possible typo. The test page says "Consider my score for the LMI puzzle rating". Sholdn't say "for the LMI SUDOKU rating"? is this a sudoku contest or a puzzle contest?

Bad typo :-)
But no changes to interface while the test is running. Will change for the text test

A better version would be
"Consider my score for the LMI ratings"
This would not require frequent changes. Can be implemented after this test is over.

Its a bit of both

Thanks for a very fun test Nikola. I wish I didn't have to travel this weekend (forcing me to wake up at 4:30 AM to compete), but I'm glad I got the chance to see this beautiful, beautiful city to start my journey.

Edited by motris 2011-08-06 8:18 PM

another test full of challenge and fun............I really sometimes wonder if we do not have these monthly LMI tests...how boring will become these weekends.

was a tough test for me !!!!!
I THINK I NEED LOTS OF PRACTISE AND PRACTISE..........
But nice set of sudokus.
Enjoyed a lot whatever i was doing during those 100 min..

Edited by swaroop2011 2011-08-07 6:06 PM

Enjoyable test indeed. Thanks for adding to my weekend.

p.s. What is up with the ever increasing number of folks who are registered and who sign in to take the test and then submit no results? My jaded American mindset is that there may be many folks registering under one name to get the test, solve it, and then return under another name to solve well later. Anything that can be done with additional technology to prevent this, or are we all just on the honor system here? Sorry to drop a mess on the table here, but the fact that so many signed up and didnt enter is disturbing - and its only been increasing.

TheSubro

Edited by thesubro 2011-08-07 6:13 PM

Many other possible reasons to this. Some of these players can simply not have a printer - they get the puzzles, and they will print them or copy them by hand later. Some may not have enough free time to participate; so, again, they get the files now and solve later.
There are also some players who do not want the others to know their score - many consider that they are not skilled enough and are afraid of being ridiculous, while some are skilled and that's the reason why they do not want other top players to know about their strengths and weaknesses. I know such players.
Finally, some are just not interested at speed solving, so they see no interest in sending back answers within a time limit.

Some raw statistics about NonZero scores. Not much significant change over months.
More about this after the test is over.

2010

2011

TestName NonZeroPercent Master Mind Twins 71.11% SPEED SIXES 88.89% EverGreens 76.24% Classic Look-Alikes 79.75% Sampler Platter 88.41% Qixi Festivale Special 72.34% Broken Pieces 81.52% EverGreens II 77.57% Sudoku Hotpot 84.18% Nikoli Selection 2010 82.51% 20/10 Puzzle Decathlon 84.51% Renban Grouped Sudokus 88.83% FLIP 85.22% Screen Test #1 97.34% Puzzles & Chess 71.68% X'Mas Special Sudoku 87.95%

TestName NonZeroPercent Puzzle Jackpot 75.43% Prime Exotica 77.42% Double Delight 76.30% Melon's Puzzle Zoo 71.20% Puzzle Hybrids 76.19% LMI Spring Sudoku Test 73.94% Twist 77.22% LMI April Sudoku Test 77.70% MAYnipulation 71.55% Something is Missing 67.83% Fillomino Fillia 80.79% LOGIDOKU 83.97% Nikoli Selection 2011 77.78% Fivefold Sudoku Test 90.05% Magic Cube 79.31% Sudoku City ??.??%

Ours brun, are you French ???

(Sorry, private joke )

Fred

It is also my case. I get used to start the test and not submit my answers. I really hate rewriting the solved columns/rows, because always make some stupid typos and such mistakes. For me it is not important to be in the results table. I omit the last 5 minutes (the time of possible submiting) and that is how I can still compare my participation with the other contestants

Just like to add my thanks to that of everyone else. An enjoyable end to my weekend.

Thank you Nikola -- these were fun. And I need a new printer! :)

Sudoku City is over. Thanks to all who visited the city. 128 of 199 players got non zero scores.

I'm extremely sad to announce that one of the Sudoku (Inside Skyscraper) didn't have a solution. We are still discussing how to handle the situation.

I'm sure many of you were surprised to read that Inside Skyscraper was not solvable. Left arrow was missing at R9C6. It was such a small mistake, and it almost didn't have much impact on solving the puzzle. para (Bram de Laat) was the person to notice it, and we realized the mistake 3 hours before the test end time. So we decided not to announce it.

However, we realize that some players could have been affected by the mistake, most notably para. So we decide to give full points to para, Semax, jrivet, WaterlooMathie, martin for this puzzle. Their solution is very close to what we expected. motris get 80% because we strongly believe he has a typo in the submission.

Finally, the results - LMI has a new winner this time - Yuhei Kusui who is cleanly ahead of others with 93 points / 11 puzzles. motris and skywalker take 2nd and 3rd position respectively with 10 puzzles each.

Rohan, Rakesh and Neeraj complete the Indian podium.

I got a little sick last night when I heard about a mistake, but I'm fine now. There is a long history of wrong puzzles.

First of all I would like to say a few words about some previous posts.

@ Fred76
Yes, seems it will be a skyscrapers month, but this is coincidence. Sudoku City was originally planned for July, but in June we had Logidoku so it is rescheduled for August. Deb wanted to avoid two consecutive sudoku tests based on logic puzzle types. The reason is that these tests were qualified for UK Sudoku team.

@ rakesh rai
Nice building statistic.

@ motris, neerajmehrotra, swaroop2011, thesubro, Ours brun, puzzlemad, Ziti...
Thank you all for taking the free time this weekend for sudoku and many thanks for the compliments.

Nikola

Now I want to thank everyone who take a walk through our small town this weekend. Congratulation to Yuhei Kusui, Thomas Snyder and Branko Ceranic for topping this test. Yuhei was inaugurated as mayor of Sudoku City.

I must thank to Rishi Puri and Zoltan Horvath, they helped me a lot. I have to mention Rishi’s time. He solved all 12 puzzles in amazing 89 minutes, but in the relaxed atmosphere, so he is only a virtual winner of the contest. The test was planned in two hours, but when I saw his time, I decided to limit the time on 100 minutes.

Once again many thanks to LMI and Deb Mohanty for hosting Sudoku City.

Nikola

Edited by Nikola 2011-08-08 2:25 PM

Nikola, Thanks for building a nice city and allowing everyone to roam around.

I myself was planning to create a Skyscraper based Sudoku test, but your "City Theme" was mind-blowing.

1)
Yes, the number of zero scores are bit disturbing. Close to 35% players have zero scores in this test. It happens when the test puzzles are tough.
As Ours brun posted there could be various reasons for these zero scores. In this test, many good players started but didn't submit.
greenhorn has already posted why he didn't / doesn't submit his score. I'm not sure if LMI ratings has a role to play as well.
Ideas on how to improve non-zero scores is welcome. (It is not surprising that fivefold is the only test with >90% non-zero scores. Players couldn't have waited till the end to decide whether they should submit or not)

2)
Regarding players trying to cheat the system using 2 logins : we can't be too concerned because in my mind there is no technical solution to prevent this when the test is running for 48 hours. However, let me assure all that we do our best to find out such cases, and disqualify. We don't post how we detect such cases and who we disqualify, but previous authors (as recently as Something is Missing, Fivefold) can certify that we've disqualified more than one player in each cases.

I think that P07 should be voided. When I realized in the bottom row that it has no solution, I didn´t post any. I don´t think that giving points for incorrect solutions is good idea.

I was very surprised at the results. I’m very happy to win a LMI contest after an interval of more than two and a half years (Mock Test 3 held on December 2008). One of the main reasons for win is that the points of SUM and PRODUCT were relatively low; I’m poor at mathematics...
Nikola, thank you for the beautiful constructions.
Together with wonderful citizens, I’ll do my best for the development of Sudoku City!
(At first, I didn’t plan to participate in the skyscrapers contest in Logic Masters. But I decided to visit that contest as "official duty" )

BTW, I’d like to point out one thing. When I solved 11 grids, there were about 5 minutes left. If I had been a completely rational man, I had hit “Claim Bonus” button immediately and got additional 2 points. (In fact, I felt it was almost impossible for me to solve a 7-point PRODUCT in 5 minutes.) But I hated to abandon a puzzle and selected to try last one, only to lose time bonus points.
We should avoid “Quit early, Get advantage” system, which is a lesson we must learn from Zilina. Thus I think some consideration is needed for putting together partial-solved time bonus system and “Claim Bonus” button.

Anyway, the next puzzle test is designed by the Japanese puzzle makers. I hope many people can enjoy our high-quality puzzles!

Edited by Yuhei Kusui 2011-08-09 8:29 AM

Congratulations once again for winning. Even Branko is in the LMI podium after a long time.
I find it interesting to see new winners, although motris is always a favorite to win every test he plays having won 7 of the 11 Sudoku tests he has played.

The "Claim Bonus" button is new, and the functionality probably needs few refinements.
But, I'm guessing that you suggest we shouldn't have had partial bonus points in this test.

Our partial bonus system in WSC Philadelphia was tied to a belief that the solver had made an honest effort on any puzzle they had a mistake in. They might have lost the puzzle points for a mistake, but they had spent enough time to get far enough on it. I would certainly lean in this direction. I still think the best system for an online test uses some amount of instant grading and reporting at the moment of claimed bonus which might tell solvers with a typo that they have 1 puzzle wrong and would tell solvers that are done that they are done. No blank (early quitting) submissions would ever make sense in this system but at the same time typos wouldn't void all possible time bonus.

The way "Claim Bonus" was designed would have required Yuhei to enter solutions for all 12 Sudokus. So in effect, the bonus points would have been only if all 12 are correct, OR 11 are correct + 1 is incorrect. However, there is nothing that would have stopped one to enter some dummy answers for the 12^th to claim bonus.

With instant grading not in place yet, one change we could do is authors/organizers can decide whether the wrong answer is an genuine attempt and give bonus points accordingly.