Logic or guesswork?

Advanced methods and approaches for solving Sudoku puzzles

Logic or guesswork?

Postby Karyobin » Mon Jun 20, 2005 4:51 pm

I know I'm going to place the proverbial feline amongst the flying rats here, but I must confess to being somewhat disappointed at my recent discovery (on this forum, no less) that some Very Hard sudoku cannot be solved without resorting to trial and error techniques. Whilst I am fully cognisant of the argument that trial and error is merely an extension of logical reason, I feel forced to point out that trial and error is barely more logically reasoning than tying your granny up, throwing her in a river, seeing whether or not she floats and thus determining her degree of dedication to the dark arts.

I jest of course, but seriously: for me the beauty (and compulsion) of sudoku lies in pitting one's wits, powers of concentration and mental agility against the puzzle. None of these qualities are required in the exercising of trial and error. Admittedly, it is first required to enter all possible candidates, and then to reduce these as far as possible via the tenacious application of the excellent techniques described in this site and others (forget about the long-windedness Angus, you write whatever you like mate, I do). But when does one resort to trial and error (let's face it, we could re-phrase that query as 'when does one give up)?

However much we dress it up in pseudo-mathematical/computer jargon (IF...THEN...ELSE's and suchlike) - trial and error is linear, logical reasoning is lateral. Sudoku attracts us because of its lateral nature. When we hit upon a stumbling block, we sit and gaze until we think our way through it. The sense of satisfaction to be drawn from overcoming such a stage is almost disturbingly palpable. There is, to my mind, no such satisfaction to be drawn from trial and error, for what use is a solution if you don't know why it is a solution?

I shall continue to solve sudoku, but from now on I may spend more time on Hard ones. I'll try to get my times consistently beneath eight minutes because, ultimately, I'd rather improve my analysis and pattern recognition skills than run the risk of spending another four days trying to fight an unbeatable foe.
Posts: 396
Joined: 18 June 2005

Postby Animator » Mon Jun 20, 2005 4:58 pm

Well, all Pappocom puzzle guarantee a unique logical solution.

If you are refering to the 'Very Hard' category of the Pappocom puzzle's then your statement is incorrect. All of these are solvable without Trial and Error.

But, there are other sudoku creators out there, and some of these puzzle require Trial and Error.

Bottom line: if you limit yourself to only Pappocom puzzles then you will never need Trial And Error.

If you need a list of papers that publish Pappocom puzzles then you can look at the main website under solutions... (Or in the 'Sudoku: in papers and publications' section of this forum)
Posts: 469
Joined: 08 April 2005

Postby Karyobin » Mon Jun 20, 2005 4:59 pm

Marvellous stuff, that's good to know. Pappocom for me from now on.
Posts: 396
Joined: 18 June 2005

Postby scrose » Mon Jun 20, 2005 6:54 pm

For the sake of completeness -- I'm certainly not trying to steer anyone away from Pappocom -- Nikoli puzzles also never require trial-and-error (except for one noted by Wayne). The Guardian publishes Nikoli puzzles. The only other source I know of is directly from Nikoli themselves.
Posts: 322
Joined: 31 May 2005

Postby lunababy_moonchild » Mon Jun 20, 2005 9:20 pm

The available-only-in-WHSmith magazine has puzzles hand-created by Nikoli.

Good luck getting it though!

Posts: 659
Joined: 23 March 2005

Return to Advanced solving techniques