Puzzle No. 509: Triomino Sudoku [Daily League]

I’ve got wayyy too much to do these days, so I’ve pretty much stopped any regularity on this blog. I might make the rare post though, like this one. I was a little bored of work and had some time so quickly explored this variant that’s part of the Indian Sudoku Championship which will be held online on LMI in about 13.5 hours. This one is pretty difficult (as are all variants I randomly and quickly post here when bored), but has some nice steps to get started.

Remember that you can solve the puzzles from the League online on the Sudokucup Guest League page with a 24h delay (though I’m not yet sure if this one can be supported there, but take a leap of faith, maybe it will be!).

Rules – Place a digit from 1 to 6 into each empty cell or blacken the cell so that each digit appears exactly once in every row, column, and outlined 3×3 region along with three black(shaded) cells. Each black(shaded) cell should be part of an orthogonally connected group of three blackened(shaded) cells (a triomino). No two triominoes can share an edge.





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: http://logicmastersindia.com/SM/2014-15.asp

The Sudoku Mahabharat Discussion thread: http://logicmastersindia.com/forum/forums/thread-view.asp?tid=868

The first round, with Standard Variations, by Rishi Puri, which starts on the 20th of September: http://logicmastersindia.com/SM/201409/

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: http://www.patreon.com/logicmastersindia

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

Apparently, I was wrong about getting the bonus on Round 7. Should’ve known looking at the points, but eh. Anyway, Day 1 was made so bad by Round 5 that I was just hoping to climb a little bit in the rankings on Day 2. Last year, I was 27th and with 3 rounds in Day 2, climbed to 15th. This year, there were just two rounds in Day 2 and I was 28th up to Round 5. Though the Round 6 results weren’t out yet, I knew the climb wouldn’t be much in that one. I also knew that coming up was my favorite round…

Round 9 – Endurance round (90 minutes) – 16/17 – 870/940.

Before this round started, the UK Organizers had to handle a slight misprint, so they made us turn to the page with the Between Sudoku, where there was an extra line, and informed us about it. I thought this was a good simple way to handle it, and also noticed a nifty WSC theme for the lines of the Between Sudoku as I was correcting the bad line. We then had to close the booklet again and wait for the start. I solved mostly in order, with Windoku, Diagonal (I didn’t try it as a Classic this time!), Anti Knight and Palindrome getting done pretty quickly. I noticed another WSC theme with the shaded areas of the Renban Groups but skipped it as I don’t feel that comfortable with the variant. This would end up being the one I didn’t attempt on the round. I solved everything except the (Renban Groups and) Eliminate Sudoku with about 12 minutes left, and I thought I broke it for a minute in between, but it turns out I had eliminated a possibility which wasn’t forced by the eliminators. Maybe I’m an arrow too. Anyway, fortunately I recovered from this and finished the Eliminate Sudoku with 2 minutes to go. At this point, I knew there was no way I was finishing Renban Groups in under two minutes, so just went about checking for empty spaces in everything. There were none.

Round 10 – Overlapping Scattered Sudoku (20 minutes) – 1/1 – 130/100.

I confess I was dreading this round. I hate all such all-or-nothing rounds where its just one Sudoku to solve, because the difficulty is at the organizer’s discretion, and harder ones can lead to some unnecessarily high variance in the scores. To the organizers’ credit here, this one was easy enough to be ~10 minute solve in general, and indeed, some of the best times on it were 7 minutes. Rohan did really well here and finished in 8 minutes, but this wasn’t enough to get him in the top 10 unfortunately, and he finished 14th. Me? I had a repeat performance of my Times Sudoku Championship 4th round earlier this year, which was a Samurai with a similar round structure. I solved the entire thing, spotted an error, erased the entire thing, and re-solved the entire thing. There too, Rohan finished earlier than me, but there he made a mistake and I ended up having best score on that round. I’m really thankful he didn’t make a mistake here, but I also wish I’d stop making these Overlapping Sudokus into Double-Solve Overlapping Sudoku variants. Anyway, I still managed to finish with 3 minutes remaining, which was ok, but dashed my hopes of being within the top 20.

I finished 21st. Rohan, as I said, was 14th, Rishi was 36th, and Sumit 55th. If only Rishi was 35th and Sumit was 56th, we’d all be multiples of 7. I am thoroughly disappointed that this didn’t happen. Or maybe I’m just projecting my disappointment of my own performance over there. Something like that. Anyway, there was one team round to go, which didn’t need as much co-dependence as rotation or stripping… I mean Strip Sudoku.

Round 11 – Team Round – Linked Sudoku – 5/5 – 3360/3000.

Like I said, this didn’t have as much co-dependence as the previous team rounds. The structure was simple. There were 5 Sudokus, a Killer Pro, a Diagonally Non Consecutive, a Toroidal, a Sum Skyscraper, and a Musketry Sudoku (Overlapping grids). Each of these were uniquely solvable but were really difficult. There were some letters marked in some cells in each of them, and same letters would be the same digit throughout. e.g., if there’s an A in the Toroidal and the Musketry, and if A=5 in Toroidal, it’ll be 5 in the Musketry too. So it was a simple case of solving each of our own variants and communicating a letter’s value if determined. All the variants were strengths for me, so we went a different route and I took the one which was everyone else’s weakness – Toroidal.

Rohan took the Diagonally Non Consecutive, Sumit took the Killer Pro, and Rishi took the Musketry. We managed to solve things smoothly enough, and Rohan was the first to finish his I think, so he began working on the Sum Skyscraper. Sumit finished Killer Pro around the time when I had made the Toroidal easy enough to just have the last bit of filling done. Sumit grabbed the Toroidal and told me to help Rohan with the Sum Skyscraper, but almost immediately threw it back and told me to finish, because again, he couldn’t read my handwriting to finish (at this point I think it is only appropriate that I submit my humblest apology to the markers who had to put up with the handwriting that my team cursed on day 1 and gave up on on day 2). Anyway, not much damage done, as I quickly finished the Toroidal, and went over to helping Rohan with the Sum Skyscraper. We managed to finish this as a team, since Rishi was done with the Musketry too. We finished the round with 9 minutes to go and ended the WSC on a positive note.

We had been ricocheting between 7th and 8th in the Team standings throughout the WSC, so we expected a 7th with the last team round being good. A 7th would’ve tied our previous best ranking at a WSC, one which we have achieved twice before. However, the French team who were 6th for most of the WSC, were kind enough to goof up in the last team round, making an error that cost them almost 2000 points and pushing them one point behind USA, down to 8th. We got pushed up to 6th, making this our best team ranking, and also a newsworthy fact for our sponsors to report.

The funny thing here is, we wasted a whole lot of effort trying to get the UK WSC logo in the background, only for Times to photoshop it out anyway. I’m guessing its because of some policy against publicity to other brands, or something. I would probably not do that, but its their paper, their policy, no issues.

Anyway, I confess I went to my room and slept through the WSC playoffs, but only after proving how horrible I can be at Tennis, playing against the rest of the Indian team. The playoffs this year had a better structure than recent years simply because the top 10 were divided into groups, with the final group being 1st-4th. This means the preliminary rounds winner can only drop to 4th at most, so at least in my opinion, it was a fairer structure. The playoffs apparently went fine, except for a minor glitch – in the final playoff, the markers judged a correct solution wrong somewhere, causing minor confusion. This did not impact the top two, so it was resolved simply by declaring a tie for 3rd place. The top 3 were as follows:

1. Kota Morinishi (Japan).

2. Tiit Vunk (Estonia).

3. Bastien Vial-Jaime (France) & Jakub Ondroušek (Czech Republic).

I congratulate the winners, and going by performances in online contests over the past year, this is a fair reflection of the world’s best solvers. Also, this was a WSC which was a lot of fun, and left me wanting more. My only criticism is a really selfish one – it needed more long rounds. It is down to personal opinion and strengths and weaknesses of each competitor I suppose, but as far as preferences go I will always prefer the longer rounds. Maybe next time I should just ask the organizers if I can sit and solve all the rounds at a stretch…

Anyway, that evening, the WSC closing ceremony took place. I cannot begin to explain just how entertaining this turned out to be. The Indian team table probably had laughter throughout dinner. We just could not stop joking around, not that anyone wanted to. Within all this though (literally within all of it, we somehow managed to keep joking), we also discussed some serious matters. The discussion inevitably went to Logic Masters India’s future plans. We have come a long way from the Mock Tests that started on LMI, to having themed contests, Annual feature Contests and Beginners’ Contests. Every puzzle enthusiast probably knows what we’re about by now, so I need not go further. This year we started our patronage system to get some funds, in order to progress things in India. So apart from all this, we discussed some new ideas, which will probably be publicized in the near future. Most of these ideas go towards finding and developing talent within India, but there may be something to interest International competitors too in the process. Either way, stay tuned.

That’s all for this recap. The next one contains controversy, magic and Canadian Geese!


Update – Parallel Universe II – Inversion Invasion

So just a quick update for those of you who haven’t seen it yet – My second contest in two weeks at Logic Masters India. Last weekend it was Parallel Universe, the Sudoku Contest. This weekend its Parallel Universe II – Inversion Invasion, the Puzzle Contest. You can participate anytime within the next 40 hours (ends at 4/29/2014 5:29:59 AM local time | 4/28/2014 11:59:59 PM GMT).

Btw, the other Universe’s Prasanna prepared some PracticeFromTheirPSv1 (These are the same as the ones on LMI). He told me they are prepared in a rush so he didn’t have time to work up almost-symmetry in a lot of them. Even so, I think they’re good for practice of the newer types.

Puzzle No. 494 : Inner Tripods Sudoku [Daily League] [Invasion]

Greetings from another universe! After the Prasanna from your universe wrote a contest for LMI based on a few variants from our universe, the Inter-Dimension Puzzle Wizard notified me of the same. I decided to launch a translation of your wacky variants and a clarification of what you call our normal variants, for the people of my universe who might want to solve these Sudokus. The Prasanna from your universe was kind enough to include this as a separate “TheirUniverse” PDF.

That gave me an idea that I should probably write a Sudoku for something, featuring another one of our variants that has the same name as one of yours. Me and the Prasanna of your universe went through the list of variants in my universe, and he liked our version of Tripod (Again, your version is so wacky, but interesting), so I wrote a Tripod that we decided to use for the Daily League!

Your universe’ Prasanna got a chuckle out of this fact, but in our universe, “almost” symmetric puzzles are considered as having better aesthetics than fully symmetric puzzles. Maybe someone is interested in this fact, and in the Sudoku I wrote.

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

Rules – Rules for Sudoku. Additionally, in the grid there are “tri-pods” with a “seat” and 3 “legs”. The seat, and the “feet” of the legs are denoted by dots. The “seat” of a tripod must have a digit thats greater than each of the “feet” but the sum of the “feet” must be greater than the “seat”. Digits can repeat in a Tripod.




Puzzle No. 493 : Maxi Loop + LMI Patreon Update

Hello, dearest readers! Its… been a while. Sorry about that. I feel I’ll have more time for this place come May. For now, I’d like to draw your attention to the fact that Logic Masters India has started its own Patronage system. Please check out our page on Patreon and on LMI itself. The Puzzle pack rewards are currently all written by me, but future ones will definitely have other Indian authors involved too. If you like the hosting features LMI has to offer and/or find the rewards enticing enough, please consider supporting us. I’ve taken up a few things on behalf of LMI here in India, all towards making our group more recognized in the country. Funding certainly helps this.

Anyway, I feel a little bad that I’m only making a blog post when I want to promote something, so here’s a Maxi Loop puzzle to go along with it. I hope you enjoy it!

Rules for Maxi Loop.

Rated – Easy with a slight pause.