This test contains a lot of sudoku types of which I didn't make a puzzle earlier.
For that reason the list of links to extra practise material is not so long as usual for my tests.

Non Consecutive Killer: very easy; easy
Odd-Even-Big-Small easy; average (scattered grid)
Chaos Renban easy
Rhombus Sudoku average
Scattered Sudoka average

In the coming days I will publish some more practise puzzles (other types than above) in the portal of Logic Masters Germany. I will keep you all informed about it.

Meanwhile the first leftover puzzle appeared:
Give me five: average

Could anyone explain between sudoku ? Not being able to understand

the rule is applicable on given clues.and that too if in any row or column there are two or more clues given.
Considering IB example: In c1 clues given are "9_6" so between 9 and 6 only 7 or 8 can come. Now consider c5, Between 6 and 1 only 2,3,4 or 5 can come. and between 1 and 9 of course any digit. Hope this clears your doubt :)

Also, see this post - http://logicmastersindia.com/forum/forums/thread-view.asp?pid=788 , in CLA's thread.

Edited by debmohanty 2013-12-08 8:57 AM

Thanks a lot swaroop and deb

Hi Richard,

The Missing Arrow example has a digit missing: R1C6 is given as 7 in the original test's IB.

I still solved it. Although it took quite some time

You are both right. It is still solvable, but considerable harder. I will adjust the IB.



Is this better: ... digits in these cells must have a value between the values of the given digits. ?

Is online solving enabled for this test?

Also the second and third leftover puzzles appeared:
Sundoku: too hard for BoS
Between Sudoku: average

Enjoy!

Today number 4 was published.
Odd/Even Skyscraper Sudoku: average

Yesterday's puzzle was the second official puzzle in the Sudoku Variants Series: No Touch Sudoku
You can find more about the Series here

Have fun!

I have a question on the Relay Sudoku, just to be sure. Can I be sure that the first puzzle has a unique solution without pulling back informations from the second grid?

Does the Sudoku XV in the IB have 2 solutions? I have a different solution and I don't see any mistakes in it.

Yes, the first puzzle has a unique solution without information from the second puzzle.

In your different solution, have you taken into account that there must be a specified number of corresponding digits per row in both grids on the same page?

Of course the XV has multiple solutions on it's own (without the grid to the left). You can see that even without solving. In a unique XV at least one of the givens has to be a 1,4,6 or 9. Otherwise you could use a permutation (1,4,6,9)->(9,6,4,1) to create another solution.

Edited by Realshaggy 2013-12-13 3:22 PM

The last two practice puzzles are online:
Sudoku XV: easy
Missing Arrow Sudoku: easy

Have fun with these last two appetizers!
I wish all participants a fun and pleasant test. Good luck to all!

Since this is not yet answered, does this mean online solving will not be available?

can anyone explain me Rules of Greater or lesser sudoku ?

Right, we are not having online solving this time. I was hoping to get it done this week, but tied up with many other things to focus on online solving (which needed a minor change in the interface because of IG)

Only one of the rules is true. It is part of solving to figure out the correct rule. See Sudoku A or B IB for more details.

so it means that only the two cells where clue is given in center are of importance. And then the clue is either greater or smaller than other digit that will be part of those two cells ?

The number in the clue is greater than the other cell for ALL given clues

OR

The number in the clue is smaller than the other cell for ALL given clues

In practice material Scattered Sudoku. After entering 5 at R2C5, 2 at R8C9 , non of the colored cells can contain 2?

Thanks got it Deb and Rakesh :)

hie
i think entering 5 at r2c5 itself is a wrong step , in that row 5 can be at r2c8 :)

How balanced do you think the puzzle types of this test were?	Fairly balanced
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
How did you feel about the length / time limit for this test?	Just right
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little
What was your opinion of the booklet formatting and printing?	Just right

How balanced do you think the puzzle types of this test were?	Perfectly balanced
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
How did you feel about the length / time limit for this test?	A bit too few puzzles
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

How balanced do you think the puzzle types of this test were?	Perfectly balanced
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
How did you feel about the length / time limit for this test?	Just right
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little
What was your opinion of the booklet formatting and printing?	Just right

Bram28 - 2013-12-13 9:55 AM

Does the Sudoku XV in the IB have 2 solutions? I have a different solution and I don't see any mistakes in it.


In your different solution, have you taken into account that there must be a specified number of corresponding digits per row in both grids on the same page?


Ah! No, I had not. I am notoriously bad at reading the full instructions ... even as I wondered what those numbers in the middle were doing there ...

Edited by Bram28 2013-12-14 8:39 PM

How balanced do you think the puzzle types of this test were?	Perfectly balanced
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
How did you feel about the length / time limit for this test?	A bit too many puzzles
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

Thanks for the nice test Richard!

How balanced do you think the puzzle types of this test were?	Fairly balanced
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
How did you feel about the length / time limit for this test?	Just right
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little
What was your opinion of the booklet formatting and printing?	Just right

How balanced do you think the puzzle types of this test were?	Fairly balanced
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
How did you feel about the length / time limit for this test?	Way too many puzzles (too little time)
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

How balanced do you think the puzzle types of this test were?	Fairly balanced
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
How did you feel about the length / time limit for this test?	Way too many puzzles (too little time)
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	I have a different complaint

This time unfriendly contest for players without printers.

Edited by An LMI player 2013-12-15 10:04 PM

How balanced do you think the puzzle types of this test were?	Perfectly balanced
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
How did you feel about the length / time limit for this test?	Just right
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little
What was your opinion of the booklet formatting and printing?	Just right

How balanced do you think the puzzle types of this test were?	Perfectly balanced
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
How did you feel about the length / time limit for this test?	Way too many puzzles (too little time)
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Too few pages / too small grids

I attempted the chaos renban only after the test...and found it to be easier than some puzzles worth 30-40 points. I know it can vary with individual strengths, but that's a hell of a lot of variation!

I agree. The chaos renban took me 10 minutes, while the other 100 pointer, x is alive took me 20. There's a few others that I think are incorrectly valued too, but the chaos renban is probably the biggest sore thumb I saw.

How balanced do you think the puzzle types of this test were?	Fairly balanced
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
How did you feel about the length / time limit for this test?	Just right
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

Points distribution is mostly a very hard part of writing a test. I am lucky to have a small team of testers, who are all well experienced sudoku solvers. There is quite some variation between their timings, so I understand the responses here. Especially the Chaos Renban puzzle has a shortcut that makes it easier solvable; the 5's play a crucial role in all five renban groups. Noticing that makes the solving process a lot faster.

It is always worth looking to high pointers in a test, even if you are not among top solvers. It might be better to look at puzzles that you are good at, no matter how much points they are worth.

How balanced do you think the puzzle types of this test were?	Perfectly balanced
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
How did you feel about the length / time limit for this test?	Just right
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

How balanced do you think the puzzle types of this test were?	Perfectly balanced
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
How did you feel about the length / time limit for this test?	Just right
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

These tests are always made to be printed. Puzzling is in general a paper and pencil activity (although I admit some of that is changing). So being without a printer will always make it a bit harder to solve. I don't exactly see what makes it unfriendly though. It might take a little bit more time writing in paint, but I don't see how that can be changed fairly. I for example aren't very skillful in online applets, so that would not give me any advantage if those were made. But I generally feel that some people get a distinct advantage of solving in an online applet as they employ a solving style that would be very impractical on paper.

I personally don't have a properly functioning printer right now. So I did it without a printer in paint. I thought it went pretty well. I would have probably done better with one as it's much easier to write and keep notes and write quickly on paper than in paint. But the grids were easily copy-pasted into paint two at a time because of the layout, so it saved some time in having to copy paste all grids separately. I could solve 2 puzzles and then put in the answer keys 2 at a time, saving me some time in having to switch windows a lot. I did last week's test in paint as well and I thought this one was much friendlier in having to solve in paint.

Edited by Para 2013-12-16 10:09 AM

How balanced do you think the puzzle types of this test were?	Fairly balanced
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
How did you feel about the length / time limit for this test?	A bit too many puzzles
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	I have a different complaint

The only complaint is that there wasn't online solving. It is unconvience for people without printer.

How balanced do you think the puzzle types of this test were?	A bit skewed
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
How did you feel about the length / time limit for this test?	Just right
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little
What was your opinion of the booklet formatting and printing?	Just right

A bit too much math types/sum restrictions.

Edited by Realshaggy 2013-12-16 4:23 PM

How balanced do you think the puzzle types of this test were?	Perfectly balanced
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
How did you feel about the length / time limit for this test?	Way too many puzzles (too little time)
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

How balanced do you think the puzzle types of this test were?	Fairly balanced
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
How did you feel about the length / time limit for this test?	Just right
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

How balanced do you think the puzzle types of this test were?	Perfectly balanced
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
How did you feel about the length / time limit for this test?	Way too many puzzles (too little time)
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

How balanced do you think the puzzle types of this test were?	Perfectly balanced
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
How did you feel about the length / time limit for this test?	A bit too many puzzles
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

How balanced do you think the puzzle types of this test were?	Perfectly balanced
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
How did you feel about the length / time limit for this test?	Just right
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

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
How did you feel about the length / time limit for this test?	A bit too many puzzles
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little
What was your opinion of the booklet formatting and printing?	Just right

How balanced do you think the puzzle types of this test were?	Fairly balanced
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
How did you feel about the length / time limit for this test?	Just right
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

Best of LMI sudoku tests is over. Password removed from booklet.

The bonus shown in score page is wrong (it shows 10 points per minute saved). Here are the correct numbers.

Player	Claim	TotalScore
janoslaw	092:27	1298
TiiT	098:09	1222.62
Ours brun	102:41	1168.64
sinchai4547	113:04	1061.32
kwaka	114:05	1051.86
deu	114:46	1045.6
misko	115:11	1041.82
Kota	116:26	1030.63

BoS is now over. Congratulations to Jan, Tiit and Bastien for incredible performances!

Jan has beaten my estimated winning time with 5 minutes; I expected the winning time to be close to 100 minutes, so I was happy to see Tiit doing exactly this on saturday afternoon. I was a little bit surprised that his time was beaten by 5 minutes by Jan. Well done!

I am happy to see a lot of participants again, and to notice that you all enjoyed it. Thanks for participation and feed back!

I will write something about the test, puzzle choice and few remarks about solving issues on particular puzzles in the next days.

Richard

How balanced do you think the puzzle types of this test were?	Perfectly balanced
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
How did you feel about the length / time limit for this test?	Just right
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

How balanced do you think the puzzle types of this test were?	Fairly balanced
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
How did you feel about the length / time limit for this test?	Just right
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

I am a bit short in time to enter the details, but thanks for a very nice test Richard. I was also a bit surprised by the difficulty of some puzzles said to be hard but such a thing happens on about every test, including mine. I really don't think it is possible to make everyone agree on the point value of a puzzle. And anyway, in my case it was rather a pleasant surprise to see that I was able to solve the Number X in around five and a half minutes. ;)

Congrats to Jan, Tiit and the hungry opponents and thanks again for these much enjoyable puzzles.

Also, I have nothing to complain about regarding the balance of types. Just realized I had failed selecting the "Perfectly balanced" option for this criteria.

Congratulations to Jan and Bastien. I was also very surprised to see Jan's result. After completing the test and seeing others results I was pretty sure that even if I won't win, I should not loose much to the best ones. On the other hand - as the difference between the followers are much bigger than 5 minutes (except Bastien), the 5 minutes (5 and a half minutes to be exact) with Jan isn't so big any more. Anyway I'm very happy to be in this position right now :)

P.S. The top 10 in LMI Sudoku Ratings is quite familiar now - exactly the same as in GP, but just in different order. It makes sense because many GP rounds were held in LMI and this was the base of making this top10, but the list wasn't the same before the Best of LMI sudoku tests.

TiiT

I noticed that you submitted 19 solutions first, without 'X'. When you entered that one few minutes later, I thought you must halve solved already half of the grid earlier, only to finish it after the first lot.
Incredible if you did the complete puzzle that fast.
It has a very narrow solving path, with many different solving steps. In my opinion it was the only real hard puzzle, since it has no shortcuts like the renban-puzzle.
So: Well done!

As you will know, I started my SVS (Sudoku Variants Series) earlier this month. You can read about it here .

The quote above is from the SVS-forum thread. The other project were I was talking about was Best Of Sudokus. Going throug all the Sudoku Tests of 2010 and 2011 was very interesting and fun to do. I found a lot of types that where new(ish) to me and it was indeed one of the reasons I started thinking about SVS.
Since there were 18 tests to be taken into account (with two of them having interacting grids), BoS would contain 20 sudokus. Quite a lot for a test of 120 minutes. So fortunately I could create a few grids of 6x6 to keep the total needed time for top solvers well under the limit of two hours.

Some notes to some of the puzzles then:

Chaos Renban
I like it to include a puzzle that can be solved by all puzzlers in a normal time, but it contains a few shortcuts for top solvers. This one was a good example. Law of leftovers requires that a 5 has to be placed in R34C5. Renban groups with 5 or more cells always require a 5 too, so R4C5 = 5. None of the renban groups in the corners can have the 5 in the center cell; it would block all possible positions of the 5 in the renban group in the opposite corner. Noticing one or both of these shortcuts makes the solving much faster. While I was watching the performances of players, it was clear to me that not everyone found these shortcuts.

Sundoku
The intrinsic logic in the sundoku of LMI Spring Sudoku Test was really brilliant! I had to smile when I recognised it myself. For that reason I thought it would be a good idea to place the sun in a corner cell of the middle block in the test and use the center cell in the Leftover Puzzle. When you didn’t find the logic yet: Digits 1,2,3 in the center block have to go in the sun and both ‘Non-ray-cells’. This means that the 4 can only go in the diagonal ray. If it goes in the horizontal or vertical ray, it would block all possibilities in the sun. So the start of this puzzle is placing 1,2,3,4 in the diagonal ray immediately.

Scattered Sudoku
Using grey cells that are locked in in a white irregular shape is always nice from an aesthetic point of view. I like to do that now and then. But maybe the shape of the regions has scared some people off, because it is the least submitted puzzle. Anyway, Law of leftovers is your best friend in this one: R3567C4 must contain the same digits as R1C1, R2C2, R8C2 and R9C1. This works on the left, right, top and bottom of the grid. No other tricks are necessary.

Number X is alive
This type was high on my list to become the hardest puzzle. Here are the first steps in the solving process: adding the sums of both cages in block 2 leads to an even sum, so the remaining cell has to be odd, and therefor must be 9. The sum of the two cages must be 36 so X is either 3 or 8. If you try X=8, R4C1 = 6 and that is not possible. So X = 3. Now R4C159 can be calculated and filled and R6 can be filled for a lot of cells too.
Later in the solving process R9C28 as (possible) sum and R7C37 play an important role in finishing this one.

Missing Arrows
In Crazy Arrows this one was my favorite (after the test!) but it was not solved that often during the test because it was a real tough one. So I wanted to create an easier one of this type.

I think most of the other puzzles don’t require additional info on solving process, but if you have any question regarding one of the test puzzles, or other feed back; don’t hesitate to write it here in the forum!

At this place I would like thank all authors of LMI-sudoku tests for their inspiring work!

Thank you all for participating; hope to see you all again next time.

I had the Number X out pretty fast too. I agree it's narrow though. Just more of a strength/weakness thing. I took longer on the Sundoku where I missed obvious steps repeatedly.

Oh and also the Blackout Sum, which I broke twice and was the main reason for not being able to finish. After the test, a day later, it was really easy to solve as the points suggested

In No X is alive, author has given the clue that the sums of both cages in block 2 must be even. why? How to manipulate that?
Could you please explain? When the remaining cell can be 2,4,6,8 or 9 how do you choose 9?

It is really easy, actually.

1) We know that the values of these two cages end with the same digit; hence they are both even or both odd.
2) The sum of two even numbers is even. The sum of two odd numbers is also even. So, whatever may be the value of X, the sum of the values of these two cages is even.
3) The sum of the digits from 1 to 9 is equal to 45; so, the value of R2C5 is equal to 45 minus an even number; hence, an odd number; hence, 9.

I hope it is clear enough.

Bastien

First, the idea that the sum of the two cages in block 2 (top, center 3x3 region) must be even:
Note that it is not that each individual cage total must be even, just that their sum is even. They both
end with the same digit ("X"), so their sum is even.

Those two cages are everything in block 2 except the center square, and the sum of all digits in a block is 45. Thus
the remaining digit must be odd (45 minus some even number).

The remaining digit must be 9 since we know it is odd, and 1,3,5 and 7 are all eliminated by the placement of those
digits in the same row/column of the one we're looking for.

It is very clear now. Rest of the things I completed.
Thank you very much for your immediate response.