I then took a bit of a nap while Thomas was scribbling random stuff for the audience, knowing it’d be a while before I could start solving.

When it finally came to me, I raced on the Chained Block and broke it but thankfully spotted my error quickly and repaired to submit in decent time. The Statue Park went very smoothly, I was able to just visualize the last 4 shapes after a minor trial. The Context saw a small break in the top right which again I thankfully was able to fix without issue. The Skyscrapers (Parks) went the smoothest of all puzzles (Yuki requested to see my time later so it must have been good) and it was time for the Hidato Knight. I started quickly with a bifurcation which helped me figure out a starting path and I got going in what was a bottom to top solve. I had reached the middle and needed to tweak it which took a while. By the time I tweaked it and was mostly on the right track (I checked the solution after) and probably getting it soon, they said the time’s up and to stop solving.

Now here’s the thing: I had counted in my head the number of times the papers rubbed the surface of the table to track submissions. By my count, Ken and Thomas had finished and Yuki was on the last puzzle before I was. I didn’t know however, that Thomas had submitted and gotten back the Context 3 times with errors.

So Thomas was signaling “2” to me. I figured he was saying he’s second, and I figured I’m 4th, and I was still over the moon with 4th, because wow, its 4th! So I inquisitively pointed towards Thomas and gave him a thumbs up. Then Thomas frantically signaled “no, you are 2nd”, and I was in complete shock over that. I’d have thought Thomas was pulling a bad prank on me but they then announced it.

It turns out I reached the 5th puzzle before Thomas and Yuki and there was apparently a very small window where it looked like I could catch Ken. I was just solving and enjoying the puzzles and honestly had no idea.

So there you have it, I finished 2nd at a WPC. Unless I wake up and realize its the 14th of October and my flight to Krakow is tonight. I’m probably going to have that feeling for a while.

Thank you for reading!

Puzzle No. 521: Cross The Streams

Edit: I posted the wrong version. Apologies. Corrected now.

Yay, a big puzzle!

Rules: Shade some empty cells black to create a single group of black cells that are all connected to each other through their edges. No 2×2 cell area within the grid contains all black cells. Numbers to the left/top of the grid represent the groups of consecutive black cells which are in that row/column in order, either from left to right or from top to bottom. For example, a clue of “3” means the row or column has three consecutive black cells, and a clue of “3 1” means that the row or column has a group of three consecutive black cells followed by a single black cell, separated by at least one white cell. A question mark (?) represents a group of consecutive black cells whose size is unknown; an asterisk (*) represents any number of unknown groups of black cells, including none at all.


Penpa link:


Puzzle No. 520: Country Road

I have a lot of pending things to get to, which I hopefully do by the end of the month, including some more elaborate blog posts.

For now though, this is a puzzle.


Draw a non-intersecting loop through the centers of some cells which passes through each region exactly once. A number in a region represents how many cells in the region are visited by the loop. Orthogonally adjacent cells across a region border may not both be unused. The black cell just means it’s a hollow, I.e., not part of the grid.


Puzzle No. 517-519: Nikoli! (Tribute to Maki Kaji)

I haven’t posted in a while. There are a bunch of reasons for this, including travel and a bad reaction to my first vaccine dose.

Anyway, today’s post is a tribute to Maki Kaji, who passed away last week from cancer. I was going to elaborate on my thoughts more, but honestly this post by Thomas pretty much says exactly what I wanted to, perhaps in a better way.

I got into pretty late, and just had a year of solving before the online solving portion had to close. I do purchase their books from time to time and I absolutely love the giants series.

Like Thomas, my note of thanks will be for his broader contribution to the puzzle community via Nikoli, influencing me and so many other puzzlers positively.

As a tribute, I have written 3 Nikoli style puzzles, and by that I mean ‘Nikoli style’ – I’ve tried to keep look, difficulty and dimensions as I remember them from



  1. Place light bulbs (circles) according to the following rules.
  2. Light bulbs may be placed in any of the white squares, the number in the square shows how many light bulbs are next to it, vertically and horizontally.
  3. Each light bulb illuminates from bulb to black square or outer frame in its row and column.
  4. Every white square must be illuminated and a light bulb can not illuminate another light bulb.


  1. Place black “triangles in squares” (see 2) in the grid under the following rules.
  2. There are four kinds of black triangles you can put in the squares (shown below)
    . You cannot place black triangles in the black squares.
  3. The parts of the grid that remain white (uncovered by black triangles) always form a rectangle or a square.
  4. The numbers indicate how many black triangles are around it, vertically and horizontally.


  1. A rectangle, bordered by bold lines, is called a “room”. Fill in cells under the following rules.
  2. The numbers indicate how many painted cells there are in a room. Rooms with no number may have any number of painted cells.
  3. White cells cannot stretch across more than two rooms in a straight line.
  4. Painted cells cannot be connected horizontally or vertically. White cells must not be separated by painted cells.

Rule credits:

Penpa links




Puzzle No. 514-516: Tapa, Tapa [Palindrome], Tapa

I got a bit late when it comes to keeping my alternate day schedule so here are 3 puzzles to make up for it.

Only the last one is “fresh”. The first one is a bit silly but also probably nice, I was experimenting with an idea, some people on discord have seen it already. The second one, the variant, is from a speedsetting contest quite a while ago. We had an hour to construct a Palindrome variant. This one took me about 35 minutes if I recall correctly. The third one is just a vanilla Tapa.

Tapa Rules: Shade some empty cells to create a single connected wall. Numbers in a cell indicate the length of consecutive shaded blocks in the neighboring cells. If there is more than one number in a cell, then there must be at least one unshaded cell between the shaded cell groups. Cells with numbers cannot be shaded, and the shaded cells cannot form a 2×2 square anywhere in the grid.

Palindrome variant additional rules: There are one or more palindrome lines drawn in the grid. The pattern of shaded and unshaded squares will be the same when read from either end of a line.

Links to solve each one:

Puzzle 514

Puzzle 515

Puzzle 516

Puzzle 514:

Puzzle 515:

Puzzle 516:

Puzzle No. 513: Shakashaka

Lets start with an unrelated self-plug – Check this out!

Now to today’s puzzle. This is a “fresh” puzzle, i.e. only 2 or 3 people have seen it before.

Rules – Shade a right triangle in some empty cells, each of which occupies exactly half the cell it’s in. Each unshaded area must be rectangular in shape. A number in a cell represents how many of the (up to) four cells orthogonally adjacent to the clue contain triangles.

Penpa link to solve: (Click+drag slightly to a corner to draw in that corner’s triangle, just click for dot)

Puzzle No. 512: Kurotto

Since I’ve just been back here recently, I should note that sometimes, I won’t be posting “fresh” puzzles. Mostly this is because I also want to use the blog to organize some of these puzzles better.

I have been participating in “speedsetting” contests lately over on the CTC discord server. I’ve seen that this may seem unappealing to some more experienced puzzlemakers, but honestly, its a lot of fun. Also, mostly it allows me to put together something without overthinking about “where will it get published” and “what are the requirements”, while being in a limited time setting that makes me “feel” like I am doing something different.

What about the quality of the puzzle then? I’ll let you be the judge, with today’s puzzle, which is from a speedsetting event that took place just 6 or 7 hours ago. The constraints given were to construct a Kurotto with the only clues being in sets of 3 orthogonally connected cells, of the same shape (allowing for rotations and reflections). Basically, either a puzzle with only L trimino sets of clues or a puzzle with only I trimino sets of clues. The time given was 40 minutes but I forgot about it and joined late. Fortunately, its Kurotto, probably as comfortable for me as Tapa, so I could whip this up in 5-6 minutes. It won 2nd place!

I have more puzzles from earlier speedsetting contests that I’ll be posting in the future, but for now, here is the Kurotto!

Rules: Shade some cells so that each circled number represents the total count of shaded cells in connected groups sharing an edge with that number. Cells with circles cannot be shaded.

Link to solve on Penpa:

Puzzle No. 511: Arrow + Between 1 & 9 Sudoku

I want to call the variant a lot of people now know as “Sandwich” by what it used to be called, including in past posts on this very blog. This is a puzzle I’d worked on a while back, for a speedsetting contest that I was too late to submit to.

In other news, the WPF Sudoku Grand Prix final results are here –

There could be a minor change or two since the round 8 results are still “preliminary” but I’m confident that my final placement won’t change. So I’m 6th! Considering I started the year targeting a top 10 finish, I’m pretty happy with this. I had a really strong finish in the last 2 rounds.

What else.. oh ya, I just wanted to note that this is the vague schedule I’ll be going for (every alternate day). I’ll branch out on topics as I go I think.

Rules –

Insert a digit from 1 to 9 into each cell so that no digit repeats in any row, column, or bold region.

Additionally, the number in a circle is the sum of the digits which are covered by its arrow. Digits may repeat along arrows.

Also, the clues outside the grid are the sum of the numbers that are between the digits 1 and 9 in that row or column.

Penpa link to solve: (You can tab with surface and Sudoku, the answer check is just for correct digits)

Puzzle No. 510: Akari

So… I’m back.

I wondered what I could possibly say along with starting to post here after such a long hiatus (from here anyway).

I do plan to start posting here regularly again though. Why? I guess we may or may not find out.

So after a lot of thought on what to post as my return puzzle, I decided, I just want to keep things simple.

So here’s a vanilla Akari.


Place lights in some cells so that every cell is illuminated. Lights illuminate the cell they’re in as well as all cells seen in a straight line horizontally or vertically, not obstructed by a black cell. Lights may not illuminate each other. Clues represent the number of lights in the (up to) four cells surrounding the clue.

We have penpa links now! Why penpa over some other platforms for this blog? I’ll probably write about that in a future post. I’ll also write about someone doing some nice work to make links out of some of the older puzzles of this blog. All that and more to come. For now, link to solve:

The link is set to composite mode specialized towards solving Akari, and drawing in the bulbs correctly will trigger the answer check.