All the puzzles from our “Will Shortz’s Sudoku” teaser week can be found in this PDF.
This next week will start with a special giant puzzle on Monday, marking Prasanna’s Birthday, and then our regular difficulty trend will start on Tuesday. The specific focus is loop puzzles, with Castle Wall, Masyu, Yajilin, Balance Loop, and Round Trip all appearing.
The bonus puzzle for our high-level supporters will be a TomTom by Grant Fikes.
All the puzzles from last week’s Balance Loop/Fillomino mix can be found in this PDF.
Next week we’ll have a variety week, but with a common theme throughout all the puzzles. The exact schedule is this:
Monday: Masyu by Tom Collyer
Tuesday: Nanro by Grant Fikes
Wednesday: Tapa by Tapio Saarinen
Thursday: Cave by Thomas Snyder
Friday: Balance Loop by Prasanna Seshadri
Saturday: Statue Park by Palmer Mebane
The bonus puzzle for our high-level supporters will be a Skyscrapers by Thomas Snyder.
All the hexagonal puzzle variations from last week can be found in this PDF.
Next week will feature a combination of something old (Fillomino by Grant Fikes) and something new (Balance Loop by Prasanna Seshadri).
The bonus puzzle for our high-level supporters will be a Cave by Grant Fikes.
Earlier in 2021, Thomas Snyder and Serkan Yürekli from Grandmaster Puzzles constructed a Puzzle Grand Prix round. This week we are taking a look back at those puzzles and will be adding some extra notes on the constructions here.
You can read prior posts from my old livejournal, long before this championship, to have my opinion on playoffs. At some tournaments, like this one, the overall top solver can be clear from the individual rounds. And in the past I have been the top solver over the entire competition before the playoffs. But I’ve never been #1 after the playoffs. Rather than adjudicate the past and if there should be playoffs, I will accept the rules as they are and tell you the story of how the final ranking shaped out with a very dramatic play-offs almost fit for tv.
For these playoffs, the four competitors were in a separate room, with cameras above their desks, while everyone else could listen with commentary elsewhere. Videos are available on the official site. [I will annotate the official Finals broadcast.]
Quarterfinals and Semifinals
First was a quarterfinal with two hiccups, but that ultimately had Nikola Zivanovic in 7th advance over 8, 9, 10. The first hiccup was a Spiral Galaxies with two solutions, having eight cells chained together that are not uniquely specified. Lots of solvers turned it in but no one was accepted as correct. So the round stopped after that second puzzle, replacements were found, and it restarted. One of those replacements was a Skyscrapers Battleship puzzle with the exact same grid that had appeared in the main competition. Although no one solving in the quarterfinal remembered it, the audience knew something was wrong. After all three puzzles were completed first by Nikola, a coaches huddle followed and the other competitors agreed to accept the result despite potential of memory of the puzzle from before. Having watched all solvers, each taking 3.5-4 minutes on this grid, no one seemed to be using prior experience here. But again it is not good to have errors in the playoffs.
So the organizers held an extended break and checked the puzzles upcoming much harder before going forward. The Semifinals featured Ulrich Voigt, Kota Morinishi, my US teammate Walker Anderson, and Nikola Zivanovic. Over four puzzles, Kota and Ulrich were neck and neck through a Single Block and a Futoshiki but both got stalled by Loop Around Pentominoes. Nikola was the first to get through that third Loop puzzle and seemed like he might pull the upset in the Pinnochio Fillomino final puzzle. But there was something he wasn’t seeing and the submission was incorrect. Then Nikola’s next submission was incorrect. Ulrich recovered from the tough Pentomino Loop and Walker finished close in time too to set up another group at the end. Would Nikola finally correct his grid? Would someone else starting fresh get the answer faster? Ulrich ultimately finished first. Again, the playoffs changed nothing in the order, and #1-4 would face off, but it was quite dramatic. I was happy to have not spent the energy worrying about this round. I was working through my normal music playlist to get hyper-focused, with an added 60 minute album in the middle to deal with the delays.
We were at the main event, the Finals playoffs. 35 minutes, 5 puzzles. (Although with grading, only 31 minutes functionally.) Ken Endo would start first and then after 7 minutes, Palmer Mebane, I, and Ulrich Voigt would all start about 8 seconds apart. We started with 10 possible puzzle choices but the organizers’ checking after earlier mistakes had removed the Japanese Sums option.
Finals
[1:53:45 — start from here for video]
1:54:08 — Indeed, an impressive performance from Ken Endo throughout the championship. I had “retired” before Ken Endo appeared and change the face of WPCs. Having come back and knowing how to compete close to Ulrich and Palmer (my old nemeses) gave me comfort second was possible, Ken is something else entirely and I’d need help.
1:55:15 — Puzzle selection: So Ken Endo chose first and put Nurikabe at #1 and cancelled Double Coral (highest value and highest risk?).
1:55:40 — Palmer and I had spoken some in advance (at least to call attention to styles we wouldn’t mind appearing) and we each picked puzzles we liked and the other wouldn’t mind appearing, on the higher end of possible challenge and variance. Palmer got a Regional Fillomino at #2 …
1:56:05 — … and I got a Galaxies & Tetrominoes at #3, a style from that Round 8 Dissections where I did very well. I cancelled out Clouds, which I find too lucky than logical usually, and has been a nuisance in the past.
1:56:20 — Ulrich ended up choosing an easy mathrax and eliminated another option to put another arithmetic puzzle, wrong products, at the end.
1:57:20 — Jan Novotny, the commentator, foreshadows time advantage challenge from a Coded Nurikabe in a prior WPC playoffs for Ken. Will the regular Nurikabe be lucky this time for Ken?
1:58:59 and next 3 minutes — I had no knowledge of what was taking Ken Endo so long, but sitting and waiting this definitely seemed long. Watching later on — and I must admit I haven’t seen Ken solve very much — it seems he either tripped himself up in the lower-left with the shape of the 4, or missed core constraints that force the 9 in the lower-right. At least his solve looks a lot different from the rest of ours that will be coming and could be him getting into more intuitive than logical steps due to a bad interpretation of the left side?
2:02:00 (top middle) — Throughout the championship, I had been using a blended red/blue set of TwistErase III pencils and I put them on my instruction booklet with a V orientation (V for Victory? V for Verily since the red is down and blue is up?) while waiting out my 7 minutes. The zoom out shot shows we are just being patient as this first puzzle takes Ken awhile.
2:02:30 — A messy but ultimately correct solution by Ken is turned in after three and a half minutes.
2:03:30 — Jan mentions there are two races: “Between Ken Endo and his own mistakes” and the “race for the silver medal”. I didn’t hear this at the time, but would try my best to prove it wrong.
2:04:00 — Ken Endo gets the Regional Fillomino puzzle. Note the camera does not show the bold region shapes as well as on the paper. Ken is fairly methodical at the start to get the identity of the six digits in each region and then solves a bit. Meanwhile I’m still waiting.
2:05:57 — We all get to start the Nurikabe. The first 40 seconds you get to watch Palmer working around the grid clockwise and getting most of it right except for the 11 island.
2:07:06 — By the first focused look at my grid you’ll see I went counter-clockwise but have most of the sure bits on the paper correct and also quickly get everything but the 11 island right. I do check my count more carefully and do not turn in a wrong solution. I know there is something to fix (as does Palmer).
2:07:45 — Ulrich much more methodical here.
2:08:08 — While Ken Endo finishes his second puzzle.
2:08:20 — Palmer and I both turn in the Nurikabe about the same time; technically I solved faster by 1 second but he started with a 4 second gap so is still slightly ahead for second. With 2 minutes 20 seconds roughly in the solve, we have each carved back 1.2 minutes out of the 7 we need — provided we are right.
2:08:49 — I reform the V, because why not? I’m here for Victory or at least finishing 2nd.
2:09:13 — Fascinating that Ulrich also slows himself down at the end of the Nurikabe with an extra erasable cell in the upper-left corner. Also, his shaded cells are fascinatingly precise (i.e., they only cover 1 cell and never cross over in how they get marked). Quite the contrast from the contiguous shading I did and the very messy but fast shading Ken had done.
2:09:45 — Camera focuses on Ken and the new Galaxies and Tetrominoes puzzle while Palmer and I get the Fillomino.
2:10:10 — Palmer’s first glance mostly shows the same kind of approach Ken did, identifying the set and working slowly from the top first. When I first get the puzzle, I’m fascinated by the 4’s and the fact there are 12 regions and put these large fillominoes in immediately.
2:10:42 — Because of which region borders can be crossed, this is more limiting than it could seem and when my paper is looked at this is mostly all in as my start with a small adjustment in the lower-left. The right side isn’t guaranteed (there is a second option by scooching the two 4s up).
2:11:15 — Ken has a good (but maybe too aggressive) start to the Galaxies and Tetrominoes when we look back at him. Unlike the competition puzzle there is only one outside number clue here so most of the thinking will be about unreachable cells by galaxies as I would figure out later.
2:11:55 — Steady progress by me in the zoom out, as we go back to Ken and he has erased his Galaxies start on the left (was it all a guess?) without leaving any critical logical bits.
2:12:35 — I am finished but feel confident enough to confirm the grid to spend 5-10 seconds rather than lose time with an error. I turn in the grid before the others to get into 2nd.
2:13:00 — The spreadsheet of times in the lower-left is the only thing visible in the room to us but it lets us track the others’ progress throughout the playoffs. I am gaining confidence because, if I am correct on the Fillomino, I have gained another roughly 90 seconds back on Ken Endo and am about 4.5 minutes behind.
2:13:30 — Palmer finishes a half minute behind me (not too much room for comfort) but the gap on Ulrich before the math puzzles is good. Palmer doesn’t know it, but there was a slight error on the left side of his grid where he did not complete a valid 2 polyomino.
2:13:40 – I’ve reformed the V. Ken back near the start of Galaxies but finally noticing an important constraint which I’ll talk about soon.
2:14:07 — There are some times you are smart and some times you are lucky and in this playoff I was mostly smart but also lucky. Smart in that here (as in the Fillomino), I got a meta constraint very fast that opens the full logical path. Something Ken’s intuitive approach perhaps missed. The 5 in column two (with 6 cells as options) is a heavy constraint in the puzzle. As is the fact once you focus on fulfilling this constaint, R6C1 which cannot be reached by a galaxy readily is shaded to force the rest of the column.
2:14:24 — 25 seconds into the puzzle you get to see my grid where I have everything identified there and am simply solving to the end (admittedly I shade R8C1 too early but it is a cramped grid meaning fitting all 7 shapes is tough and the “be greedy” approach of using cells most efficiently is right most of the time). I continue to then use intuition and logic to get to a solution. R2C1 is also shaded too soon, but Galaxies is always about give and take so you’ll see I have no issue once I need to take the R4C3 cell in getting that taken back.
2:15:00 — Palmer learns of the error in the Fillomino which brings him back to Ulrich in overall time for third.
2:15:40 — You get to see a fairly empty lower-right where I’m mentally visualizing the final answer and then writing it. Another great solve (Nurikabe maybe 4 of 5 and Fillomino and G&T 5 of 5). There are now two puzzles left and things are going well.
2:16:00 — Jan Novotny on commentary calls out my lead in second and the gap closing on Ken. Just 80 seconds now with remarkable gains of three more minutes back on the puzzle style I chose! But two math puzzles to go including a super fast 6×6 one.
2:17:00 — Much to Jan’s comments, Ken does spend about a minute on the grid.
2:17:10 — I’m resigned in a 6×6 to simply writing to learn about the puzzle and not think about finding an entry point. My first digits are mostly right (just the upper-left is off and I have the middle constraints learned).
2:17:50 – And once I know how the puzzle will solve I basically am slowly writing the answer down. “Slowly” is maybe not a word I should use, as I didn’t do that poorly compared to the other two finalists here but this is the one puzzle Ken so far has been faster at.
2:18:20 — Jan is visibly excited that Wrong Products is up and has some surprises with it. No one had asked what size it would be, but going 1-20 is a slight surprise. In the sudoku championship playoffs I asked if the Sudokuro (a kakuro puzzle pretending to be a sudoku) was 1-7 like in the competition or 1-9. They didn’t answer, but the real puzzle was 1-9 and much harder.
2:19:26 — You miss my turn in but can see that I gave back 10 seconds to Ken but still have a chance on the last grid. I know Ulrich and Palmer can catch up but I’ve got a few minute lead on them both at the moment. I am starting to freak out — both at the potential to be 1st but even to just be 2nd. I have had an issue at the last puzzle in playoffs before (Beijing). I’ve had an issue with a math-heavy puzzle in playoffs before (Eger when I lost a lead on Ulrich, Belarus where I wrote an E instead of a 5 in Kakuro — long story). I don’t know yet that the Wrong Products will be a 1-20. I’m just hoping I didn’t make a silly Mathrax error and am starting to do some multiples of 7 in my head.
2:19:42 — Paper on my desk and my first reaction is to freak out. Jan correctly mentions “I wanted to see his surprise on the range of the numbers”. And younger me would have kept the bad mental image of surprise. Older me responds: it’s just a harder grid than before, which means there is a chance to make up 1.5 minutes on Ken. And while I worry others will make fun of the fact I will probably have to write all the multiples of 13 and 17 and 19 on the page, I just need to keep at it and solve smart and steady and fast enough.
2:20:50 — Yes, I have written long multiplication out for 18×19 in the right margin to confirm the product as I don’t trust my mental multiplication. At around this point I almost make a mistake which from the grid is something like 265(+/-1) = 16×18 (writing an 18 into the grid) but I double check immediately and erase the error quickly.
2:22:00 — Everyone has now gotten through 4 puzzles and there is ~3 minutes for me in front of Ulrich and Palmer although I will not know this exact time.
2:22:50 — I’m chipping away at things still (11s and then 15s) and not yet at writing multiples on the page.
2:23:30 — I’m continuing to write in the grid, with an ID for the top large sum that clears a 13 and the final crossing value for the 15. Ken is not yet writing as much in, maybe working towards a perfect factorization of all 20 numbers for one of the directions?
2:24:00 — This is exactly what is happening and the row clues look reasonable on Ken’s paper but the columns don’t have much progress on his grid. My progress is spread out.
2:24:15 — Indeed, “hard to judge who is ahead”. I’m still feeling I’m taking way too long but just grinding, grinding, grinding, not thinking of anything but the grid in front of me. The 8 I just wrote in though is in the wrong spot. Will I catch this?
2:25:30 — Ken is having more struggle at breaking out the top column clues which may mean time is coming back to me?
2:26:03 — The 8 that was wrong in my grid is now taken out.
2:26:35 — Palmer, a mathematician (but does that mean good at arithmetic?), has a lot of the top broken apart into products and some ok progress in the grid. Is it correct? A lot of the solvers have made progress in different spots.
2:26:50 — Ulrich now where Ken has been, with all the row clues broken apart seemingly (two options written on the right of the grid).
2:27:20 — I’m still the least organized in breaking apart the task, skipping from rows to columns. I’m also losing a little time in shading but keeping visually clear finished clues to help myself.
2:27:40 — But at this point I’m starting to recognize shading might be stupid? I have all the columns IDed and just start writing in numbers for what I know (the 1 and 3 in rows 4 and 5 for example). My heart jumps about 25 beats per minute. 6 entries to place.
2:28:00 — 2 numbers to place!
2:28:05 — No numbers to place!!! Is the grid full? Turn it in! Turn it in! The paper shoots to the right to the judge.
2:28:10 — My heart jumps another 25 beats. My right arm starts shaking. It will not stop shaking for another 90 minutes. But at least I only have to wait 60 seconds for my fate to be made clear. I catch up to noting the lead I had in the room entering the last puzzle…
2:29:00 — and see that Ulrich has reeled 3 minutes back and turned in. This could be bad if I made an error (as in Beijing) and he is correct before I can do a 5 second fix…
2:29:08 — But it is not bad. I have won. The V is formed one last time, without color coordination, on my booklet as my proctor tells me I am correct. I have somehow had the best third day in a WPC in my memory. I did the 2 improbable things (finish Rd 13 super fast to jump into the finals, and finish the playoffs super fast to make up > 7 minutes). And luck fell my way on the rest — the right puzzle selection, some unexpected mistakes by others….
2:33:00 — I wait out the clock as no one else finishes the wrong products.
2:33:20 — Jan: “I think he wanted this a lot”. And I really did from 2008 on after coming so close in Rio de Janeiro with the top spot becoming a 2nd after playoffs. After 2011, I would go to steps like not competing in the WSC (as reigning champion) to maintain focus for the WPC. 2012 and 2013 were both crushing defeats in different ways for me. Leading to a TIME interviewer even writing, after discussing how my focus on science may be affecting my puzzling:
“There are those who think the distraction of attempting to solve the world’s immunological woes is why Snyder is the puzzling world’s Ahab: for all his success, he has never won the individual world championship. It’s something of an obsession.”
And there is no way to deny the obsession part fully, when the history of my live blogs is out there, even if the passage of time, broader perspective, and family loss made the goal diminished entering Prague. I had partly moved on with my life after 2013, to medical pursuits, and had stopped hoping in the last few years it would be possible, had even stopped competing. This year’s win was completely unexpected. Amazing that the city of Prague, where I won the first title as mom watched from home, would be the site of this ultimate success in the first year I no longer had her cheering from afar.
I take a shower and walk outside to try to slow my heart rate and get my hand in a state I can write with it again because there are team playoffs to come. I wonder for awhile whether my attaining great mental focus over short bursts like I did earlier in the day could lead to neurologic injury. My hand finally stops shaking.
Eventually the team finals begin and there you can watch the video and I won’t write too much — the individual parts were hard and I stuck more to logic than intuition on Easy as ABCDE. Once Walker joined to help we moved much faster to complete the real assignment, I finished my grid and we tag-teamed on the other. We still made some slowing errors like not copying all the blackened cells into the second grid. We get to the team table where Wei-Hwa and Palmer have a good path close to the answer, and work for a few minutes to complete but Germany beats us by under a minute. Perhaps time I could have gotten back by a better individual solve but who knows? Japan has made a larger error which they don’t know at the time (they brought the wrong team sheet up to the main desk) and fall all the way to last when Hungary finally clears the Easy as ABCDE desk. The error in papers leads to a larger (but maybe overblown?) controversy about how team captains have been interacting in the room, generally looking at the individual desk papers as Germany and US wait 15 minutes for third place to finish.
Closing thoughts
Except for one non-unique puzzle I ran into in the main competition, something unusual in the connectivity of the loop in the last team round, and then a set of issues in the quarterfinals of the playoffs, this WPC was rather clean. The round structure (while long) had a nice split by genres and let different skill sets come into play without as much “pick your favorites” as other tournaments that mix them more together. I didn’t like all the puzzles — some still seem to need more guessing than I’d want — but there were some very stellar themed puzzles too as expected at the end. While Ken Endo and Japan had back luck in the playoffs, it meant I got a little karmic payback. I would have 4/1 WSC/WPC titles with individual ranks used. I have 3/1 WSC/WPC titles with playoffs used now. And I’m now the first person to hold both titles, at least until Kota Morinishi catches up in WPC or Ken Endo gets even better at Sudoku (already nipping me at 9th > 10th this year).
This is a very weird report to write in a very tough year in my life, that has matched low lows with this unexpectedly high high. I’m still thinking through what I’m doing with my life now that my mother has passed. That consumes a lot of time, and pushes me to work harder at Verily. In the midst of those emotions I was not ready before or after Prague for this victory. And I still struggle with the fact time away from science is not leading to cures, but time on puzzles brings joy to many in different ways. If Rounds 1-3 had me thinking of quitting puzzles altogether, the overall event and the time with friends in puzzles reaffirms that I need to keep the complex balance of both science and logic to feel whole in my life.
Thank you mom for pushing me to try hard in all the things I do, for teaching me math and multiplication, and for introducing me to puzzles. You weren’t able to see this victory, but I hope you know that I owe a lot of my success to you and dad and I miss you every day.
In short, I did not have any real expectations for Prague and the WSC/WPC.
If I had goals, they matched my 10:6:3:1 statement from 2017. I was hoping for 10th at the WSC (6th place team) and 3rd on the WPC (1st place team). The better shot at the WPC tied to there being more of an experience factor across the dozens of puzzle genres at a WPC where competition rust means I will probably not be competitive at just sudoku at a WSC again. In Bangalore, I finished 10th in both events, so behind that goal for the WPC. In Prague, at the WSC, which precedes the WPC, I again finished 10th. With a day off for tourism, and having worked through the instruction booklet and many of Palmer Mebane’s practice puzzles for the US team, I was ready for anything as the WPC started, planning mostly to do my best. The organizers had structured rounds somewhat in the same way I structure genres on GMPuzzles, and I felt more comfortable than usual that I could find flow in most of these rounds.
Note: One change that I’ve done over the last two years is to focus on what I am doing in each round, but to completely ignore the scoreboard and not get caught up in the emotion and horserace of the championship. That was true this year as well, so in the summary that follows, until Day 3 morning, I don’t actually know any of the other competitors’ scores or how well I am doing except from gut intuition. There were many great competitors at the event, but I will mostly focus on the eventual top 4.
Day 1 morning
One challenge of not “competing at puzzles” for awhile is that you lose some of the skills that are required in competition at the highest levels. These skills aren’t about how well you solve different puzzle styles logically — I’m still testing those skills regularly as I edit for GMPuzzles — but how you solve different puzzle styles fastest. Pencil and eraser and trail-and-error is the right approach sometimes, or after getting some things for sure by logic.
While I know this from experience, each year — not having learned the puzzle designers’ style — picking the balance of logic and “intuition” let alone the right way to view high point puzzles challenge-wise takes some adjustment. I stumbled out of the gate. In Round 1 (Shading), a genre that often rewards intuition, I quickly got through the Shakashaka (the first in a set of first puzzles in rounds on a grid shaped like the Czech Republic) but then ran into harder logic than expected on the Heyawake. I grinded to a solution, but needed lots of tweaks (and later when the round was graded, was shown I had not actually gotten it right). I jumped forward to the hard Cave which was easy by logic and then got to the hardest puzzle of the round, the 100-point Coral. Here I did a little on the right by logic and then lots of intuition in the middle. I had the wrong logic at the start and my guessing never worked. Long after the round, I still have not found a fully logical path to solve this puzzle, but regardless the time spent on 100 points not earned in Coral and 80 thrown back in Heyawake was a high cost, considering 5 other puzzles I never looked at. 275 after 45 minutes.
Round 2 (Objects) should have been a strength. Indeed, with a lot of easy value puzzles it was really just solid logic through all of the 40 minutes. I finished the round, but I somehow managed to not write one last crossing word into the only high value puzzle the Scrabble, throwing away 85 points I should have had. It seems this was a common error as other top solvers including Ken Endo were at 345 like me and not 430+.
After two bad rounds, Round 3 (Skyscrapers) was my lowest of the championship. Palmer Mebane had written a full practice round in advance, meant to introduce all the new styles, but there were a few too many new rules and/or I was a little impatient on small 5×5 grids to use intuition over logic. This was a bad strategy and I had two answers that were marked wrong, and a lot of unlooked at puzzles. Getting 265 on a round where some were saying finished (and would be around 600+ points) was far from how I should be solving.
In short, the morning of Day 1 was one of the worst possible starts to the tournament I could have felt. I was wondering at lunch why I was here, why I was still trying to compete and not do more important things. Why don’t I wind down GMPuzzles or hand it over to other people to run. I’m wasting time trying to keep up with puzzles when I have other things I should be doing in my life. I took a long walk and played some Hollow Knight after lunch to clear my mind. Again, I wasn’t looking at scores but I knew I was mostly playing to do my best for the rest of the day and take it from there. With much longer rounds to come (60, 90, and 90 minutes) in the afternoon, there was still a lot of puzzling to do.
After Day 1 morning: Score (rank)
Ken Endo 1560 (1st)
Ulrich Voigt 1360 (3rd)
Palmer Mebane 1245 (4th)
Thomas Snyder 885 (24th)
Day 1 afternoon
Clearing the mind helped, or at least it seemed to. I felt I did fairly well (closer to 10 points per minute) in the Polygons (read: irregular geometry) round back from the break. I skipped the Slovak Sums and a few other puzzles, but had a good logical flow through the combos and slitherlinks and six winds. Got very lucky on the Boomerangs with a right guess in the first 15 seconds (I was not intending to spend too much time on it). Closed out by actually solving some of the (Hexa) skyscrapers which made me feel better after the bad round 3. Only “Coral” would still be on my mind as a possible kryptonite from the Czech constructors. While a better round, I continued my errors in round streak with a repeated digit in the Kropki part of the pyramid combo.
Round 5 at 90 minutes focused on Variations and Round 6 at another 90 minutes focused on Combinations. The subtle difference is that a “Variation” is a new riff on an existing style that usually introduces just one or a few rules while a “Combination” is blending at least two existing styles’ rule sets as is. Due to constructing a lot of puzzles, I expected a lot more comfort in Combinations and shifting between two styles of thinking but even the Variations weren’t too unusual. Nicely, many of the styles had 2 or 3 puzzles so you could get into them. My strategy for Round 5 was to avoid the high value multiplication puzzle (math-heavy puzzles are not my strength) and also some of the dominoes but get the rest. And this is exactly what I did, although I still left points on the table with errors with 25 + 70 points lost on the Fillomino with given numbers and the reduced domino with sums. Overall nice puzzles, just wish I was solving them more cleanly without mistakes but the 705 would be an ok score.
Round 6 was the closest to the point average I would be since round 2 as I also finished all the grids. While I started the round and ended the round (and apparently never got a correct answer) on the Nurikabe Tapa, which lacked a clear deducible path to the solution, I completed everything else. The Snail End View Untouchable had an incredibly high point value but determination and solid logic got me through it. Indeed, for most of the afternoon I was trying to be more patient and just think through answers, except towards the very end of some puzzles, and the points played out this way. I wouldn’t know it until later, but my afternoon was second only to Ken Endo’s as a session and I had recovered from the 24th place start to 5th.
Day 1 PM -> Day 1 total (D1PM Rank; Day 1 Rank)
Ken Endo +2490 -> 4050 (1st; 1st)
Ulrich Voigt +1985 -> 3330 (5th; 2nd)
Palmer Mebane +2030 -> 3275 (3rd; 3rd)
Thomas Snyder +2110 -> 2995 (2nd; 5th)
Day 2 morning
Day 2 brought another set of comfortable puzzle genres, and more rounds with the first puzzle on a grid of the Czech Republic. Round 7 (Paths) had more low point puzzles than high point puzzles so after getting through the two largest ones I distributed my time amongst all the rest except for the Country Road which I never had a chance to look at. The 480 points in 45 minutes was my highest ratio to that point, although for 7 straight rounds I had a broken puzzle with the smaller every third turn loop.
While I had talked about sticking with logic as much as possible, Round 8 (Dissections) was going to force me straight into some intuitive solves again which I welcomed as a challenge. Indeed some things can be done by logic, but in many of these styles like Pentominous a little bit of trial and error helps to visualize the contradictions and get to the answers. I solved from the back to the front, starting by being surprised by the ease of the Burokku at 100 points, but skipping the “codded dissection”. After Slash Pack I jumped to the big pentominoes start, assumed the solution needed to be greedy, and basically wrote it down except for one small tweak of one of the two Y pentominoes to fulfill the unusual 2×2 rule. Going forward from there I had 12 minutes left with just the codded dissection, and got it out with a little under 6 minutes on the clock. I checked that all grids were complete, but then turned in as soon as possible for 5 minutes of bonus. I could have checked — all my earlier rounds had had small mistakes — but nothing was obvious to check and find across all the puzzles. It would not be until later that evening that I learned I was clean and earned some bonus. Finally!
Last of the morning was the Numbers round, and I am generally weaker at math-heavy puzzles. But a few of these were more number placement than heavy arithmetic. Doubleblock would join Coral as a style that I did not want to see from these constructors, but there were some phenomenal TomTom (Jiří Hrdina’s puzzles being some of my favorites from the day). One challenge in general at WPCs is that by creating certain puzzles and writing certain rules, teams have a chance to guess secret constraints about the grids. In this case, a few teams had figured out, given the very unusual rules for Star, that there was exactly one possible answer given a likely assumption that all given numbers formed a consecutive set. Besides that one negative (from a competition fairness standpoint), and my own time fiddling with the Antimagic Square by guessing but not hitting the solution, I did adequately in the round.
Again, not looking at scores until Day 3 morning, I felt I had done ok but had no confidence what that meant (8th? 5th?). Turns out I had another stretch as the 2nd best solver for the half-day session. Ken Endo, who would be the best in each of these sessions, was again first.
Day 2 AM -> Thru Rd 9 total (D2AM Rank; Rd9 Rank)
Ken Endo +1785 -> 5835 (1st; 1st)
Palmer Mebane +1605 -> 4880 (3rd; 2nd)
Ulrich Voigt +1380 -> 4710 (7th; 3rd)
Thomas Snyder +1640 -> 4635 (2nd; 4th)
Day 2 afternoon
A very long competition was continuing with a few more novelty rounds and then the first team rounds. Round 10 (Double Trouble) focused on standard styles with a doubling of the rules. One thing I have critiqued at WPCs is that there are so many rules. This year’s instruction booklet had 83 pages. And the rules are so often written by authors with new words as opposed to common, consistent definitions with just the new parts called out like “Standard [genre] rules; also, [the one new thing]”. So it takes a lot of time to just read things I should already know and sometimes within that I’ll miss the few words which are different. Long story short, at some point in every WPC I will be solving something without knowing the rules and therefore miss the puzzle. This year it was the Double Shikaku with a constraint of clues in dominoes being split (in other puzzles it was often any numbers can be in any of the grids). So I got to an “answer” for 90 points that wouldn’t prove right as I wasn’t solving their puzzle. I also struggled with another of the Doubleblocks but got everything else.
Round 11 (Regional) played with sub-area shape variations on top of standard styles. I mostly got the points I expected except for a couple where I encountered errors while solving and didn’t think I could tweak. Round 12 (Innovative) was similar, although I hit the first non-unique puzzle in the competition which gave me some concern. These were shorter rounds and I only felt I did ok, but I was more consistently around 9-10 points per minute. I still had some errors, including another repeated digit written right at the end of Mirror Labyrinth. But if my morning of Day 1 was a low point, I felt I’d recovered so that the playoffs and a strong US team result were possible.
Two team rounds followed, both hit by having a task the whole team was working on at the same time and trying not to bump elbows. Both had fairly high challenge but we got through both, one time a little ahead of Japan, our main expected rival, and one time several more minutes behind. Notation was a huge challenge for us on that round, and we had to erase and restart a few hexes of that Coral/Easy as ABC variation.
Day 2 PM -> Thru Rd 12 total (D2PM Rank; Rd12 Rank)
Ken Endo +1775 -> 7610 (1st; 1st)
Palmer Mebane +1160 -> 6040 (12th; 2nd)
Ulrich Voigt +1305 -> 6015 (4th; 3rd)
Thomas Snyder +1180 -> 5815 (10th; 4th)
Day 3 morning
Having not read the scores throughout the tournament — maybe even thinking I was out of the podium running after the Day 1 morning — I was filled with energy to see the scores on the morning of the 3rd day. I was in 4th, and had had many rounds where I was outperforming Ulrich and Palmer so was capable of having a good result.
But here is where the competition structure gave me a small challenge. There were three rounds to the playoffs in this event: Players 7-10 would compete with puzzle selection and time bonus favoring the better ranked players. One person would advance to join Players 4-6 in a semifinal. That playoff would set up the finals with 1-3 and the winner of the semifinal. I was starting the day just ahead of others for the top semifinal spot; Nikola Zivanovic was 5 points behind with 5810 and Kota Morinishi at 5790 before Bram de Laat at 5510. I felt comfortable I wouldn’t fall out of the semifinals, so I started to think about how to skip them entirely. At 7 AM in the morning I’m starting to visualize how I want the day to go, to get to what I thought was a 5% chance of winning the playoffs.
The very first thing, in the last 90 minute round of the individual competition, was that I needed to solve my brain out and also hope for an error or poor round by one of Palmer and Ulrich to make up 200-225 points. Specifically, I figured this meant finishing at least 12 but more likely 15 minutes early, something I wasn’t that close to all tournament except in Round 8. If I could do that I could maybe get a straight path to the finals, I’d probably be close in time to everyone else there except for Ken Endo. Then, solving my brain out one more time and hoping for some Ken Endo mistakes was the path. Only two of these four things were in my control, and after breakfast and a good morning playlist to get mentally ready, I got started on Round 13.
Moreso than in past tournaments, I did a lot of gameplanning for how to go through rounds. Here I decided on a lot of preprogrammed jumps. I started in the “Wrong” section where all digits were +/- 1, but solving backwards so I could end on the Doubleblock. I then jumped into the coded section starting with the other Doubleblock, then solving forwards through the Coded and Liars sections before solving the easier missing clue starting puzzles. I had time targets for each of these runs, another thing I’m not used to doing. With 180 points for the “Wrong” section I was hoping to see at least 72 minutes on the clock. I actually saw 76! The Doubleblock was the only thing that slowed me some but it was the hardest of the 4. I didn’t make its first move logically — I used a forcing deduction that proved false — but that gave me everything I needed to solve it. Getting to the coded doubleblock I then wasted 2 minutes solving it like is was a 1-4 puzzle, not 1-5, at least in interpreting some of the sums. Probably lost some time there, but saw the Aha from constructing very constrained skyscrapers before in the next puzzle to make back some time. The coded Coral went fine, and then I hit what was a huge potential concern: The Coded Arrow.
One thing about competing at the WPC for so long is that I have a very good sense of puzzles I am good at and others I am not as good at. ~10 years ago some of my negative posts might have been complaining about F*ing arrow puzzles. I’ve taken time to get better at the regular form here, but when you use coded clues or +/-1 clues, it can get much harder. One lucky break I caught was that this year the new Toketa puzzle volume 6 had a section called the “Truth About Arrows” which included some new construction rules including an Octagon rule. I hadn’t bought these before, but decided to buy all 6 volumes in Prague and had read, based on a pointer from Walker, the Arrows section the night before. That Octagon rule proved quite helpful. Having found the 0 and 1 letter clues by logic, I could then identify that 2C + D = A + B + C + F from the octagon rule. With only 2,3,4,5,6 leftover, I could identify C and D as being 4 and 6 in some order and the grid made F = 2 very easy. The 95 point puzzle probably took 40 points worth of time. My time check for here, with 380 points more solved, was 34 minutes left on the clock. I had 44! The Liar puzzles went a little more at normal not accelerated pace, at least the Liar diagonal slitherlink where I was concerned that I might violate the diagonal cells lying constraint which was not too clear in the written rules. But I got through those and then cleaned up the 85 points of puzzles at the very start and had ~12:30 left on the clock. I turned as quickly as I could through the booklet to confirm that I had solved all of the 17 puzzles and turned in without checking any individual puzzle any more. My visualization of the morning needed a lot of time bonus and I was going to get every point because it could count.
Afterwards, Palmer mentioned maybe getting lucky towards the end and finishing one of the Doubleblocks which probably kept him in 2nd, but Ulrich had not done the Coded Arrows. 12 minutes + 95 points would be 215 gap (I needed to make up 200). I just needed to be clean. We had a team round in here then while waiting for the scores, where we split up the task and solved fairly well as a team but had a non-unique loop in the grid we never fully understood.
For the first time that day I had an anxious wait to see if my crazy fast and focused solving had worked. At lunch, not expecting the results up yet, Ken Anderson told me something about 7 minutes and being in the finals. I rushed upstairs to get the context. I had achieved magical goal 1 in my visualized path to a title. And the results were indeed super close. While Ken Endo continued to be well above the rest, 2-4 were within 35 points and I had snuck into 3rd. Ulrich had a time advantage and first puzzle choice in the semifinals but he would be the one to have to do extra solving.
Rd 13 –> Final (Rd 13 Rank; Final Rank)
Ken Endo +1030 -> 8640 (1st; 1st)
Palmer Mebane +725 -> 6765 (6th; 2nd)
Thomas Snyder +930 -> 6745 (2nd; 3rd)
Ulrich Voigt +715 -> 6730 (7th; 4th)
Continues here: Playoffs
I hope you enjoyed the first week with Grant Fikes contributing puzzles. Grant will be a regular author in the future, and has already sent in a lot of outstanding puzzles for The Art of Puzzles. While his best puzzles and his largest puzzles (sometimes one and the same) will be saved for that publication, a lot of fine leftovers will still end up here on a weekly basis. In other words, if you’ve enjoyed what you’ve seen here you’ll be amazed by what is in the book. Still, if you’d like to see some “Giants” from Grant, please check out the three he released last weekend 600 (LITS/”Tetra Firma”), 601 (Shakashaka/”Proof of Quilt”), and 602 (Norinori/”Dominnocuous”).
Who will our next Contributing Puzzlemaster be and when will his or her puzzles first appear? Only time will tell. For now I wanted to announce that the weekly release schedule will be going through a few changes. Since I have been publishing Sudoku and puzzles in five other genres (object placement, number placement, loops, shading, and region division), for most weeks going forward there will now be one puzzle in each of those six areas. Every other week will have a change in types (for example Masyu this week, Slitherlink the next) so there will be some balance in what gets posted. Over time, the genres will cycle through each day of the week so that easier and harder puzzles of all styles appear. That’s the basic plan, but there may be a few other surprises in store.
Finally, since a small number have been asking for more hints on the hidden contest (which remains undiscovered), and since I’ve not been responding privately for the sake of fairness, now seems a good time to narrow the hunt somewhat. While there have been a lot of posts here, from Doctor’s Notes to solving tutorials, this site is primarily about the puzzles. Somewhere in those 60 posts is what you need to find the “+1 puzzle” and possibly win a free book.
Regards, Dr. S.
PS: There will be no “Ask Dr. Sudoku” this week, but if you have any questions you would like answered in a future column, or past puzzles that have appeared here that were not covered that you would like some more insights on, this is the time to inquire. Going forward, I intend the “Asking” to be more active and cover just about anything (from puzzle that use baskets to NCAA tournament brackets). Solving/construction tutorials are interesting, but are not meant to be the only kind of topic.