Why hand-made Sudoku?
263 wordsI’ve been involved in the occasional heated debate about why hand-crafted Sudoku puzzles may or may not be superior to computer generated ones, and how the Guardian’s puzzles might contain “almost imperceptible witticisms” per their writeup to accompany the first published puzzle.
Well, here is a justification from various representatives of Nikoli, the Japanese puzzle magazine from which The Guardian licenses its puzzles.
I’m not sure the argument stands up. A computer program could easily apply a few heuristics to weed out unsatisfying puzzles like the example he gives (where solving the puzzle requires one very complex leap of logic, followed by a lot of dreary mechanical filling in). sudokuhints.com demonstrates that a computer program can not only solve Sudoku, but do it by applying similar rules to those a human might use. Analysing the log of rules applied should reveal the difficulty of the puzzle, and the distribution of difficulty throughout the solving process.
A computer program can also enforce various kinds of symmetry (which is one way in which those “almost imperceptible witticisms” tend to manifest themselves).
I doubt these “hand crafted” puzzles are really concocted using pencil and paper in any case. It’s more likely that the authors have their own programs and apply the human touch by concocting new and interesting constraints within which their programs must create puzzles — and no doubt they cherry pick the best ones by testing them out manually.
On a related note — since even the hardest Sudoku puzzles are so easily solved using a computer, aren’t the prize puzzles in newspapers something of a farce?
August 5th, 2005 at 16:48
If you like sudoku I recommend you PrintSudoku.com. I has 6 new sudokus every day ready for printing.
April 14th, 2006 at 16:23
As an inveterate hand-made sudoku compiler, I think the main difference between hand-made and computer-generated puzzles is - put simply - just the fact that you can tell the difference! When designing puzzles, I tend to look for interesting grid patterns if the puzzle allows me to go that way (sometimes it doesn’t - seeds you put in gradually dictate the overall shape). I can, if I wish - and I often do! - try to create a puzzle with as few seeds as possible (my personal best is an 18-seed symmetrical).
In the end, though, it’s down to what the solver prefers, and I think in general solvers have no particular preference. But I’m a crossword compiler too, and I’ve seen software-generated crosswords - they really are pretty awful! It could be argued that far more goes into creating an entertaining crossword than into creating a sudoku puzzle, and that’s probably true. But as a solver, if you know that a puzzle (sudoku, crossword, whatever) has been created by an individual you feel a more personal involvement in the battle of wits it presents.
The sudoku puzzles on my site (5 per day, usually) are hand-made, although I use a brilliant piece of software called Sudoku Assistenten to build them. The process of inserting seeds is just like using pencil and paper, but SA (as we devotees call it!) takes the drudgery out of it by constantly updating the grid with inevitable numbers and cancelled candidates.
I like your comment about prize puzzles. Yes, it is a bit of a farce. Sadly though, it’s no more than marketing. It’s why the prize “viewer questions” you see on TV are so hysterically easy - they just want responses in large numbers to help gauge viewership, interest etc.