dailysudoku.com

Marty R. · Posted: Fri Mar 31, 2006 5:45 pm Post subject: Where do you get your puzzles?

I'm looking for a few recommended sites that offer good puzzles (I already use this site). It's not easy to define a "good" puzzle, but it would present a challenge, requiring more than the basic techniques, but not so tough that I couldn't solve them.

For example, I'd like someting that might be a tad easier than the "Daily Nightmare" but a little harder than this site's "Very Hard."

Angel · Joined: 26 Mar 2006 Posts: 31

I use www.sudoku-xls.com/puzzle.html

This is updated weekly (on Saturdays). The puzzles range in difficulty from easy to extra difficult. I only ever do the two hardest (difficult and extra difficult).

These may approach the level you're looking for.

keith · Posted: Sat Apr 01, 2006 4:20 pm Post subject: Difficult puzzles

Marty,

Take a look at Paul's Pages:

http://www.paulspages.co.uk/sudoku/

Here is a nice puzzle from that site:

Marty R. · Posted: Sat Apr 01, 2006 5:56 pm Post subject:

Thanks, I'll look forward to sampling those sites.

keith · Posted: Sat Apr 01, 2006 6:24 pm Post subject: Gone Fishing!

Marty,

After you make a few eliminations, you get to this position, where there is a Swordfish in the rows

and the complementary fish, also a Swordfish, in the columns

Note that each of these eliminates the same possibilities (the values <2> in the red highlighted cells).

After that, there are a number of XY-wings to be found, not all of which are needed to find the solution.

Best wishes,

Keith

Marty R. · Posted: Sat Apr 01, 2006 10:10 pm Post subject:

Keith, as I mentioned, there were triples in box 2 in the original grid. There was also a single "9" in r9. After the eliminations therefrom, I did find a swordfish on the 2s. I don't know if I got to the same position you subsequently showed.

Although I found a couple of XY-Wing patterns, neither could eliminate anything. I then started a forcing chain based in r6c9. Right off the bat, the "4" yielded duplicate numbers, so I solved the cell with the "9" and went on to complete it.

I enjoyed the puzzle. It continues to fascinate me that, although these puzzles have uniques solutions, they certainly don't have unique solving methods. This is just the latest of many examples showing how different people arrive at the same answer by using different techniques.

Victor · Joined: 29 Sep 2005 Posts: 207 Location: NI

This sets me in mind of my (long gone) maths teaching days, when it felt good to let the class go with something that caught them, even if it was off syllabus. To return to Marty R's question . . .

. . . we've all got our own standards & desires. Mine are for sudokus that can be solved using 'logic alone,' which for me means no forcing chains / colour chains, etc., and especially not Nishio. And I like them to be easily printed out for pencil-and-paper soln. Here are my 2 other favourite sites, i.e. as well as this one:-

(1) Sudoku-san's hardest level (atrocious) routinely but not quite always includes X-Wing(s) which makes the puzzles about right for a lazy Irishman who doesn't want the hassle of working with candidate lists. 4 daily puzzles, archived for a fortnight, in a really well-presented website with a nice sense of humour. (Anyone who can publish a sudoku book that uses the letters S-H-I-T-E-D-O-K-U instead of digits has my vote.)

(2) Brainbasher (http://brainbashers.com/sudoku.asp) offers 6 puzzles daily, permanently archived. The 2 hardest levels include most of the 'logical' techniques (much better known to you than me I'm sure). Searching enough for most people.

TKiel · Joined: 22 Feb 2006 Posts: 292 Location: Kalamazoo, MI

Victor,

To say you've got your own standards and desires for solving Sudoku is one thing (which I totally agree with, not being a big fan of forcing chains myself) but when you say you like to do