Wrong Puzzles? [WSC 2011]

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Wrong Puzzles [WSC 2011].png (74.09 KiB) Viewed 6542 times

The first round of the 2011 WSC featured a booklet of examples similar to the above, where the only thing required of the solver was to mark whether the solution grid was a valid Sudoku solution, or not.

This does not require the solver to place any numbers.

This year was the first year that WSC and WPC were combined into one venue in one week. This kind of thinking outside the box is common place to the WPC, and it is possible that ideas from the WPC have come to influence WSCs more and more since 2011.

[Nilz]

As the only person to vote that this is fair game for a sudoku competition, allow me to put forward my thoughts.
Clearly, it's not a sudoku puzzle, or even a variant. It's a sudoku-related puzzle. I feel that all remotely sudoku-related puzzles should be allowed in the WSC. Conversations on other threads about other examples have (to me at least) seemed to indicate that any attempt to draw a line between which sudoku variants are allowed and which aren't is bound to be arbitrary or hugely subjective (especially when you consider the fact that something completely different may yet be invented which blurs the lines even further). To me, if it 'looks like' a sudoku, it's suitable for a sudoku competition.
I assume that isn't likely to be a popular point of view, although it does have the advantage of simplicity (and 'looks like' could obviously be defined more thoroughly). If you want to find the best sudoku solver, have a few rounds of classics. To include some variants but not others makes no sense to me. This doesn't need to be a two day competition either. If I 'ruled the world', my current thinking is that the World Puzzle week should be organised roughly along the lines of:
-Monday:
World Sudoku Championship, 3 hours max (not necessarily in one go!) of classic Sudokus;
World Tapa Championship, 3 hours max (not necessarily in one go!) of classic Tapas;
World Kakuro Championship, etc
Basically several separate short competitions designed to find the best specialists at each discipline. The exact puzzle types represented could switch around each year, perhaps. Candidates could enter as many or as few as they liked- if they liked the third type but not the second, they could take a few hours off to recharge.
-Tuesday:
As Monday, but variants are allowed. Leeway is given to the designers as to what constitutes a variant. So for example, the puzzle in this thread would be allowed here (and also allowed in a WPC)
-Wednesday-Sunday:
As now- a tour, followed by the WPC, where pretty much anything language neutral goes (possibly you should have at least 30% of 'familiar' puzzles, which is basically an unofficial rule anyway).
Since I don't actually rule the world, I haven't thought out the details thoroughly, but I am interested to read other opinions.
Sorry for hijacking the topic somewhat!

[Fred76]

Neil,
Your post could require a very long answer on all points you raised. I'll not comment about the fact that you want to kill the wsc and replace by competitions about different puzzle types.

About the first part of your post, I think the best way is to answer with a puzzle. Here it is:

neil_sudoku.png (18.12 KiB) Viewed 6487 times

I hope you understand with this particular puzzle that your arguments can't be applied for wsc.

Fred

[berni]

I hope you understand with this particular puzzle that your arguments can't be applied for wsc.

Sorry, but I don't understand what this puzzles has to do with the discussion...

[Fred76]

I hope you understand with this particular puzzle that your arguments can't be applied for wsc.

Sorry, but I don't understand what this puzzles has to do with the discussion...

Did you solve it?

[berni]

Did you solve it?

Yes. I assumed it's a classic sudoku and found out, that it has a unique solution.

[Fred76]

Did you solve it?

Yes. I assumed it's a classic sudoku and found out, that it has a unique solution.

Oops, sorry, this is my fault: I forgot to write the rules .
Rules:
Draw a single, non-intersecting loop that passes through all cells containing a digit. The loop must go straight through the cells with even digits, with a turn in at least one of the cells immediately before/after each even digit. The loop must make a turn in all cells with odd digits, but must go straight in both cells immediately before/after each odd digit.

It's not that hard for a masyu to disguise in sudoku, in order to enter the wsc party, where Neil is the bouncer.

Fred

[Nilz]

Very nice Fred.
Perhaps 'looks like a sudoku and has at least a semblence of sudoku logic' would be better. But then you'd have to define what a 'semblence of sudoku logic' is. To be fair, I did say I haven't thought out the details thoroughly. However, I am very much still in the camp that says lots of leeway should be given to constructors (except maybe not quite that much leeway).

[Fred76]

Perhaps 'looks like a sudoku and has at least a semblence of sudoku logic' would be better.

Neil, I'm sorry but I've still lot of problems with everything you say: the "looks like" create more problems than it solve, I can't understand the "semblence of sudoku logic", I don't understand why some people come to a debate which is supposed to speak about "what is a sudoku" to just say they would prefer that WPF stop to organize sudoku tournament. I don't understand why you said the puzzle of this thread is appropriate, even with use of your arguments.

Ok, first you said:

Clearly, it's not a sudoku puzzle, or even a variant.

Then you said it's appropriate in a sudoku tournament. For me it's total non-sense ! I think you should have said "it's not appropriate to sudoku tournament, but sudoku tournaments are not appropriate to me"

Then:

Conversations on other threads about other examples have (to me at least) seemed to indicate that any attempt to draw a line between which sudoku variants are allowed and which aren't is bound to be arbitrary or hugely subjective (especially when you consider the fact that something completely different may yet be invented which blurs the lines even further). To me, if it 'looks like' a sudoku, it's suitable for a sudoku competition.

If I understand, the fact that it's not easy to stand clear limits justify to you the presence of puzzle that are outside the limits, regardless what the limits are ! I disagree with that. If a puzzle is considered as not being a sudoku, this is ridiculous to allow it in sudoku competition only because we don't have stated clear limits.
Then you come with the argument "looks like" a sudoku, which is much more subjective yet !

I assume that isn't likely to be a popular point of view, although it does have the advantage of simplicity (and 'looks like' could obviously be defined more thoroughly).

If you're looking for simplicity, instead of saying, "if it looks like a sudoku, it's suitable", you can say what everybody here says: "if it is a sudoku, it is suitable". It is even simpler. I don't understand in what adding a "looks like" solve anything.

I've thought a bit more on your argument of "looks like", and to me, the only convincing way to apply it is to allow only classic look-alike sudoku: non-consecutive, antiknight, masyu disguised in sudoku, etc... No, an arrow sudoku without given digit definitely doesn't look like a classic sudoku.
No, the puzzle in this thread doesn't look like a sudoku, it looks like a solution of sudoku, then yes even with your argumentation, it is not appropriate in sudoku competitions.

To include some variants but not others makes no sense to me.

I find this argument very ridiculous ! You really think that if a world sudoku championship doesn't contain a "no four in a grow sudoku" variation it is a non-sense?
Even with strictest rules for sudoku, if we want that every wsc contains at least a puzzle from each of the several hundred variations created so far, the competition could not last only 2 days...
This is totally futile to ask for it !

Perhaps 'looks like a sudoku and has at least a semblence of sudoku logic' would be better.

This is equally ridiculous to me than everything you said before. If you know what the sudoku logic is, you don't have to add the word "semblence" before it. Just say puzzles that have sudoku logic.

If I 'ruled the world', my current thinking is that the World Puzzle week should be organised roughly along the lines of:
...

If I decided to answer you even if in the beginning I thought it would be better to refrain, it's because I think you're not the only one in the puzzle community to have such way of thinking, and the issues concerning wsc are coming from people who think like you.
I ask myself if this is the right think to do to have a debate on sudoku and write the definition of sudoku, if the problem is just that some people don't want sudoku competitions organized by the wpf. Are all issues not coming from the fact that some people just don't want sudoku competitions and make what is in their power to just destroy everything that concerns sudoku in wpf?
Shouldn't we first, before entering the serious discussion about what is a sudoku, have a discussion to know if we really want sudoku competitions at the wpf? (I say "we" but I really don't want to take part in this debate. Either the answer is "yes" and then I'm ready to have serious discussion about sudoku, either the answer is "no" and then perhaps some people would be motivated to not let the sudoku competition die and will found a world sudoku federation).

I entered the discussion just because lot of people say I should do it, but if the discussions turn ridiculously about "do we want sudoku or not at the wpf", I'll stop spending time on that.

Fred

[detuned]

Fred,

Could I ask you to tone down your posts a little. If you are going to forensically dissect, line by line, any opinion which is contrary to yours with comments like "this is ridiculous" then you are going to discourage anyone from offering an opinion at all. And we must definitely not discourage people! I am a little concerned that you are taking any opinion contrary to your own personally.

Neil has offered a point of view which says anything which vaguely looks like Sudoku is fair game for the WSC. He has justified this point of view by saying that trying to draw a line between some variants and others is likely to be arbitrary, and as far as he sees it you may as well have a classics only competition.

That's fine, that's a valid point of view. There is no objectively right or wrong answer about how the WSC should look like - the fact that no two WSCs so far have really looked the same is testament to this. We can only reach a decision and consensus by exploring all the points of view. Maybe you don't agree with some of the points of view, but as I said if you are going to start saying that everything is ridiculous then frankly you are being disrespectful. Instead of trying to objectively prove that any opinion contrary to yours as a logical absurdity, you might be better off trying to understand the point of view.

Neil is a smart guy with interesting things to say, and I'm glad he's contributing to the debate. It doesn't mean you or I or anyone else completely agrees with him, or that that will be the final conclusion of anything, it just means we have different opinions to consider.

[Nilz]

OK so I guess I should've foreseen that shortening the WSC so much would not be too popular amongst some groups of people (note that I didn't suggest killing the WSC altogether, my schedule still has a World Sudoku Championship in). However, I stand by my point that, in the puzzle community, there are lots of other very popular puzzles that could easily have their own championships. I don't think we should necessarily just keep having a World Sudoku Championship and not a World Tapa Championship just because that's what's happened for the last 20 years. Personally, as I've said, I'd quite like to see both, because I don't want to kill the WSC, but they'd necessarily need to be shorter than the existing WSC.
There might be other good reasons to continue to have a (longer than half-a-day) WSudokuC- it's familiar to most people outside the puzzle community, and so that's important if attracting new participants/ sponsors/ media interest is a factor. But this is not really the place to be having that discussion- and we're not really the people to be having it (at least not without others intervening).

The puzzle in this thread is appropriate (in my view) because it requires demonstration of a skill required for solving sudoku- i.e. checking that all the rules of the puzzle are satisfied. When you solve a sudoku, you are, as part of the process, ensuring that all the rules are met (no repeated digits in a row in a classic sudoku, for example)- this puzzle requires demonstration of those skills in a different way, and therefore is sufficiently closely related to 'regular' sudoku solving that it should be allowed. Others are entitled to hold a different opinion. And I agree that as this is only a small part of the sudoku solving process, it's not a good idea for this round to occur frequently or be too long. But as an innovative part of a larger competition, I am in favour.
(Aside: Ability to take a penalty is not a skill that is required to play football, yet top level competitions are decided on who can take penalties the best! I'm not saying this analogy is perfect, but at least I hope you can see where I'm coming from rather than just dismissing my ideas offhand).
If we set a boundary on what's allowed and what isn't there will obviously be puzzles very close to the edge. Someone may tweak the rules very very slightly, create a puzzle that's practically identical, yet falls outside the boundary. That feels nonsensical to me, and that's why it's my belief that setting a firm boundary shouldn't be done- we should either just have a WSC of classics (which could then be much shorter than the current structure, as in my proposed schedule). Or, we should allow a vaguely anything goes approach, and trust the organisers not to include an actual Tapa, since that's clearly not a sudoku (for some definition of the word 'clearly'). I admitted that 'looks like' was not a particularly well thought out definition when I wrote it, I was using it as short-hand for this second approach.

(Also, to clarify, when I said "To include some variants but not others makes no sense to me" I meant "To allow some variants but not others makes no sense to me"- not every variant would need to appear in every competition).

[berni]

+1 for Nilz. You convinced me and I'd like to change my vote, but it looks like I can't do so.

[Fred76]

I would like to apologize for the overuse of word "ridiculous" in my previous post.

There are 2 minimal postulates that I need to take part in this discussion:

1. world sudoku championship should be a sudoku competition.
2. A sudoku competition consists of solving sudoku puzzles.

If one of these 2 postulates is not met, I'm personally not interested in discussions searching consensus and I'm not interested in taking part in wsc.

I'm in the camp that says lots of leeway should be given to constructors too, as long as everybody feel puzzles are appropriate. If someone - inside or outside the puzzle community - think there is an issue (either puzzles are not sudoku, or some sudoku are not appropriate), then an answer should be given. And I'm in the camp that says some previous wsc showed big issues which impacted the ranking unfairly. In the puzzle community, I think there a tradition of fixing issues in a tacit way. Some issues are fixed by next wpc/wsc host, like for example lack of classic sudoku in wsc 2006/2007. It was fixed in 2008 by host, but I think the question about the role of classic sudoku in wsc is still opened and has not been fixed in a long run. wsc showed recurring issues that never have been fixed by the wpf, and we are now in this uncomfortable situation.

The puzzle in this thread is appropriate (in my view) because it requires demonstration of a skill required for solving sudoku

I would agree with you if the discussion would concern the variation "just one cell sudoku"...

When you solve a sudoku, you are, as part of the process, ensuring that all the rules are met (no repeated digits in a row in a classic sudoku, for example)- this puzzle requires demonstration of those skills in a different way, and therefore is sufficiently closely related to 'regular' sudoku solving that it should be allowed.

...but I disagree with this argument here. When I solve a sudoku, the only way for me to solve fast is to not check all rules are met. If there is only one cell possible to place a 6 in a region, I don't check if there is already a 6 in the corresponding rows and columns, or if the 6 could be placed in another cell in these rows/columns. At the end of solving, I don't check my solution, the only thing I check is that all cells are filled. If you are ideally reliable, that is to say you never make mistake when you enter digits, then you don't have to check all rules are met.

(Also, to clarify, when I said "To include some variants but not others makes no sense to me" I meant "To allow some variants but not others makes no sense to me"- not every variant would need to appear in every competition).

I practically agree with you, provided that variants are sudoku. (There are still a few other limits, for example variants that are not cultural - and language-neutral, but I'm sure we can agree with these kind of things).

Fred

[NikolaZ]

If I 'ruled the world', my current thinking is that the World Puzzle week should be organised roughly along the lines of:
-Monday:
World Sudoku Championship, 3 hours max (not necessarily in one go!) of classic Sudokus;
World Tapa Championship, 3 hours max (not necessarily in one go!) of classic Tapas;
World Kakuro Championship, etc

Reorganization of annual puzzle week I see as necessary, just like Neil. I understand that he came to this wondering why the traditional puzzle week in previous years charged with two days of sudoku only. However, I dislike his idea of reducing the WSC on 3 hours, but I want to suggest something else that may be on the trail of a compromise.

For the second year in a row we have Asian Sudoku Championship. Perhaps therein lies the answer - forming sudoku continental championships, which may last even more than two days. I personally, and I believe many others would like to see European Sudoku Championship, which would be organized, say, sometime in the spring. Top 3, 5, 8 or 10 contestants from each continental championship would gain the right to participate in the World Championship that, as Neil presented, could be on Monday during puzzle week.

In this way, a dozen of the best continental competitors through 5-6 sets could fight for the world title. With limited number of competitors the organizers can provide various forms, the group stage, knockout system, survival scheme, everything. Simultaneously, puzzle week would be free for a few more similar competitions, as well as the concept of WPC finally could be in the way it should be, with a lot of sudoku variants too. I suppose that some continental championships may not be held, since we don’t have active representatives in Africa and rarely have them in South America and Australia & Oceania, but it does not diminish the legitimacy of described competition.

At the end a little bit of personal angle. Until WSC and WPC share the same week, with my best willing I’ll not be able to participate in both events because I prefer the WPC and want to preserve the freshness for the last days. I tried several times in past and the fourth day always was my worst. The exception was in India, where the organizers announced that they won’t prepare the finals. I was based at the WSC, which has resulted in an excellent 6th place. After the next three WPC days, 14th place without any preparation is not bad.

[Fred76]

-Monday:
World Sudoku Championship, 3 hours max (not necessarily in one go!) of classic Sudokus;
World Tapa Championship, 3 hours max (not necessarily in one go!) of classic Tapas;
World Kakuro Championship, etc
Basically several separate short competitions designed to find the best specialists at each discipline. The exact puzzle types represented could switch around each year, perhaps. Candidates could enter as many or as few as they liked- if they liked the third type but not the second, they could take a few hours off to recharge.
-Tuesday:
As Monday, but variants are allowed. Leeway is given to the designers as to what constitutes a variant. So for example, the puzzle in this thread would be allowed here (and also allowed in a WPC)
-Wednesday-Sunday:
As now- a tour, followed by the WPC, where pretty much anything language neutral goes (possibly you should have at least 30% of 'familiar' puzzles, which is basically an unofficial rule anyway).
Since I don't actually rule the world, I haven't thought out the details thoroughly, but I am interested to read other opinions.
Sorry for hijacking the topic somewhat!

As we can see by comparing sudoku GP and puzzle GP, the sudoku competitions are constantly more popular than puzzle competitions, despite all efforts are made almost each year to change the format of puzzle GP and to give more awards.
Thus, I don't see for which reason the minimum amount of 2 days competition about sudoku should be removed from the "puzzle week".
It seems to me that your proposal is biased by the fact that sudoku is not amongst your own interests.
What would you say if I propose to you a slightly different thing, integrating some world "puzzle X" championships (because that's the good idea of your proposal):
Monday-Tuesday: WSC - competition containing only sudoku as defined by the commitee.
Thursday-Saturday: WPC, with the specification that thursday is dedicated to 3-4 puzzle type (world "puzzle X" championship).

I'm not quite sure (because I'm not a puzzle player), but I don't see any issue to incorporate world tapa championship or world nurikabe championship in the WPC.

Fred

[Fred76]

If we set a boundary on what's allowed and what isn't there will obviously be puzzles very close to the edge. Someone may tweak the rules very very slightly, create a puzzle that's practically identical, yet falls outside the boundary. That feels nonsensical to me, and that's why it's my belief that setting a firm boundary shouldn't be done

If you think about the opposite situation: you've a puzzle which is outside the boundary, but if you tweak the rules very very slightly, you'll have a puzzle which is allowed by the rules. Why, if the 2 puzzles are practically identical, should it be a problem to chose the one which is inside the rules? For which reason it should be so important to allow the other puzzle, too? What the other puzzle brings if it is practically identical?

I'll explain my thought more precisely on this subject on the thread about puzzle decorations: viewtopic.php?f=33&t=1964
It seems to me that what you don't want to forbid (because it's nonsensical to you) is something that would bring no new interesting things to the solving experience.

Fred

[Nilz]

What would you say if I propose to you a slightly different thing, integrating some world "puzzle X" championships (because that's the good idea of your proposal):
Monday-Tuesday: WSC - competition containing only sudoku as defined by the commitee.
Thursday-Saturday: WPC, with the specification that thursday is dedicated to 3-4 puzzle type (world "puzzle X" championship).

Fred, since I don't actually run the world, it's largely academic what my opinion is on the exact schedule (unless the WPF wishes to have a separate but similar discussion with the community on that topic); however I will say that your suggestion (specifically for the use of Thursday) is an interesting one that would definitely be worthy of consideration if I was in charge!
(Although it wouldn't entirely help, because as others have pointed out, there's no reason why sudoku should be excluded from the WPF and thus could easily appear as one of the puzzles on the Thursday schedule. And if that did happen, someone *may* query why there is also a separate 2 day sudoku championship.)

It seems to me that your proposal is biased by the fact that sudoku is not amongst your own interests.

I'm sure you're right and I apologise for that; if I ever thought my proposal would actually be implemented then before making such a radical change I'd certainly want to hear more pros and cons from both sides, not just the small proportion of people who have taken part in this discussion so far. However, my underlying point is that there are lots of different puzzle types. Most of them do not have a 2 day world championship, and thus sudoku is clearly an outlier in that regard. Whether that's a good thing or a bad thing or a fair thing or an unfair thing can be debated.
I guess in a totally ideal world, there'd be dozens of puzzle types with their own 2 day world championships, and we'd all be professional puzzle solvers earning millions. But that's just a dream.