Does converse rule apply in division Sudoku and equal product Sudoku?

It doesn't apply to equal product Sudoku.

Edited by aditi2302 2015-11-07 11:55 AM

No and No. For Equal Product, it is very clearly mentioned in the instructions.
Btw, you may enjoy the Converse round authored by Rakesh/Harmeet on 13th-15th Feb, 2016 :-)

What are converse rules?

Look at last year's converse round - http://logicmastersindia.com/lmitests/?test=SM201503

Solutions of all Standard sudokus in the math variations IB are different from the example questions. Please check.

Can we solve example/Instruction booklet online? If so, how

It is a good time to remove the solutions of the Standard Sudokus from the IB. Done that.

You can now solve few examples on the submission site online ( http://logicmastersindia.com/SM/201511/?online=1 )

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

Really fun variations. Thanks for monthly diversions.

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

Phew ! That was a nice ,interesting and a really hard set.Some of the ideas both from a solving perspective and a construction point of view were really novel.The bunching of clues in Group sum 6X6,the really neat layout of Tiles in Killer(7) to name a few....

I feel compelled to describe my experience of the test a bit in detail as it was something of a roller-coaster ride.

I started with the Division 6X6,slipped on it and after that it was smooth sailing through Sum Frame and Killer until I hit the vicious Equal product(13).

I was one of the poor victims of missing the possibility that a 6 can be in Box 9 in R7C7.I proceeded by missing that possibility and broke much later and was left wondering where I might have gone wrong.Kept starting again,kept missing that possibility and kept wondering until eventually I came to the conclusion that I needed to be workman-like and eliminate digit by digit.That's when to my devastation and amusement (to a little extent) that I
realized that I had missed 6 in R7C7.With these kind of sudokus, I realize that it might be much better to have pre-prepped notes of all possibilites of Equal products...

So that was it! 28 mins lost on a single sudoku.Then I rushed through the Classics without much difficulty albeit with a lot of panic after having lost a lof of time.

Came to the Group Sum genre at last and was as lost as a blind man in a dark forest at night time.Was utterly clueless where to start seeing that bunch of clues in between.Kept shuttling between Group sum(15) and Group sum(7)as if I were playing a simul chess game like a Grandmaster.

Realizing that, that is a highly futile attempt which will yield me little in the way of points ,I decided to confront the 'bunch sudoku' and had a highly lucky guess going right my way the second time.I convinced myself that either R3-4/C3 or R3-4/C4 had a total of 11 (a 5-6 pair).I had no clue why I assumed that way :) Call it intuition :-p.....Started with the wrong guess the first attempt and the second time got it right.

I also observed that in my case the 6X6 sudokus had a lot of sting equal to if not more than 9X9 .

To conclude, a test with beautiful and really hard sudokus coming back just on the heels of a difficult Evergreen round but knowing now that the scores are aligned to the best scorer,I must state that it seems perfectly fine to have hard tests like this to learn some new stuff .

Thanks a lot Rohan!A delightful test with some really novel ideas in solving and construction in particular.I had great fun!!

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Below Average
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth too much or too little

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many medium difficult puzzles
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

Thanks for the nice test !

I really enjoyed !

My mistake was to think it would just be a small tournament with easy/medium sudokus, so I don't have to print the pdf (some cartridges of my printer are empty and I was too lazy to replace them), playing online should be ok. So I started the test while a bit tired and thinking it would just be relaxing time.

I'm not a big fan of sum frame sudoku, as I think it's globally always the same logic, it's impossible to have a real surprise with this variant.

On the contrary, I think group sum sudoku has big potential of being really interesting. I created my first group sum sudoku last year for the WSC swiss qualification and I think it's possible to create very nice group sum. One may think it's just about the same as killer sudoku, but I think some aspects are really different. And I must admit I haven't been disappointed during the test. Both 6*6 and 9*9 group sums were 10-stars sudokus. I think I was very efficient on the 6*6, I was quite fast at noticing the pairs 12 in rows 2 and 3. I had the beginning of the 9*9 quite fast, too. But unfortunately made a mistake, and had to start again. Then I eventually learnt a new trick on this 9*9 group sum sudoku. Very nice, thanks Rohan for this one !

Then came the equal product sudoku, and on the 9*9 I had hard regrets not having printing it. Not being able to write notes outside the grid was fatal for me. I made lot of very stupid mistakes by forgetting some possibilities for products many times while solving (it finally took me more than 30 minutes to solve it, haha !)

The only little critic I could make is that the tournament was perhaps a bit hard for the intended purpose. I was a bit surprised, but it was a very nice surprise for me ;)

Fred

Thanks Kishore. I had predicted you would score 85 before the contest began :-)

Thanks Fred. I'm glad you enjoyed.
I agree the test is a little hard, and that was intended.

I really loved the 6x6 Group Sum, it was my personal favourite of the set. The 9x9 Group Sum has a very narrow solving path, but logical.
The Equal Product 9x9 is tricky. I think if you do your homework well, it is a Medium-difficulty sudoku. It uses a lot of deductions from the crosses.

I definitely agree. I solved it like a dilettante and had to face a lot of contradictions while solving because I was too lazy to really take it in a logical way, that's why I wasn't efficient on this one.

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many medium difficult puzzles
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

Ah really? That's interesting.Next time,if you do, predict that I complete the test in 'X' number of mins :-p

Haha! Well, I can only predict in tests that I author! So, next year :P

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Fairly Nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth too much or too little

How on earth are the small puzzles worth that many points? I solved quite a few of them quite a bit faster than I solved the classics.

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Fairly Nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

Got a bit stuck initially, but enjoyed solving post hoc. Good set of puzzles !

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Fairly Nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Fairly Nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

@ admin. i just submitted my answers around 3-4 minutes back . but had forgotten to log in. please do the needful.

Not exactly sure what that means. I can see you have got 65

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many medium difficult puzzles
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

How well did the variants represent the theme of the test ?	representation could have been better
What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Fairly Nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

How well did the variants represent the theme of the test ?	representation could have been better
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Fairly Nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Average
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Average
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little

Can X take a value > 90?

X Takes a value > 90 in PR rounds and
X < 90 in SM rounds

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Very nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little

I'm not quite sure what is trying to be achieved with the 50% easy, 40% medium, 10% hard distribution - the last few competitions have felt very disjointed with many puzzles you can breeze through before getting held up by one or two much harder puzzles. My personal preference is to have a much more even difficulty level.

This is to take nothing away from the individual quality of the puzzles - in isolation each was very nice!

Updated Sudoku booklet uploaded - password removed and solutions appended.

Leaderboard updated too.

Congrats to Kishore, Jaipal and Rajesh for the top Indians and to Tiit,Kota and Nikola for the top international players!
I really enjoyed creating this set, and personally liked it much better than most of my previous sets I've authored on LMI.

There is some feedback on sudokus being hard. Yes, that was intended. Since this is mainly targetted for the Indian audience, we are trying out different approaches to see how best to expose and challenge the players with different sudoku variants. When we initially started SM last year, we had a thumb rule that Classics should be ~ 20% of the points. It worked really well in my opinion. Now that we've changed the scoring system to normalize the points, tests can have varying difficulty without much effect on the score distribution of players across the rounds.

(1) Some of you voted for 'representation could have been better' -- Any comments on this will be helpful. Though, its likely the question is misunderstood :-)
(2) Many of you voted for 'too many hard puzzles' -- Totally understandable.
(3) Most of you voted for 'very nice puzzle quality' -- Thanks for that and glad you liked it.
(4) Few of you voted for 'many puzzles being worth too much or too little' -- I disagree here. If you look at the score-page and sort by # correct submissions, it is almost in reverse order of points. Which is the ideal scenario!

I also realize (4) can be interpreted in multiple ways:
-- Easy puzzles had more points and hard puzzles had less points
-- Very few puzzles contributed to large proportion of points and too many puzzles contributed to less proportion of points

I'm not sure what players are thinking while choosing this, but we expect the first one. Any feedback here will be useful. We might change the wordings :-)

Overall, I'm glad most of you enjoyed the puzzles. Nice to see 340+ participants with over 100 Indians.
Looking forward to the next SM round of 'Outside' by Rishi.

I think this is the right way forward - i.e. different rounds having different difficulties. Having all easy sets (like last year) will eventually be monotonous in my opinion.

I think both of your "alternative" interpretations of 4 are far more valid than the one you seem to have picked Rohan. What you have written implies that rational solvers should be naturally discouraged from trying harder puzzles because there is less chance of them finishing them and claiming the points. Which seems to run entirely contrary to the idea of exposing newer solvers to these harder puzzles, which is presumably what this 50/40/10 distribution is all about.

Aahhh, I see what you mean now. This is a valid point. In fact, this did come out when we were discussing the format of the rounds internally, but that was over a year back and things have changed since then.

Thanks for bringing it up, we'll think through this and hopefully have better rounds in the remainder of the series.

It seems like it might make sense to change the scoring system. While the rounds may generally vary in difficulty, it seems like the top score for each round stays around the same value. As a result, while there may not be certain rounds that everyone drops because they are difficult, if everyone who is not in the top group finds the test more difficult then there will still be large numbers of people dropping the test because they performed worse on this round relative to the top score. This is not just a problem for international results but also for the Indian results, since it seems like Rohan's score is pretty consistently at the top and around the same value.

In addition, this leads to another problem for the Indian results which is that scores may be too dependent on who is taking the test rather than the difficulty (this isn't really present for the international results since there are so many top scorers). For instance, since Rohan authored this test and could not take it (it is hard to say how he would have done), the top score was lower and thus everyone's scores will be inflated.

Maybe a better way to calculate scores would be to include some measure of one's ranking in the round. Or maybe include the median score in the calculation somehow.

Standardising a series of puzzle contests is a very interesting problem, and one that was considered at the 2013 WPC. Assuming a range of 0-100, the median rank by raw score was given 50 and the lower half of the field given a score between 0 and 50 in proportion to the ratio of their raw score compared to the median raw score. For the top half, it's a similar story except that 100 points was given to the 10th (I think) rank, with 1-9 getting more than 100 points. This was done firstly to fairly reward exceptional solving whilst not penalising anyone else - the thinking being that by the time you got to 10th then it doesn't matter so much who was in the contest.

That WPC had the additional problem of calibrating those standardised points to the rest of the competition, but it seemed to more or less work out.

Since then I've had thoughts on how to improve this, and I have a system which I think would work really well which I never got around to trying beyond playing with some croco puzzle data. Id be happy to play around with the scoring data from this series this weekend if I get a chance...

We had the same discussions when we created the LMI Ratings ( http://logicmastersindia.com/forum/forums/thread-view.asp?tid=119 ) five years ago. I agree with the points raised by you. As a matter of fact, we already have normalized scores (NS) available for these tests which takes into consideration score, rank and median. It would be interesting to see if the results are any different, though.

Yes, we're aware of this. In fact, the Math round is high scoring for most players and wouldn't get discarded, and so the only person who doesn't benefit from this is me. But that's fine, considering these scores are only a preliminary selection for the national finals.

But standardizing a series is not easy, like Tom mentioned, and some of the ideas that have been tried out seem to have worked (with WPC 2013 as a classic example). It will be interesting to see if these work under different circumstances or whether they are specific to a particular series or type of contest.

How well did the variants represent the theme of the test ?	variations represented the theme well
What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Fairly Nice
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount