Logic Masters India announces the August Puzzle Test 'Broken Pieces'

Have you enjoyed solving jigsaw puzzles (as a kid) or mechanical sudokus? Here's your chance to explore this concept into the area of puzzles and showcase your ability in joining pieces together to solve a puzzle.

You can download the IB here: http://logicmastersindia.com/M201008P

Hope to see you all participate!

Players downloading the Instruction Booklet should download the Booklet for Samurai Sudoku and should start planning how they will solve it :-)

can u be more explicit in the instructions in samurai sudoku..............
I mean will we have to use the same broken pieces given in the IB?

Yes. The 16 pieces given in the IB is final.

In the actual puzzle, the Samurai Sudoku will have 16 shaded 3X3 boxes. You have to put these pieces in those 16 shaded boxes.
Additionally, the Samurai Sudoku will have some givens (hints) as well.

Is that clear?

Broken Pieces bonus puzzle

A bonus puzzle for Broken Pieces can be downloaded from here

Notes
• No points for solving the bonus puzzle. So, don't solve it when you are taking the test.
• Since it is just a puzzle for fun, you might find it tricky. But the difficulty level of the bonus puzzle has got nothing to do with the difficulty level of the actual puzzles in the test.

Share your feedback, if you solve it.

Thankx a lot..........yup its clear now........

Chinese version of IB, please check http://www.sudokufans.org/forums/index.php?showtopic=102

Thanks Deb for the bonus puzzle. Very nice and innovation concept.

Nice puzzle Deb. There were a lot of useful common cells amongst the 8 options.
I do hope that the broken pieces puzzles will be easier.

I've solved some of the BP puzzles, and they are definitely easier.
Rohan to answer if all BP puzzles are easier than this bonus puzzle or not.

The Sudoku tests have different submit button for each puzzle.
But there is one Single submit button for the Puzzle Test.
When you click on the Submit button, all modified answers will be submitted. (modified = modified since you last submitted)

Example :
You fill in puzzle 1 and puzzle 2 and click on Submit.
You will get a message "Answer to 2 puzzles (2 new answers) were submitted at server time 8/26/2010 8:29:30 AM. 89 minutes and 40 seconds remaining."

After that you fill in puzzle 3 and puzzle 4 and puzzle 5 and click on Submit
You will get a message "Answer to 5 puzzles (3 new answers) were submitted at server time 8/26/2010 8:39:30 AM. 79 minutes and 40 seconds remaining."

After that you fill in puzzle 6 and puzzle 7 and click on Submit
You will get a message "Answer to 7 puzzles (2 new answers) were submitted at server time 8/26/2010 8:49:30 AM. 69 minutes and 40 seconds remaining."

After that you realize that you have made a mistake in filling puzzle 5. You change the answer for puzzle 5 and Click on Submit.
You will get a message "Answer to 7 puzzles (1 new answers) were submitted at server time 8/26/2010 8:59:30 AM. 59 minutes and 40 seconds remaining."

After that you don't make any changes, and click on Submit
You will get a message "Answer to 7 puzzles (0 new answers) were submitted at server time 8/26/2010 9:09:30 AM. 49 minutes and 40 seconds remaining."


So, the submission time for each puzzle will be according to when the specified puzzle was last submitted.
In the above case, the submission times will be as below.
P1 : 8/26/2010 8:29:30 AM
P2 : 8/26/2010 8:29:30 AM
P3 : 8/26/2010 8:39:30 AM
P4 : 8/26/2010 8:39:30 AM
P5 : 8/26/2010 8:59:30 AM
P6 : 8/26/2010 8:49:30 AM
P7 : 8/26/2010 8:49:30 AM

So, you can submit as many times as you want, before you time ends.
At any point in time, you can look at the message and see how many submissions are recorded.

Hope this is clear and as desired.

( NOTE : the time that you see in the message will always be in IST)

Did anyone else solve the Bonus puzzle?

I solved bonus puzzle yesterday and it is really nice puzzle as other said. Every next move and common cells in left pieces guides you to the final solution.
This will be very interesting test and it looks that we should give some additional effort to make good result on this test.

Regards,
Branko

The Puzzle Booklet has been uploaded.

Please download the Samurai pdf before you start the test. This is not password protected. You can open it and plan how to solve the puzzle.
Our record suggests that many players are just downloading the IB and PB.

Broken Pieces has started. Enjoy the test. All the Best.

Like all other LMI tests, you can view your scores 100 minutes after you start the test.

Although we've taken extra measure to ensure that the answer key is unambiguous, it is possible that some players enter the answer key in a different format. If you find that you have not got points because your answer format is different, you can claim your points here.

Do NOT post your answer here. Just post the puzzle that has been marked wrong.

Of course, if you don't understand any answer key, it is better to get it clarified here before you start the test.

I just finished the test. Great puzzles. I will not put any technical comments until the test is over. My only advice is do participate in this test, you will love solving these puzzles. Thanks Rohan and Tejal for the great set of puzzles.

Do put your comments when you solve this test.

Also be ready with the Samuari Sudoku pieces cut as suggest in the IB. It will be helpful in the test.

Edited by rajeshk 2010-08-28 12:05 PM

Very nice puzzles.Pretty easy too.I made an error submitting Tapa.Entered the contents of 5th column,instead of 4th.hope it will be considered.
It was time-taking without a printer! :)

No, can't consider that :-)
It will set a wrong trend.

Announcement

ZigZag (Puzzle# 12 with 5 points) has 2 solutions.
Full points will be given to players who submit any of the solutions.

Excellent set of puzzles.
Thanks and Congrats to Rohan & Tejal..............

Thanks a lot Rajesh :-)
Thanks Aditya, Neeraj.

Hope the rest of you enjoy the test...

Tejal/Rohan.

Brilliant test. Congrats Rohan and Tejal!

Nice test, Rohan and Tejal. I liked domino hunt and tents.
I made a typing error in the answer for irregular sudoku, but the error is with a digit which is already given in the puzzle. Please check if you can consider.

I've sent mail to Rohan regarding my B&W solution, please check.

Please send to this id too logicmasteradmin@gmail.com

Considering it as correct, since there is given digit where you have made the typo.

Rohan replied to your email. Rotating/Mirroring pieces is not allowed in any of the puzzles. [Page 2 IB, PB]

Thanks a lot everyone! :)

Thank you for this nice contest. I never used my rubber this much :)

Thanks for the puzzle set; adding in the 'broken piece' very innnovative! Cheers, Dave

Lovely set of puzzles.
I liked the logic in Minesweeper, Tents, Hitori and Loop Finder.
I couldnt find the logic for some of the puzzles like Tapa and Black and White and resorted to trail and error for the time bound test.
The Dominos puzzle was pretty nice since the broken pieces get revealed in the very end.
The other puzzles were relatively easy and hence I managed to save some time on those.

Tejal and Rohan, thanks for the wonderful test :)

Fun but simple test. I made my typical boneheaded answer entry mistake (not counting a 90 degree turn in the zigzag that was made out of diagonal lines) but will simply imagine the score I might have had. Thanks Rohan and Tejal.

Rohan&Tejal: Nice test
Logic puzzles were great, but both sudoku puzzles were very easy, I expected something more difficult.
I made answer error too (unfortunately in most valuable puzzle - In Tents puzzle I wrote vertically connected tents in second answer part instead of tents in diagonal) But Tents puzzle has great logic, I like it most (with Tapa puzzle)

Congratulations to Hideaki Jo, Ulrich Voigt, TAKEI Daisuke for topping LMI test Broken Pieces.

Relatively, we've had slightly less participants, may be because of so many other tests this weekend. 75 (out of 92) got non-zero scores.

Thank you everyone.

For puzzle tests, we've had more time than actually needed, so that more players get a chance to solve most puzzles. But we realize that it is not necessarily the best thing to do. In this test, apart from you, there is Sebastin who got Scrabble Loop incorrect. It could be a counting mistake or a genuine mistake while solving, but to lose 5+46 or 32+13 (out of 100) points because of one mistake is really too much penalty, in my opinion.

May be we should have 2 different targets (minutes) for top players and beginners. But I'm not sure how to do the points calculation etc.

I've often thought bonus points should be awarded even in the case of imperfect submissions, according to something like the following rule:

Calculate (Points earned - 5 * points missed) / (Total points), and that is the multiplier used to adjust from the bonus points the solver would have been awarded. Maybe the number in the formula should not be 5, I guess that is up to the organizers.

So for this exam, someone who makes a mistake on the answer submission (or is incapable of solving one of the puzzles) could perhaps go from 100% of the bonus points to (95 - (5*5)) = 70% of the bonus points. I believe the multiplier should be large enough to discourage solvers from skipping puzzles (since skipping a 5-point puzzle will cost you much more than just 5 points) entirely but not so large that the bonus points vanish completely due to one mistake or stumper. I also believe those of us who only solve a bare majority of the puzzles should be denied any bonus points, and this ensures that as well.

But enough about bonus points. This was a fun test and shows the true talent of Rohan and Tejal. Not only can they write sudoku puzzles but also these other varieties -- and entertaining puzzles at that! Thank you for yet another enjoyable test.

@Ziti: Very simple, but interesting idea indeed.

I was tempted to do the calculations based on the formula that you had suggested. Click here for the points with adjusted bonus. [As expected, only motris and Sebastian get significant bonus points ]

I think providing bonus point for these imperfect submissions will be correct. Thumps up from my side.

Would like to understand what others feel about this.

We're glad you all enjoyed the test. Thank you once again! :)
Just a little disappointed with the participation level, but as Deb said, it could be because of 5 other competitions during the same time.

This is not a rare occurrence; I missed The Sampler test but I recall in those results that janoslaw if not others had lots of potential bonus lost to one single mistake. I've made a whole blog posting on my stupid errors that cost me time bonus at WSCs and WPCs (http://motris.livejournal.com/93115.html). We tried to accommodate this contingency at our WSC as it is a lingering issue, but all our rounds were so well-timed that it never became relevant. Our concept was 5 points per minute without errors; 3 points per minute for being functionally done but with a mistake somewhere.

On an internet test though I haven't been as worried. This is because the "time stamp" lets you have everything submitted and then check over your work. On Evergreens, for example, I caught my two entry mistakes in the Hitori and Magnets, so while I sacrificed ~10 minutes of time, I got a clean total paper. Today, though, the answer entry itself failed for me since I was not looking for diagonal 90 degree turns and did not catch the problem on my double-check. Since the IB's count actually had such a case, it's my fault for not spending time to very carefully check the submission rules. Regardless, some contingency for time with mistakes should be allowed.

Unlike ziti's system which is still tied to puzzle value (the solver is losing the "extra" points already if the stupid error is in counting scrabble or entering vertical tents or missing a 90 degree turn), I prefer a fixed "cost" on the time bonus per mistake. At the WSC we were going with 60% but I could see on a test like this something like 11/12 correct = .8 points per minute; 10/12 correct = .6 points/minute; ... or something similar. What's important is that the value of the bonus per minute never overwhelms the value of solving the puzzles so that no solver will be motivated to be "incorrect" once or twice to get fractional bonus instead of just solving all the puzzles. Either ziti's system or mine seems to do this.

Edited by motris 2010-08-30 9:52 AM

The idea is indeed interesting and can be implemented easily. I like it too, but, in my view, it is probably against the spirit of bonus points and makes it trivial. Bonus points (so far) is a kind of reward that is given ONLY if someone manages to solve ALL puzzles correctly (in online tests, unfortunately, the most important aspect of this correctness is accurate answer entry and we have to live with it). With this system, there will likely be a few cases where X, who has solved one puzzle less, gets more points than Y, who has solved all puzzles. And that does not sound right.

There are two cases here:

(1) Mistake in answer submission: The participant should not be given bonus points, because he probably had time to re-check his answers for correctness. It is always an accuracy v/s speed balance. The participant took a risk by going for maximum bonus points. It is perfectly possible that those who have actually got bonus points have checked their answer multiple times before submitting.

(2) Incapable of solving one of the puzzles: The participant should try to solve it in the remaining time rather than try to gain partial points through this mechanism.

Another important aspect which was especially relevant to this test is the concept of penalty for wrong answers. Many of the answers were guessable, and we either need to have penalty points or more complex answer keys (not too complex, but not single digits either).

In fact, I had three puzzles left with one minute left. I submitted dummy answers for the three and got one correct too.There may or may not be others who may have done this as well. And, this should not be allowed.

Very valid point Rakesh. [ While I was testing the submission system on Friday, I entered dummy answers. And when I looked at the score page, I had got 18 ]
I would prefer non-guessable (or difficult-to-guess) answer keys to -ve points.

As rakesh mentions, having answer strings that are "guessable" requires either different choices for the submission or penalties for being wrong or both. Guessing a sudoku row is unlikely (oftentimes approaching 9! options), but guessing "0" in a puzzle that could only take 0,1,2,3,4,5,6 as possible entries, and maybe only 0-3 as likely entries is a problem.

Rakesh, your point is valid.
But players make silly mistakes, and to lose 51 or 43 points (out of 100) because of the silly mistakes is too heavy a penalty.
There are multiple stages to make mistakes
a) player solves incorrectly
b) player solves correctly, but computes the answer key as incorrectly
c) player finds the correct answer key, but types incorrectly (if it is a long answer key)
d) player forgets to click submit button :-)

I would think we should give bonus points (based on one of the formulas suggested above or any other) to players doing b/c type of mistake. [because only b and c type of mistake can happen in online tests like ours]
But to determine whether it is a-type mistake or b/c-type mistake becomes very subjective.
So we should give partial bonus points to players. As long as "value of the bonus per minute" does not exceed "value of solving the puzzle".

I think (b) should be treated like (a) - finding the answer key is (practically) part of the puzzle solving. For (c), if the organisers think it is a typing mistake and is a genuine case - go ahead and award the points for the puzzle; the bonus shall take care of itself.

I agree (b) should be like (a)
Differentiating a typing mistake with a genuine mistake is too subjective. Lets just scrap a/b/c/d.

Either we give partial bonus points based on some formula or we don't.

I am happy that world Champs mind and my mind work in the same manner.............He also did the same mistake as I did in the Zig-zag... LOL

Only 9 participants have rated the puzzles (out of 75 non zero scores)
Should we have some bonus points for rating puzzles also ?

it will be too harsh I guess ...
but we can think about not displaying the detailed scores if someone has not rated the puzzles :-)
OR
Not displaying scores which are higher than that player :-)
OR
encrypting all others players' user ids :-)

Anyway, I think its okay, if players don't rate. We should not force them.

Thank You: Nikola, Rakesh, Semax, Dave, Amit, Thomas, Jason and all participants.

Congrats to Hideaki, Ulrich and Takei!

I'm glad most of you'll enjoyed the test. The test could've been a little shorter (maybe 75-80 minutes as suggested by Deb). The low participation was expected due to other contests.

Apologies for the multiple-solutions Zigzag and the incomplete-instructions Tapa.

See you all at Evergreen 2!

Rohan.

Thanks Rohan/Tejal for this great test. I enjoyed solving all these puzzles. Nice to see more and more people creating puzzles. LMI provides right environment for showcasing not only your puzzles solving talent but also your puzzle creation talent. Three cheers to LMI! Looking forward for more such puzzle tests.

Thanks a lot! I truly agree with you and I'm sure there will be better and more exciting contests by Indians (other than you, Amit, Deb, Rakesh, the regulars...) in future :-)

At LMI online we try to design the test timings in such a way that an average solver is able to solve all (or most of the) puzzles in the test and thereby we expect some of the top solvers to get a time bonus.
Even at offline competitions it is difficult to estimate the correct time for a test given the rate at which sudoku solve timings have reduced over the past couple of years.

It was nice to see a discussion on the loss of bonus points due to small oversights.
In offline competitions we can do away with bonus points by introducing bonus puzzles like we have had in the Indian Sudoku Championships in the past and the WSC in Goa.
However since this is not possible for online competitions we have to devise a way in which participants do not loose a large number of bonus points due to silly submission mistakes.
Both Ziti and motris had similar ideas off giving weighted bonus points depending on the number of puzzles solved incorrectly and the number of puzzle points solved incorrectly.

The puzzle points are always related to the time taken to solve the puzzle, so we will compute the percentage of test completed as the percentage of puzzle points solved. The weights will be based on Ziti's approach and hence all participants solving more then 50 % of the test can expect some bonus points for time saved in the test.

Where can I get IB? The IB File is Broken......
(LMIMT_M201008P_IB ? The file is broken..)

Please check now.

Thanks.