The New Sudoku Players' Forum

[giant]

Where do I find VERY difficult sudocus demanding different tactics (except for guessing)? Preferably, but not necessary, symmetric puzzles.

[angusj]

Try these for starters:
http://forum.enjoysudoku.com/viewtopic.php?p=12870#p12870

(Also, I'm not far off uploading a collection of very hard multi-technique puzzles.)

[giant]

thanks. please keep me posted about your collection.
Any other suggestions?

[tso]

http://forum.enjoysudoku.com/viewtopic.php?t=1836
http://forum.enjoysudoku.com/viewtopic.php?t=972

[angusj]

thanks. please keep me posted about your collection.

Here's my latest collection: http://angusj.com/sudoku/ss_undefined_2.zip


And here's the list of all my "advanced puzzles" collections:

Type 1 multicolors:
http://angusj.com/sudoku/ss_multicolor_1.zip

Type 1 and Type 2 multicolors:
http://angusj.com/sudoku/ss_multicolor_2.zip

XY-Wing:
http://angusj.com/sudoku/ss_xywing_1.zip

Puzzles requiring multicolors or xy-wing (getting progressively harder)
http://angusj.com/sudoku/ss_undefined_1.zip

Really hard puzzles requiring many (at least 10) different techniques
http://angusj.com/sudoku/ss_undefined_2.zip

Puzzles requiring forcing chains or other 'exotic' techniques
http://angusj.com/sudoku/ss_unlimited_1.zip

[NorwegianViking]

You want a difficult one?
This one -
"generally regarded to be the toughest known puzzle"
http://www.menneske.no/sudoku/eng/showpuzzle.html?number=4061526

There is a large selection of hard, harder, very hard and super hard puzzles on this site.

[angusj]

You want a difficult one?

You seemed to have overlooked one requirement in the request by of the original poster - "except for guessing"

[DanO]

Unless you are extremely lucky, guessing doesn't help with that puzzle and you are forced to use other techniques such as tables or recursion which the poster hasn't excluded.

[NorwegianViking]

You want a difficult one?

You seemed to have overlooked one requirement in the request by of the original poster - "except for guessing"

Are we SURE that it involves guessing, or is it just that the proper methode hasn't surfaced yet? I mean, just a few days ago Sherlocking brought it a bit further. (Yeah, I know someone regards Sherlocking as guessing.) What if the original poster has developed some revolutionary methode that he wants to test before he publishes it?