The New Sudoku Players' Forum

[Murray Whyte]

Hi there

My name is Murray Whyte, and I am a reporter with the Toronto Star, Canada's largest daily newspaper.

I'm writing an article on Sudoku variants, and woudl welcome any forum members' views on the subject.

I'm interested to know why you create/play variants? Are the traditional 9 x 9's just not hard enough anymore for people who have been hard-core players for so long?

And how long have variants been around? I know the Sudoku craze has only been in the last couple of years, but the game has been around for nearly 30. Are variants a relatively new thing, tied to the massive, recent popularity?

Any replies would be gratefully received. Many thanks, MW

[jimbob]

By preference I play killer sudoku. I complete several killers a day from various sources. Ordinary (vanilla) sudoku seems very boring in comparison. If I have free time I will do an ordinary sudoku, I like to do them on paper but without pencil marks. This means that the very hardest ones are not the necessarily the ones I would choose to do.

[Murray Whyte]

Jimbob, what is it about Killer that makes it more entertaining? Is it that much more challenging for you?

Have you been playing a long time? Did you get tired of the 'vanilla' sudoku quickly, or after a long time? Thanks! MW

[motris]

As a competitor at the World Sudoku Championships, which featured lots and lots of variants in addition to the "vanilla" puzzles you mention, I can say that the best puzzlers like being given new challenges that stretch their minds to rethink how to solve them.

In other words, variety is the spice of life. A lot of the joy of puzzling is in discovering the best ways to solve puzzles you have not seen before. Even small changes to a puzzle-type can place you slightly outside of your comfort zone and force you to adapt to the new situation. This challenge - not knowing immediately what you should do, but intuiting it with time - is what makes solving puzzles so enjoyable to me.

Along these lines, sudoku variants are very much new challenges that do not replace classic sudoku but complement it. Jigsaw or toroidal sudoku, for example, make your mind revisualize where the nonets are, as they are no longer just 3x3 squares. New solving techniques, like the Law of Leftovers (LoL), arise which make the variation fresh and exciting as you learn to master them. Killer (sum) sudoku take the puzzle in a different direction, by adding in mathematics to what was really just a logic placement puzzle. Now, being comfortable with handling summations of digits, as seen in killer sudoku as well as in cross-sums/kakuro puzzles, is needed in addition to standard sudoku-solving skills. Greater than/less than sudoku puzzles pose a different mathematical challenge entirely. Other variations, such as the "mechanical sudoku" seen at the World Sudoku Championships, may even have you performing physical manipulations on puzzle pieces to reassemble a grid of squares into a valid sudoku to then solve. Knowing how to solve a sudoku can get you started on any of these challenges, but you need to bring some new ideas to the puzzle as well to be very successful.

Just as you would not likely go your whole life eating just one kind of food, trying out slightly different variations of an old favorite is a great way to spice up your puzzle-solving and keep it interesting.

Thomas Snyder
motris.livejournal.com

[m_b_metcalf]

I'm writing an article on Sudoku variants, and woudl welcome any forum members' views on the subject.

When I wrote my first programs, for 9 x 9, I parametrized them such that they would work for higher values of integer squares. My personal challenge was to publish a 100 x 100 puzzle, which I managed several months ago. Since then, I have reached 144 x 144, but am stopping there as the solver becomes too slow after that to make sensible puzzles.

Regards,

Mike Metcalf

[udosuk]

Basic/traditional/vanilla sudoku is a pure logical game. You can use any symbols to replace the digits 1-9.

Killer sudoku (sum number place), on the other hand requires arithmetical skills. You need to calculate mathematically as well as to reason logically. I find this much more appealing.

[Pyrrhon]

For me the most interesting thing with sudoku variants is also the challenge to find new solving techniques or to adapt old one. How smells a Naked Pair technique in a 2-3-4 sudoku? How interact killer sudoku and jigsaw sudoku puzzle ... But I also create variant puzzles and so there is a second challenge to make a puzzle with the right hardness giving the solver a chance to solve it as well as not making it stupid or uninteresting to solve the variant sudoku puzzle.

Pyrrhon

[Ruud]

When the hype around Rubik's Cube was at it's peak, many variants were produced. The main reason was propably to avoid patent claims by professor Rubik, but they also to gave people some choice and variation.

In sudoku, there are no patent issues AFAIK, but there is some demand in the puzzling community to be able to choose alternatives. At some point, you'll inevitably get that "been there, done that" feeling.

There are a couple of alternatives, when you're in that "been there, done that" phase:

Abandon sudoku altogether

This effectively ends the hype.

Find harder Sudokus

The advanced solving techniques forum and this Eureka forum are full of people who are exploring new solving strategies for the more difficult sudokus.

Find bigger puzzles

Size matters. When you're presented with a 16x16 sudoku, you will see it as an increased challenge. Same with Samurai, Sumo, flower sudoku and my Clueless format. In my opinion, these are not really variants, they are like a puzzle of 5000 pieces vs. a puzzle of 1000 pieces. Just that little extra challenge.

Find alternative puzzles

This is the real territory of variants.

Killer Sudoku is the most widely accepted variant.
Jigsaw (or squiggly, or irregular) sudoku is well known with its "Law of Leftovers" strategy.
Sudoku-X with diagonals is also reasonably popular.
Combination of variations only have a select audience. There are only a handful of people who make Jigsaw Killers, Toroidal killers, Irregular Toroidals, etc.
There is a small community that produces zero killers, zero-X-killers, double killers and all kinds of variations on the killer theme.

Alternative grid types may become popular. I recently introduced hanidoku on a honeycomb grid, which also changes the rules completely. It may take several months before such a variant is known with the general public.

Ruud

[r.e.s.]

Killer Sudoku is the most widely accepted variant.

Relating also to what motris wrote, I can't resist commenting on my aversion to "killers" ...

I don't know how widespread this sentiment is, but adding arithmetic to sudoku is something I find very unpleasant (obviously, many don't agree!) -- so much so that I generally avoid postings with the term "killer" in the title. OTOH, generalising sudoku's units -- e.g. boxes that are irregular regions of adjacent cells or symmetrical regions of non-adjacent cells -- or even variations using hexagonal or other arrays -- preserves what is for me a much-appreciated kind of simple elegance. (To say the elegance is simple is certainly not to say the "solving logic" is necessarily easy.)

Just my two-cents-worth.

[udosuk]

Combination of variations only have a select audience. There are only a handful of people who make Jigsaw Killers, Toroidal killers, Irregular Toroidals, etc.
There is a small community that produces zero killers, zero-X-killers, double killers and all kinds of variations on the killer theme.

I don't think the audience/community is that select/small... It's just that many of these people are more committed to the actual solving then posting and communicating...

On the theme of "combination of variations" I recommend this particular puzzle, which cleverly combines the elements of killer, jigsaw, X and zero...

[lunababy_moonchild]

Killer Sudoku is the most widely accepted variant.

I can't resist commenting on my aversion to "killers" ...

I don't know how widespread this sentiment is, but adding arithmetic to sudoku is something I find very unpleasant (obviously, many don't agree!) --

Actually I agree. The mere thought of that gives me an headache.

----so much so that I generally avoid postings with the term "killer" in the title.

Me too - apart form moderating them that is.

OTOH, generalising sudoku's units -- e.g. boxes that are irregular regions of adjacent cells or symmetrical regions of non-adjacent cells -- or even variations using hexagonal or other arrays -- preserves what is for me a much-appreciated kind of simple elegance. (To say the elegance is simple is certainly not to say the "solving logic" is necessarily easy.)

I think so too.

As for myself, varying the puzzle setter is enough of a challenge for me, although I do like sudokus with an original rare shape, to steal a recent thread name.

I prefer the Classic Sudoku, especially with different symbols (is that a variant?), but the symbols need to be easy enough to write on paper. Not too many of these around!

Luna

[udosuk]

At the end, it resorted to a simple division line: you either love maths or hate maths... I think we need to respect both of these communities... No discrimination please... Peace for all...

[r.e.s.]

At the end, it resorted to a simple division line: you either love maths or hate maths...

I strongly disagree. Although I happen to love mathematics, I also happen not to enjoy mixing arithmetic with sudoku.

[udosuk]

I think many sudoku players also like/love maths. What I mean is in the general population there are people love or hate maths. And it's a similar situation in the sudoku playing world... There are people love or hate to apply their arithmetical ability... Sort of like a microscopic analogy...

It's like some people prefer to drink black coffee, some like to add heavy milk/sugar... You can't say people who mix milk/sugar with coffee are of bad taste...

[r.e.s.]

Nice analogy. Similarly, for some people, whether they enjoy sudoku+arithmetic is less a matter of their "arithmetic ability" and is more a matter of personal aesthetics. (Some people don't like sugar in their coffee, but are adept at happily devouring it in other forms.) AFAICS in this thread, no-one has been disrespectful of others' preferences.