Some solving steps for Puzzle 499, a bit about LMI, and some other stuff

I am attaching a mini-walkthrough PDF for the Arrow Sudoku I posted for the league recently. Its a bit rushed, and only takes the solve through the more difficult deductions, but should be really helpful if you were stuck on that Arrow Sudoku or didn’t attempt it but want to know more about the variant in general. Here’s the PDF –


Now, a bit of a plug. Want more walkthroughs? We do much more detailed ones for LMI patrons. Also, I should say that, at least currently, supporting LMI would mean you are supporting my personal goals too (which is why I don’t have any such effort for this blog).

Also, I might have to disappoint any fans of milestone puzzles by saying that I currently don’t have anything planned. But you never know right? Maybe I think of something worthwhile in the next few days. If I don’t, then come Saturday I’ll just post a League Sudoku as my 500th and that’ll be that.

Soon I’ll be shifting residence, so I’m generally a bit more busy since I want to finish a bunch of things before I probably lose internet access for a week or two.


Puzzle No. 499 – Arrow Sudoku [Daily League]

This puzzle has a nice application of group-thinking… I think. The solving path is also pretty narrow. Not something I’d advise for beginners.

Remember that you can solve the puzzles from the League online on the Sudokucup Guest League page with a 24h delay.

Rules – Follow regular Sudoku rules. Additionally, the number in a circle is the sum of the digits which are covered by its arrow. For circles with multiple arrows, apply the rule for each arrow separately.

Rated – Hard.




WSC/WPC 2014 Recaps: Part VII – WPC Day 3, Prizes

On Day 3, we had the individual round results displayed. I finished 23rd, which was an improvement on last year’s 24th by a single rank. At this point I remembered that there was a special prize for 22nd place at the 22nd World Puzzle Championship last year in Beijing. I wondered if that had become an annual thing and made a mental note to ask Alan. I hoped that no one would knock me down to last year’s rank. A small part of me also hoped I wouldn’t climb so I could claim that 23rd place prize if it existed, since there aren’t any big differences between 22 and 23.

Anyway, up next was a single team round, before the top 10 competed in the individual playoffs. This was a unique team round, with three phases and the third phase being a team playoff of sorts. The round was built around a puzzle which required formation of squares using some constraints moving counters and using knight moves from chess. It was a fun, easy round, but the first 7 puzzles were only the first part, or the first two phases. The third phase was for the top 8 scorers of the first two phases.

Round 15 – Square Bashing (TEAM) (Part I) (30 minutes) – 2040/1800. 7/7 solved.

Rohan is great at chess, and I’m good with moving pieces, so we complemented each other well, and with assistance from the other two team-mates we finished the 7 puzzles in good time. Not good enough to be top 8, but a solid enough finish to the WPC for Team India. The biggest reason this was a perfect team round though, is obviously the fact that my team didn’t have to deal with my handwriting for once.

The team finished 15th. Considering we missed the 2014 Indian Puzzle Champion, Amit Sowani, this was a good enough result. Jayant Ameta was a debutant and got some welcome experience. Hopefully he improves in the coming years so we have more depth in the team.

Anyway, the next part is purely from a spectator’s point of view… for the most part, anyway.

Round 15 – Square Bashing (TEAM) (Part II) (45 minutes) (2800 points for first finisher)

This round was more physical than other rounds. Teams running and jumping around on boards is probably not what you’d expect to see at a World Puzzle Championship so this was fun. Basically, the humans were the movable counters and the floor was the grid. All 4 team members stood on different starting points and there were numerous rounds of forming a square, reaching another starting point, and forming another square. The rules were quite strict and any wrong step that is submitted to the real-time judging personnel would result in a disqualification. Unfortunately, this is what happened to Team Japan, who ended up with 0 points. Otherwise, as far as I can remember, all other teams managed to finish the round fine, though I don’t remember rankings and scores.

After the round was officially done, some of the spectators, myself included, decided to try the puzzle out ourselves in seemingly random groups of four. Our huge advantage was that we’d seen that one of the squares formed took up all four corners of the grid, and another took up just a 2×2 area of cells. Even so, since we were playing for fun, we put that away. For some reason I played twice, I guess because there was a group with just 3 people in it and needed a volunteer to play it once.

WPC Playoffs –

Unlike the WSC playoffs, I attended these. Japan had three solvers in the top 10, and Germany were close to having three as well, but Roland Voigt just missed out with an 11th place. The playoffs were divided into three parts. The first part was between solvers ranked 7-10. Here, Kota raced ahead even though he started after 2 players, coming into it at 9th and ending up 7th. He advanced to the next part, which would be between the solvers ranked 4-7. Here, Palmer Mebane started ahead of the other three and finished ahead of the other three, to reach the final stage.

The final stage had Ulrich Voigt (Germany) starting around 2 and a half minutes before Endo Ken (Japan), 3 minutes before Florian Kirch (Germany) and 4 and something minutes before Palmer Mebane. In the second puzzle itself, Endo hit a roadblock and just couldn’t make things work, allowing both Florian and Palmer to jump ahead. He kinda sorta recovered and was catching up until the 5th puzzle (or maybe the 4th, there’s no list on the Instruction booklet so I can’t be sure) where he hit a roadblock again which took him out of the running altogether. Ulrich and Florian were both moving along steadily (or, well, blitzing through at unbelievable pace, but steadily by their standards I guess), but Palmer was having a great time of it here. He had two amazing solves in there, including (and my memory is foggy here on the details) an Unequal Length Maze in 20 or so seconds. At the end, Ulrich managed to hold fort, but Palmer finished 22 seconds after Ulrich, a much lesser margin than the staggered start of 4 minutes would indicate. But Ulrich is, deservedly, the 2014 World Puzzle Champion, making it 3 in a row. Ulrich is a 10 time World Puzzle Champion with this victory, but this was the first time he has a series of 3 in a row, so he’s stronger than ever right now. Florian finished at 3rd, holding steady with the rank he started the playoffs at. Endo had a bit of a fall, but thankfully due to the categorized playoffs, he still has an impressive 4th place to show for it. Congratulations once again to all the winners.

So that ended the WPC, and after that we had the traditional game of football. This time, I didn’t break anything! I also literally let out a celebratory yell right after the game stating that I didn’t break anything! This is a big deal after last year. I think. Anyway…

That night we had the closing ceremony. Here’s the big official list of award winners. I was obviously waiting for my nice little unofficial award. I had, by then, talked to Alan O’Donnell, one of the lead organizers, about the existence of the award for Xth place at the Xth WPC. Turns out that this award was around this year too, and since this is the only year where I could improve my ranking (23rd from 24th) and still win this award, I’m happy to get it. From the next year I can target better ranks in peace. This was all part of the plan… is what I’ll claim from now. Anyway, here’s the Mayor of Croydon presenting the medal –


Incidentally, she is originally from India and settled in the UK. She requested to meet the Indian team as well. After a pleasant conversation, we had a photo taken.


After the ceremony and dinner, we had the usual Karaoke night. Other than the fact that the World Sudoku Champion Kota Morinishi (Japan) gave a great solo performance AND stuck around for a duet with David Jones of Canada (how epic would a Champion duet have been? Should’ve asked Ulrich to stay on), we did manage to uphold the tradition we started last year of multiple countries’ participants getting together for Wonderwall…


As always, I stayed up until my departure time and slept on the way to the airport and also while waiting for the flight. So that’s it for the recaps.

Just to summarize India’s rankings (only the A teams),

World Sudoku Championship –

India A – 6th (New Indian record for best team performance).

Individuals –

Rohan Rao – 14th. Myself – 21st. Rishi Puri – 36th. Sumit Bothra – 55th.

World Puzzle Championship –

India A – 15th.

Individuals –

Myself – 23rd (New Indian record for best individual performance). Rohan Rao – 36th. Swaroop Guggilam – 48th. Jayant Ameta – 90th.

To end these recaps officially, here’s the full Indian team. The front row: myself, Deb Mohanty (WSC team captain), Kunal Verma (WSC B team), Jaipal Reddy (WSC & WPC B team). The back row: Jayant Ameta (Also WSC B team in addition to WPC A team mentioned above), Rohan Rao (WPC team captain), Rishi Puri, Swaroop Guggilam (WSC B as well) and Sumit Bothra.


WSC/WPC 2014 Recaps: Part VI – WPC Day 2

Day 2 had the rounds with innovative and new puzzles and some rounds with real scoring potential.

Round 8 – English Country Garden (60 minutes) 690/900. 10/12 solved.

This was a round featuring some new styles and some clever representations of old ones, all falling within a theme of objects/animals/etc. found in an English Country Garden. This round featured some big strengths and some bad weaknesses. I don’t know why Cobwebs need to be featured from a garden (edit: I realize they are part of gardens, I just think only the good stuff about gardens should be featured. Or maybe I’m just incredibly biased because I don’t like cobwebby puzzles 😛 Moving on…), but I am really bad at those so I left them for the end and couldn’t get either done. Unfortunately both were high pointers so my score took a hit, even though I started really well with Flowerbeds and Vegetable Plots (Garden!).

Round 9 – Loop The Loop (60 minutes) 670/900. 8/11 solved.

Obviously this was a round full of loop puzzles, both new and known. Overall it was a good mix. Considering I’m good at Loop puzzles this round didn’t go too well. Made a few mistakes, including the Ripple Loop where I spotted the mistake just as they called for time, meaning there was a horrible minute where I was staring at the mistake and couldn’t do anything about it. Ouch.

Round 10 – The 200 Club (90 minutes) 1200/2000. 6/10 solved.

This was my only problem with Day 2 – I don’t like the concept of organizing a round where all puzzles have the same value. I won’t even say the organizers didn’t achieve this as per my experience, because honestly its quite impossible to achieve 10 puzzles of the exact same difficulty. One example where the difficulties definitely did not match for me personally was with the Non Consecutive Kakuro, which had a difficult Global step while the LITS variant was mainly a local solve. Also, a puzzle like Yajilin or LITS variant is much easier to bifurcate and retrace on than something like a 3-in-1 puzzle with multiple constraints. All in all, I just think this could’ve been a perfect round without the same-points theme, and instead just calling it a round with 10 really tough puzzles.

Having said all that, the puzzles were really fun, and the round will be remembered for some of the well built logical steps, and not for the scoring, so the overall experience was still pretty good. Personally, I didn’t do well here because I finished the 6 puzzles I got right within something like 55-60 minutes, and kept breaking puzzles for the next 30-35 minutes. That’s the most frustrating thing to happen with really difficult puzzles, but that’s my own stupidity.

At least it wasn’t as frustrating as something my Swiss friend Fred Stalder did – solving the entire Non-Consecutive Kakuro and then finding out that you’ve switched a 14 sum row and a 20 sum row in an otherwise correct puzzle has got to sting.

Round 11 – Not Quite Classics (60 minutes) 1000/1200. 13/16 solved.

This round contained more extremes than Round 8 in terms of strengths and weaknesses. 5 Tapa variants and a LITS+ meant I pretty much had 6 high-value puzzles (a total of 550 points) in the bag in around 15 minutes. I only wish I wasn’t equally bad at other puzzles as I am good at these. I still think I could’ve done better here since I broke both Diagonal Numberlinks before fixing them. I always get scared of Cross Math puzzles, so I didn’t look at either of them and instead tried and failed to finish a 100 point Tetromino Sums at the end. Maybe I should work on facing my fears.

Round 12 – Something Different (60 minutes) 760/1200. 10/15 solved.

Probably the worst round of the day. This round had one strength (Mini Coral) and everything else was a weakness. I wasn’t expecting much from it, but even so, I would’ve liked to avoid breaking puzzles. Also, I completely forgot about the 140 point Flip Mirror Sums which I feel I could surely have done in the time I spent struggling on each of the two Chaos puzzles. Ah well. At this point all hopes of a top 20 had vanished unless I scored a substantial bonus in Round 13…

Round 13 – Afternoon Tea (45 minutes) 590/670. 7/8 solved.

… and I almost scored a substantial bonus in Round 13. This was a nice round themed around the “T” shape, and all puzzles featured usage of the T-shape in some way. There were two Tapa variants here too which saved a lot of time, giving me 210 points in about 5 minutes. Unfortunately, I don’t know how to spell when the timer is running, as we’ve established from Round 1 in the previous recap. I hit the T for Trees puzzle, which was a mix of Scrabble and the T shape constraint, and in the word list, one of the words was Macadamia. That’s MacadAmia. With an A. I’m emphasizing this, because I entered an E into the grid instead. Now this might not be a big error, and according to Roland Voigt, Will Blatt seems to have received points for misspelled words. However, it just so happens (typically) that this was a crucial letter to mess up. The word Papaya was supposed to connect here with the A. Since it was an E, I had no place for the Papaya and spent a huge chunk of time trying to figure out what was wrong. I noticed the mistake after 10 minutes of staring, time which could’ve been used to finish off the T for Time Tables puzzle quite easily barring any errors.

Round 14 – Doppelgangers (TEAM) (60 minutes) 4740/3600. 19 minutes bonus. 12/12 solved.

Technically, its 6 Doppelgangers solved, but that still makes it 12 puzzles. This was a round having two aspects. First, there were 6 puzzle grids, all of which were solvable using two separate rulesets. Next, these grids were broken into pieces and these pieces were given to us. Participants needed to figure out the relative position of each piece, enter the subsequent clues into the grid on two separate papers, and then solve each puzzle type made by the clues. The doppelgangers were –

Puzzle 1: LITS (240 points) and Star Battle (240 points)
Puzzle 2: Cave (420 points) and Fillomino (300 points)
Puzzle 3: Minesweeper (120 points) and Four Winds (180 points)
Puzzle 4: Masyu (330 points) and Yin Yang (270 points)
Puzzle 5: Nurikabe (330 points) and Numberlink (270 points)
Puzzle 6: Shikaku (220 points) and Cave (680 points)

In this, I took the Cave and Fillomino for starters. This took a while but I got the placement eventually and the solves went pretty quickly as both are strengths. After that, Swaroop gave me his Nurikabe to solve, because he was stuck on it, and had solved the Numberlink correctly. I finished the Nurikabe and by this stage most of the other puzzles were done except the Shikaku and Cave pairing. I’m foggy on whether the Shikaku was finished or not (I roughly remember I did placements for this pairing too, so maybe I solved the Shikaku as well), but the Cave fell to me to finish off, and as the highest pointer, this was pretty difficult. I finished this one with the team waiting and looking on and helping in places. Eventually we ended up with a 19 minute bonus and this felt really good and was a nice end to the day of solving.


This wasn’t the end. After dinner, a recreational team contest was organized by David Bodycombe and his team, just for some light solving after a highly competitive day. This was fun if only because it featured a different kind of puzzle to what we deal with at the WPC. Overall I still prefer grid-based logical pencil puzzles but this was a refreshing change for the evening.

The last recap, maybe even later today, but mostly tomorrow, will deal with the single team round in WPC Day 3, the prize ceremony, etc. I’d like to take this moment to request anyone having photos/videos of Round 15 to send them to me ( so that I can share them and explain the round in a better way.

Puzzle No. 498: Next To Nine Sudoku

This was posted in the Daily League last week but I didn’t get the time to post it here. I’ll finish up the recaps today too. I think.

Rules – Follow regular Sudoku rules. Additionally, the clues outside the grid indicate the numbers to be
placed in the cells before and after the cell containing 9 in the corresponding direction.



Announcing: LMI Sudoku Mahabharat

This August, the Indian team was in London for the World Sudoku and Puzzle Championships. I have been recapping my personal experiences there, and I will continue to do so, with two parts left in the series. However, it is now time to draw attention to one of the ideas that came up during our discussions in London.

A little background first. In 2012, the Indian Sudoku team was decided by the Times Sudoku Championship (A National-level event conducted by Logic Masters India and The Times of India) for the first time (Previously, it was decided by the Indian Sudoku Championship, organized solely by LMI).  Though I would definitely do things differently on the publicity side, and I think it could’ve been a whole lot better, the partnership did cause a substantial increase in participation, going from hundreds to thousands.

The problem is, there aren’t that many new regular Sudoku enthusiasts coming out of it. Especially now Rohan Rao, Rishi Puri and myself seem to be, without doubt, the best three players in India, switching orders in different competitions over the last two years. Sumit Bothra, Jaipal Reddy, Gaurav Korde, Rakesh Rai, Ritesh Gupta etc. are all great Sudoku solvers who are regularly in the top 10, but there aren’t many new faces.

There are many opinions on why this is the case, but for the purpose of this blog post, I’ll put my own out there: It is quite simply because, at the stage where there is highest participation, there isn’t any exposure to the level at which the Sudoku regulars practice. By the time the National Finals with higher variety and difficulty takes place, only the old guard make it. However, this isn’t a problem with an easy solution – you cannot make the earlier round hard as that would demoralize newcomers pretty quickly, and you want a fun event first and foremost. The only solution seems to be to increase the numbers that make the finals, and since it is the sponsors who will need to make added expenditure to transport the finalists, the final decision in this case has to be theirs.

Either way, for any enthusiast thinking it is too difficult to step up into the top Indian ranks, well obviously it isn’t (and shouldn’t be) easy, but it is very much possible to make a quick ascent. Just look at the most recent climbers – myself around 2012, and Kishore Kumar now. The path for both of us has been similar in the sense that we both were regular in online competitions which mimicked the standards of the World Championships. We may have been bad at the new variants at the start, but that’s definitely the level to practice at, and will mostly help to break into the top ranks.


This is where Sudoku Mahabharat comes in (quick clarification – depending on the success of this event, we DO hope to have a Puzzle Mahabharat as well in future years). Is this the only plan to give an opportunity to new talent? No, and there will be other projects announced. But the novelty of this tournament does address some issues. First and foremost, this tournament is organized by some of the regulars of the Indian teams that have been going to the World Championships in recent years. This means most of the top solvers are not competing. The aims of the competition, in relevance to the issues above, are as follows:

1. A competitive format is offered here, and the importance of this can never be understated. Solving a single Classic on a publication or website is different from solving a group of them in a timed format. There is a challenge in both areas, but the National and World Championships are built on a competitive multi-Sudoku timed-round environment. In such an environment, there is room to improve even in Classics for a Sudoku enthusiast.

2. This tournament will provide a look into the variations that appear at higher levels, in a categorized format to help in understanding them. It will also provide both an easy sample of the variant and a more difficult, regular sized version of the variant. The newcomers will have a chance to try out new variants in the easier format, and later move on to the harder levels of the same variants. This structure ensures that every participant has a fun challenge to look forward to.

3. To give new talent the chance to shine in a National level competition. There is hope that this will further encourage the winner to participate more regularly.

So here’s an invite to all Indian Sudoku enthusiasts to a great opportunity. Please visit the following pages to know more about the event, which will also feature an offline final in 2015.

The main Sudoku Mahabharat page:

The Sudoku Mahabharat Discussion thread:

The first round, with Standard Variations, by Rishi Puri, which starts on the 20th of September:

Also, if you want to support LMI in its various projects, please consider being a patron to the group. To know more, please visit this page:

WSC/WPC 2014 Recaps: Part V – Team Building?, WPC Day 1

We return to WSC/WPC week in London, UK at the end of the sight-seeing day. That night was the WPC Q&A. I was extremely sleepy. Its a bit irresponsible of me, but I couldn’t really help it and was half asleep for most of the Q&A. Thankfully, misinterpretation or misunderstanding of rules wasn’t a problem in the next two days. There was an impromptu announcement during Q&A about a WPF General Assembly (or maybe it was announced earlier somewhere and I didn’t notice, I confess I was fully engrossed in other activities in the lead up to the Championships and didn’t read the schedule). Either way, I just think that was a bad time-slot to put it in. The WPC was the next morning. If it was, say, the night before sight seeing day, I’d have kept awake somehow and attended. But since it was obviously important to get sufficient rest before the competition, I decided to go sleep. This presented another problem….

To understand this problem, we need to go back to the day before the travel from India. One of our WPC A team members hadn’t received his passport yet (for some reason, he had applied for it almost two months after knowing he was on the team). Since he was scheduled to travel on the 12th and the rest of us were all scheduled to travel on the 10th, I told him to let us know by midnight on 11th whether he’s traveling or not. Thankfully, we had two B team members, and I could slot one of them into the A team in case this member did not receive his passport. On 11th, he confirmed he isn’t participating, and I made the change, and promoted Jayant Ameta, who was the higher ranked participant at the IPC out of the two B team members, to the A team.

On the 12th, however, I received a mail from the team member stating that he received his passport, re-booked a flight and would arrive on the night before the WPC. He requested to be placed back on the A team, but by this point we had discussed strategy, etc. with Jayant and as it would cause too much confusion to wait until the night before the WPC in uncertainty (not to mention it’d be unfair on Jayant), I declined this request. However, this still presented the problem on the night before the WPC, as I felt obligated to stay up and be around for the UK team in case they needed me (all the uncertainty in the lead up left me fearing more uncertainty on the night). I talked about this to the organizing team, and they said they would manage everything. I am very thankful to them for this, and in the morning he had reached and been allocated a room. So that problem resolved itself, and after a nice breakfast, it was time for the WPC to begin. No, not that wpc, the World Puzzle Championship!

Round 1 – Welcome Round (50 minutes) – 420/750. 11/15 solved.

I missed a high pointer Scramble UK (a scrabble-like puzzle) because I can’t spell. The round had some nice UK 2014 themes. It also had some weaknesses for me (including Scramble UK, why did I try that?!). Add to this the fact that I’m a slow starter and it was a recipe for disaster. Even after blitzing through the 80 point Fillomino, I couldn’t salvage the round, breaking a Triangular Minesweeper and getting stuck on both Digitiles (Oh, that’s why I tried Scramble UK. OK).

Round 2 – The Great Outdoors (30 minutes) – 465/450. 7/7 solved, 1:32 minutes before time.

Yay, a bonus! But eh, almost everyone I would consider myself competing with for rankings secured a bonus here. It was a really nice round, showcasing a well-themed, elaborate and fun way to get Simple Loop out of the way. I blitzed through everything except the Running Trail, and would probably have targeted a 15 minute bonus with a clean solve of that one. The puzzle had a path moving through flags, and having equal length between each flag. Determining the length was a simple calculation as the path(loop) must travel through all white cells of the grid. The length required was 11, and for some typically idiotic reason, I calculated it to be 12, and reached an evil contradiction. It took me a typically huge amount of time to figure out the reason for this and change it to 11, after which I blitzed through this one too. Ugh.

Round 3 – Classics (120 minutes) – 1570/1800. 26/29 solved, 25 correct.

This round went predictably well (me, long round, two Tapa, two Yajilin, a Masyu, and so on, bound to be good) and 1670 was my expected total. Unfortunately, I missed a double bridge on Hashi, which cost me 100 points. Again, typically, I chose the highest pointer for this error.

In spite of this, by this stage I was building a gap between the other members of the Indian team. Rohan had had a great Round 1, but started falling behind after it. Swaroop was steadily scoring just below Rohan and Jayant was doing ok for a debutant. Our placements relative to each other had already started forming the pattern that would stay on until the eventual rankings. Either way, that’s 3 rounds that could’ve gone better, to say the least (learn to spell, learn to count, don’t leave out double bridges. Important lessons for any aspiring puzzler out there). Anyway, after a break for lunch, there were 4 more rounds:

Round 4 – Latin Squares (60 minutes) – 590/900. 11/17 solved.

I expected to do better here, considering I do well in that other Championship… I broke 2 Fuzulis, Made a mess of some others too, and ended up with a decent score. I think I beat Palmer Mebane on this round, but can’t be sure. Also, I’m horrible at Mathrax.

Round 5 – On Your Own (45 minutes) – 200/600. 5/9 solved, 4 correct.

This was an Instructionless round where I didn’t do well at all (I guess Round 5s are just not for me. Petition to have Round 6 be after Round 4 from next year? Maybe). The rules were to be figured out from solved examples. I have three things to note here –

1. This was a nice way to get Hex Puzzles out of the way as well (All puzzles in this round were Hexed variants).

2. It is always difficult to execute an Instructionless round without clarity issues and nondeductible rulesets. Considering that, this round was really well done, even though I messed it up personally.

3. There was, however, one clarity issue. One of the puzzles had a rule that all cells must be passed, and this rule wasn’t expressly indicated and just implied by the solution having all cells used. Maybe I’m just bitter as I got this wrong because I didn’t obey the cell-usage rule, but probably a valid negative feedback.

Round 6 – Sprint (30 minutes) – 440/600. 14/19 solved.

The reaction to this round was unanimous among the participants I spoke to later – “What on earth were those No Four In A Row puzzles doing on a sprint round?!”. So yeah, there were these 2 50 pointer No Four In A Row (A.K.A. X and O) puzzles, which were either really difficult or required bifurcation. Either way, considering this was not a strength anyway, I struggled badly on them and (at least among the people I spoke with) so did anyone who decided to attempt them. Why attempt them when it wasn’t a strength, you ask? Because on one of the pages was a Walls puzzle, which was probably covered by invisible walls, because I completely missed the page. I forgot they were on this round, and thought the only other option was the Unequal Length Maze, which is an even bigger weakness. I am good at Walls, so this was a big miss and a big disappointment for me. Also a big disappointment? Because I missed these, I thought the only ones I didn’t solve were a No Four In A Row and two Unequal Length Mazes (20+20+50=90). Finding out about the Walls page meant I had missed another 70 points. Ouch.

Round 7 – Table for Four (Team Round) (60 minutes) – 2400/3600. 3/4 solved. 1 horribly messed up in four different colors!

This was another of those rounds with 4 different color pens, like in the WSC, but here we didn’t have to rotate the sheet. There were 4 different sets of clues, oriented differently so everyone could read their own clues normally, and you only had to solve the ones of your color. Communication was much more flexible here though, so we got through fairly quickly with the first Snake Pit puzzle, and the Tetromino and Pentomino puzzles went smoothly too. Then we reached the Battleships. The logic hidden here was really nice with many ‘squares’ restricting where the longer ships can go. Eventually we thought we had eliminated all other possibilities and proceeded with a configuration for the longer ships, but kept reaching a contradiction. In the end we made a quick guess and ended up with extra blue segments. Oops. Anyway, we knew this would be wrong, so it wasn’t a good round, considering many teams had finished. But in perspective of one of our teammates being a debutant, this was ok.

The Next recap will be about WPC Day 2.

Puzzle No. 497: Odd-Even Count Sudoku [Daily League]

The WSC/WPC Recaps will resume tomorrow.

Remember that you can solve the puzzles from the League online on the Sudokucup Guest League page with a 24h delay.

Rules – Follow regular Sudoku rules. Additionally, An even number placed in a cell with a circle indicates the number of even numbers placed in the surrounding 8 cells. An odd number placed in a cell with a circle indicates the number of odd numbers placed in the surrounding cells. Numbers placed in cells without a circle may have either of these properties.



Puzzle No. 496: No Nines Sudoku [Daily League]

I am having a whole lot of net issues right now, and before that I had a few projects to take care of, so the WSC/WPC recaps are temporarily paused. I’ll resume in a few days I think. Anyway, for now, I return to the Daily League on Saturdays. Here is a No Nines Sudoku I had written for Team India’s practice before the WSC.

Rules – Place a number from 1-9 in each empty cell in the grid such that each row, column and marked 3×3 box contains each number exactly once. Numbers placed in adjacent cells must not sum to 9.



WSC/WPC 2014 Recaps: Part IV – WSC bids, sight seeing

This one’s probably gonna be a little strong. Lets just jump right into it.

Right after the WSC closing ceremony, some of us were invited to a room to watch and discuss a presentation of some sort. This was mostly a last-minute thing because not that many people showed up. The people hosting the meeting were Puzzlium Inc. – represented by three Ukranians based in USA. Their presentation was related to a bid to host WSC/WPC 2015 using their app, Puzzlium.

I’ll first note down their proposals, as I understood them. Note that this is not an official post, I was just a spectator there who discussed some of these points during the meeting too. Since I am not personally a WPF member (and some others present at the meeting weren’t either), this seemed to be an open meeting. This seems to be an impromptu chance given by the WPF to the presenters to make their case in front of a group of WSC/WPC competitors. Anyway, what they planned:

1) The WSC and WPC would be in the USA, and the participants would attend as usual, selected by their respective countries. However, the solving would not be done on paper. Each participant will be given a device that supports the app, and the solving would have to be done on the device.

2) All puzzles would be created using the App, which automatically tests for solve-ability and uniqueness. No human dependency and so, zero chance of unsolvable or non-unique puzzles.

3) Even though the official participation would be on-site, anyone who purchases the app could participate in the same competition from their homes, as the puzzles would simultaneously be available for everyone on the app.

4) Printing costs saved, and all that financial stuff.

5) The difficulty will be decided in a dynamic way, based on a formula dependent on solving times for each puzzle as they were solved.

Now, my general reactions, including some things I didn’t mention on site, either because I thought they weren’t relevant to the organizational side of things, or because I thought of them only after further reflection.

Firstly, I’ll put up the point that was seemingly unanimously agreed upon by the puzzlers present there (but one that the presenters didn’t seem to fully grasp). We have National selections in each of the member nations and this selection process is what decides the teams eligible to compete at the World Level. This is similar to all World Level competitions. The Olympics don’t have officials sent to each home to ask the people to race and see if they are as fast as the competitors. They may or may not be, but that’s not the point. The World Championship is for those chosen to be the best at what they do. I fully support a process which encourages everyone from their homes, as a separate Championship, or even at a National level – but not the World Championship. Their way of combating this was to repeatedly ignore it and go on about how everyone must get a chance. I agree with that, but that should be before the World Championship, during National selections. Everyone must get a chance there.

Upon further reflection, I’ll add to this point – Just because they open it up to everyone using the app does not mean that they are taking the Championship to everyone either. It is simply opening it up to people who have heard of the App, have the money to purchase a device that supports the app, and have enough time on that weekend to devote to solving puzzles all day. Hardly a comprehensive selection. In fact, it is ironic that they used the argument for this that people might not be able to spend money to participate at the WSC/WPC, when money is obviously required for this too, unless they plan to send a free device with the app to every home in the world.

Another valid point brought up from our side – solving on the app means only using markings built into the app. This may be ok for Classics, but going to the rarer variations, and for puzzles different solvers have different notations. The most immediate example I can come up with for this is Fillomino, where some mark borders, some write in numbers, and some, like myself, draw lines passing through the middle of cells. Even if the app supports all of these solving processes, there may still be something I’ve left out that some other solver feels comfortable with. Limiting them to the possibilities of an app is not fair in competition. In reply, they said the app’s solving would be dynamic but did not feel the need to expand on this and resorted to the stance of  “this is a technical limitation which we will look at”. This is just one example, but there may well be many solvers who are at a disadvantage here for reasons other than puzzle-solving.

The third concern, is about the creative levels of a World Puzzle Championship being restricted immensely by the app. Some of us did raise this concern, as the only puzzles they could demonstrate to us were very simple in nature, and did nothing to indicate that they would be capable of designing an app dynamic enough to carry the variety required for a World Championship (108+70-ish types that appeared over the week in London this year, for example).

Also (something I didn’t talk about there as it didn’t seem fully relevant), as a puzzle author, I take offense to the insinuation that any random app can be as creative and innovative with puzzles as a human author can be. Its not that I don’t think this is ever possible – after all, human minds are the ones designing new technologies, and maybe in the future, a computer has an artistic artificial brain and is capable of innovation in our field. But this isn’t gonna happen anytime soon, and more than anything, there is no way you will convince me it is just by showing geometrical variants of Sudoku and a few dissection puzzles which appear random as far as themes go. Will they have cute themed rounds like the Great Outdoors, or English Country Gardens, as at this year’s WPC? Will they have a “Something New-ish” round with innovative variants? Will they be able to have an entire round each for Math variants, Neighbourhood variants, Geometric variants, Outside Clue variants, as at this year’s WSC? I have minor criticisms of this year’s World Championships too, but they are just that – minor. They are nitpicks based on personal preferences, but in general, the World Championships were of a high quality (and just happened to be one of the best ones I’ve participated in) which I don’t see being replicated by an app anytime soon.

The other big problem is the dynamic difficulty assignment. This completely eliminates strategy based on points (and also calls into question the presenters’ claim of going through WSC/WPC booklets and studying how things are done). They responded to this by saying they will have a group of pre-testers who will not participate which is fine, but negates one of their “positives” all the same. There were other topics that weren’t even brought up (mainly because some of these points turned into repetitive arguments that took us late into the night) like malfunctioning devices, or team round management, or the fact that to practice on the app for the WSC/WPC we still had to purchase a device which seems an unnecessary necessity in relevance to solving puzzles. But since I believe the points brought up at the meeting were more than enough to prove that this isn’t a good idea, its alright. Some suggested a compromise of one round being devoted to their software as a gimmick round, and as long as this is a low weight-age round, I have no issues with this plan, even if I won’t be a fan of it.

Ok, now moving on from all of this to a much lighter topic, the next day we had the Team photo followed by sight-seeing. Here, we saw Big Ben, which we learned was renamed, and is now known as Elizabeth Towers. We also saw Buckingham Palace and the Queen’s Guard. After this, the Indian team wanted to separate, as some of us wanted to finish some shopping, so I went with them.

During the time with the group however, I was mostly talking to Jarett Prouse and Fae Lau of Canada B (Yes, they Can B!) about the various ways guides directed their groups. We agreed that Magical Stuffed Fox was the most awesome guide-help (I was skeptical of it being magical, but Jarett insisted), but our own guide’s magical umbrella came close. This time, I can elaborate on why this was magical – each time our guide Sally raised the umbrella, the traffic stopped. This kept happening, about 4 times. At one point, I shouted out “UMBRELLA” just to see if it happened that way too, and it did! It was creepy. Anyway, we also agreed unanimously upon the worst guide-help among the ones we saw – a home-made “Follow Me” scrawl propped up on a stick. Ouch.

There was also a story about Canadian Geese in there somewhere, which was pretty entertaining, but I have apparently forgotten it now, so can’t go further. So I’ll fast forward to when I was with the Indian team, and we got back to the buses to get back to the hotel. 3 of the team were leaving at this point, to begin the journey back to India, as they were only there for the WSC. Deb Mohanty, Rishi Puri and Sumit Bothra all needed to get to the airport by the evening and couldn’t accompany us back to the hotel because of this. Goodbyes were said, and the rest of us got back on the bus. It was on the journey back that I spotted a restaurant with the best name any restaurant can have – it was solely titled “EAT.”. I like that. Anyway, other than that it was an uneventful trip back

Next time, I’ll post about certain complications with the Indian Puzzle team, and WPC Day 1.