The New Sudoku Players' Forum

[Janice]

Hi, I’m new to Su Doku. I understand how to find the logical solutions (such as are on this sites “Tips” section) and have not problem with the easer puzzles. But, I’m a little confused about the concept of have to guess once getting to a point in the harder puzzles in which there are no more logical steps (or I am just overlooking steps). Guessing, or assuming, a number almost seems like cheating. Is this just the way the game is? Or is it possible to solve the more difficult puzzles without guessing or assuming any numbers, and I just don’t know those steps yet???? Any clarification, or information on tricks to solving the more complex puzzles would be appreciated.

Thanks, Janice

[PaulIQ164]

If you're doing Pappocom puzzles (from the computer program on this website or one of the newspapers that carries them such as The Times), then you shouldn't have to guess, and there must be some logical techniques you're yet to discover. In fact, this is very likely the case wherever you're getting puzzles from. There are puzzles, however, where you would need to guess eventually, but you should try to avoid these if you don't like the idea of solving by trial and error (as most people don't).

[zebedeezbd]

Or is it possible to solve the more difficult puzzles without guessing or assuming any numbers, and I just don’t know those steps yet???? Any clarification, or information on tricks to solving the more complex puzzles would be appreciated.

Hi Janice,
Some of the logical techniques required for cracking tougher puzzles include naked doubles, naked triples, x-wing, and swordfish. This is not the place to go into exactly how these work, as the techniques are discussed extensively elsewhere. Suffice to say, with these techniques under your belt (in tandem with the more trivial techniques that you have no doubt discovered yourself already) it will be a very tough sudoku indeed that cannot be solved.
PaulIQ164 is right though, some newspapers (etc) do produce puzzles that actually require some guesswork to be solved. I think I speak for the majority in this forum in saying these tend to be frowned upon as inferior, but there are some people who like that type of puzzle.

[emm]

Aha, there’s life in the old dog yet - I love this topic! I love how it keeps rolling over and how I just can’t resist giving it a kick every time it twitches.

For me, forcing chains are logical guesses that straddle the bridge between logic and T&E and I believe they can be found in very superior puzzles, not the kind we frown on at all! Actually, they’re damn difficult to find in any puzzles, as far as I can tell, but that’s beside the point. The point is it’s all a bit of a murky grey out there in the middle distance and in the end we're all just fumbling around in an illusory labyrinth of logic, aren't we? (Poetic licence - arguably invalid.)

[lunababy_moonchild]

Hi, Janice and welcome to the Forum (and Sudoku).

As previously stated, depending on personal preference, guessing need not be necessary (although I respect the wishes of those that enjoy that particular game). Pappocom and Nikoli puzzles do not require guessing and can be solved by logic alone - so they maintain. Although, as you can see from this thread, what constitutes logic is a matter of contention too!

You don't say what level of solving you've attained, other than past easy, and you don't say whose puzzles you are solving. I can say with complete confidence (because I asked Wayne myself) that Pappocom puzzles do not need anything more advanced than x-wings and then only for the very hard puzzles.

Perhaps you could tell us whose puzzles you're solving and whereabouts past easy you've gotten.

Luna

[Cec]

Hi Janice, You say you're new to Sudoku and have requested information to solving the more complex puzzles. The following websites may be of benefit to you:

(a) http://www.angusj.com/sudoku/hints.php
(b) http://www.simes.clara.co.uk/programs/sudokutechnique

Regards Bonsai Cec

[emm]

I think La Luna and Bonsai Cec could quite possibly be the two politest people on the planet!

[Cec]

Thanks em for your comment. I'm not always polite as recently revealed when Flintoff was bowling.
Bonsai Cec

[lunababy_moonchild]

Thanks Em.

Luna

[simes]

The correct link ishttp://www.sadmansoftware.com/sudoku/techniques.htm

(Edit: updated URL)

Simes

[l$]

Hi Janice,
I started solving Sudoku puzzles a few months ago and although I've been reading the posts on this forum, this is the first time I've posted. I agree with the posts, that most of the puzzles in the various newpapers, while not always easy, can be solved with, at most, knowledge of X-wings. BUT--go to the sites proposed by CEC and you'll have some fun trying out the puzzles furnished with the various tutorials!! In particular, the swordfish and forcing chains tutorials provide some nice, challenging entertainment. All can be solved without trial and error. Right now I'm working the Nishio and Couloring puzzles from the simes.clara site to see if those two techniques are truly required to solve those puzzles. Good luck and let us know how you fare.****1$

[Cec]

[url=http://www.simes.clara.co.uk/programs/sudokutechniques.htm[/url]]http://www.simes.clara.co.uk/programs/sudokutechniques.htm[/url][/url]

Simes[/quote]

Oops! Thanks for the correction Simes - sorry about that Janice.
Bonsai Cec