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Puzzle difficulty

First of all, I posted a Killer X puzzle rated THINKER for today. I would like to know how difficult you find this one. Regarding the INSANE puzzle posted on Friday – I see that there has been a lot of discussion regarding it’s difficulty and the difficulty of some other puzzles posted last week. At the moment I’m rating puzzles depending on the number of different solving techniques that must be used, their relative difficulty (cage splitting is rated most difficult) and the number of times you must use each technique to solve the puzzle. For instance, the EASY puzzle posted on October 27 required only “innies/outies” and basic classic Sudoku techniques. Now, some “innies” are sometimes difficult to spot at a first glance, but it’s a basic technique which experienced solvers should’ve mastered by now. On the other hand, in addition to “innies/outies” the INSANE required cage splitting and some advanced Sudoku techniques (match/hidden subsets). I will have another look at rating puzzle difficulties and see if I can improve it. Perhaps I should rate “cage sums” more difficult for big cages (applying different combinations of possible cage sums). Whatever the difficulty, I hope you are enjoying solving the puzzles. Difficulty is a somewhat personal issue – it depends a lot on which techniques you’ve mastered and which ones you’re still learning. We’re still doing fine on the Top 50 Sudoku list. And we’re still the only site there posting daily Killer Sudokus (a couple of sites that claim they have Killers are actually just linking to us).
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  1. cindy_spain
    Posted October 31, 2005 at 2:41 pm | Permalink

    Today’s puzzle was quite easy, actually. I just guess we’re becoming real experts!!!

  2. Steve C
    Posted October 31, 2005 at 4:17 pm | Permalink

    No great problems with today (although I did mess it up once), a consequence of not concentrating and doing it at work!!

  3. girlwithglasses
    Posted November 4, 2005 at 4:59 pm | Permalink

    Like a number of the other posters here, I didn’t find the “insane” puzzle difficult – I think the previous day’s puzzle took me longer to complete! Perhaps you should solve the puzzles yourself the day before and give them a rating based on how long it took you to do them? It must be possible to calculate mathematically (or semi-mathematically) how “difficult” a puzzle is, but I think the formula for calculating difficulty needs to be more complex than the current one. Perhaps something to do with how many possibilities there are for each cell? Hmmmm.

    As a side note, I don’t know about other users, but I don’t find the rating system very intuitive – apart from “easy” and “insane”, it’s not immediately obvious what the difficulty represents – e.g. is brain harder than IQ? And where does thinker fit in? Perhaps another scheme could be used?

    Keep up the excellent work with the puzzles, anyway!

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