WPF Sudoku Grand Prix — Indian Round is now over. Password removed from booklet.

Following players are requested to fill in their WPF registration details ASAP. Please check this post on how to do it

1) kimking
2) Manu
3) mjaipal
4) lenzo
5) skrzypl1

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?	A bit hard
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 their point values reflect the difficulty/time spent?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

For some reason in Mozilla Firefox neither the puzzles or even the login part was displayed (not even the initializing bar), so I had to switch to Chromium and there it worked perfectly. Not sure why was that...
Otherwise no problems.

EDIT: Okay, it seems that it might have been because I didn't have the latest version of the Adobe Flash Player as now after updating it's working in Firefox as well. I had 11.5.502.something but not exactly the 149. But in Chromium it still worked using the slightly older version of Flash Player

Edited by driv4r 2013-02-12 9:43 AM

You need to have flash installed for Firefox. Use this link to check - http://helpx.adobe.com/flash-player/kb/find-version-flash-player.ht... if you have it installed.

First of all, I would like to thank WPF for starting this new initiative and Hana for coordinating these events. With online contests growing in last few years, it was a perfect decision for WPF to have its own online competition. The huge number of turnouts at Czech and Indian rounds is an ample proof of that. I sincerely hope the Sudoku Grand Prix is here to stay for a long long time. While the Sudoku Grand Prix was the most logical step to begin with, lets also hope that WPF starts Puzzle Grand Prix sooner than later.

Now in Round2, here are the top 10
Jan Mrozowski, POL 200
Seungjae Kwak, KOR 199
Kota Morinishi, JPN 198
Hideaki Jo, JPN 197
Nikola Zivanovic, SRB 196
Rishi Puri, IND 195
Ce Jin, CHN 194
Vincent Bertrand, BEL 193
Bastien Vial-Jaime, FRA 192
Rohan Rao, IND 191

Here are the top 3, both rounds combined
Jan Mrozowski (399)
Seungjae Kwak (396)
Nikola Zivanovic (392)

Congratulations to the top players and thank you everyone for participating. It is exremely satisfying to see two Indian in top 10 (and one more in top 20) in round 2. Good job Rishi, Rohan and PS. Keep it up.

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?	A bit hard
What did you think about the puzzle quality of the test?	Fairly Nice
Of the puzzles you solved/attempted, how well did their point values reflect the difficulty/time spent?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

Well organized contest with clear forms and instructions; computer interface worked well.

Thanks Deb for the great puzzles.
Thanks to WPF Grand Prix after a long time I started taking part in online competitions. I really enjoyed solving these puzzles.

Hi . I dont know why my score is 0 . I solve some puzzles but in score doesn t any thing . plz help me

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 their point values reflect the difficulty/time spent?	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?	A bit too many puzzles
Of the puzzles you solved/attempted, how well did their point values reflect the difficulty/time spent?	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 their point values reflect the difficulty/time spent?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

It was a really good puzzle set. Maybe it was a bit on the harder side, but that's more suited for me. I'm not much of a sprinter. My favourites were the Odd Even Frame and Odd Even Big Small. But there were a lot of others that I really liked like Renban Groups and Killer. I'd love to hear the logic behind the Linked Classics as the way I solved it involved an assumption, I'm not sure if it holds up.

I understand there's a lot of red ratings for difficulty and time constraint, but newer players have to realise that there's a lot of incredible Sudoku solvers in the world for whom these tests are the right amount of challenging. These tests are to reflect the level presented at World Puzzle Championships. A hard newspaper Sudoku is the basic level for a WSC and variants take practice to get used to. So when you've never really done variants or other logic puzzles running into a test like this might look like an impossible venture. Just keep in mind that the longer you do these the more skillful you'll get. So just try to improve in every subsequent test. It's all supposed to be for fun.

Time for a slightly longish post (after I have recovered from refreshing the score page infinite times)

First of all, thanks to Palmer Mebane and Thomas Snyder who agreed to pre-solve the sudokus in really short notice. Thomas' timings for some sudokus and for the whole set were incredible, but that is not new.

When Amit and me started planning about the test, we decided that the competition should reflect one round at a WSC. We did not want players to finish with huge amount of bonus (also partly because the WPF GP scoring system considers only ranks). The target was top players should finish with few minutes left. That did not happen, but we are happy to see 4 players getting 93% of total score, and several others coming close.

To ensure that it is challenging enough for top players to take around ~115 minutes, we considered two options
a) have as many sudokus as possible, with lot of easy ones
b) have a limited number of sudokus, but many medium tricky puzzles
We chose the later option. I still thought we had many easy sudokus (Classic 1, XV, Odd, Braille). But as voted by many, players were expecting more number of easy puzzles. We probably could not have achieved this without increasing the number of sudokus.

We also didn't want to have many new/unknown types. So many classic / well known types were added and we made sincere effort to make each of them as best as we could do. Really happy to see that those efforts have been noticed.

Before I go into specific sudokus (in next posts), I would like to share my views on the most discussed one - Odd Even Big Small :-)
As an author, I like to give surprises to the contestants. I like unannounced surprises even more. It is interesting that some players who really liked the surprise (at least those who posted in forum) are incredible authors themselves. It is important to note that we had modified the original rules to suit the twist. The only problem was that many players thought their printer is not working properly and is not printing the Japanese characters. I am not sure if that is a valid concern because there were more than one way to check that no Japanese characters were present (e.g. players could have just checked the online solving interface). In the end, only 59 players solved it correctly. That is little less than what I had expected.
Allow me to repeat what some others have mentioned : Players should be ready for surprises. And surprises do not happen all the time.


Well said. Thank you.

I think you are referring to the assumption that a block of 3 rows will get swapped with each other. The puzzle is certainly logical without that assumption - or at least I would think so - but becomes lot easier with that assumption. But like you, I am not sure if that holds up.

So here is the puzzle, with rows of each grid marked for easy reference.



Step 1 :
2 rows can be identified without any solving.
d can only go at s, e can only go at t. Note that these 2 are independent deductions.


Step 2:
After transferring the digits, we can solve upto this stage. [Transferred digits are shaded. Solved digits in red]


Step 3:
Now f can be placed only at r.
[ Side note : so we see that at least one block of 3 rows is swapped among itself.]


Step 4:
Now lot of digits in these 3 rows and middle block of left grid can be determined.


Step 5:
We can now see c = y


Step 6:
Necessary transfers


Step 7:
In box 3 of left grid, we can solve few digits.
Although from the image it looks simple, while solving it is pretty easy to miss.
O stands for Odd, E stands for Even


Step 8:
Again focusing on box3 of left grid.
I will also note that b is either x or z


Step 9:
We also have i=v


That is pretty much a work-in puzzle, with no real cool stuff.

Hey, about step 1: how can e only go to t? Why not y?

Because then R5C1 would have to be 9 in the left grid and you already have a 9 in R4C3 there (e could be in y but y can't be in e). I think that's a big part of what I missed, thinking in both directions.

Edited by Para 2013-02-13 10:44 PM

Thanks Deb. This helped a lot.

If you copy the digits from y to e, you will then have two 9s in same box.

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 their point values reflect the difficulty/time spent?	All puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

Great job on running the tournament. Are there full scores combining Events #1 & 2?

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?	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?	A bit too many puzzles
Of the puzzles you solved/attempted, how well did their point values reflect the difficulty/time spent?	All puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

Oh, now I can see that y can't go to e indeed. But I didn't know that the rows need to be swapped with each other. For example in case of e and y I would think that y could go to any of the rows in the left grid (that it fits into) and doesn't necessarily need to replace e I guess I have misunderstood the rules

EDIT: Just checked the rules again and it doesn't say that the rows need to be swapped with each other! So how was I supposed to know?

Edited by driv4r 2013-02-14 7:44 AM

If row e maps to y, and then row y maps to some other row like a, that means a and e are two identical rows in the same grid. Can that ever happen in Sudoku?

may be u didn't submit yr answer of column abd rows which were marked A B

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 their point values reflect the difficulty/time spent?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

Hello, and thumbs up for the game! Is it possible to have the complete solutions of the different sudokus? Thanks,
Riccared