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Tough Sudoku for 28/February/2006


Choose a number, and place it in the grid above.

  1 2 3 4 5 6 7 8 9
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Sudoku Solving Techniques

Submitted by: sudoku lover

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Oh well have to be second here.
Good Mean guys. Taking puzzle with me today no time to work on it now.
Can't do the tough's without guessing and always seem to guess wrong.
How do you do it in under 5?
13.11 it's amazing people built that!
Hi all. 8:12 - with 2 guesses. Otherwise it would have taken as long as it took to build the pyramide.
Hugh: Your enjoyment will be greatly enhanced if you learn how to do Sudokus without guessing. You can learn how on Bruno's (GB's) site. You can link to it through 'More' at the top of the page or go directly to http://brunogreco.free.fr/bazar/sudoku/
Please tell me I didn't screw up again, and this one was way too easy....The only thing I did was spot a quad in Be8, and it was all naked pairs and single box fills from there...
Good maen sudoku world
5.26. Would love to be able to go and see them in the 'flesh'.
Say GB?

I have the feeling, that we get the same kind of puzzles lately. Do you still run your equivalence-tests on them? I'm quite curious...

And eh, could we have just 1 (one!!) and only 1 MAEN per day, please?
Thank you!

6:18 - good Maen and hope everyone has a great week.
I guessed as well and one of these days will check out the how-to sites. Meanwhile, off to get something accomplished. Great Maen, all!
Sweetie: I don't see how you did it so easily. Even using all the hints from Simple Sudoku only takes you to 30 filled...
Geez! Two more of them!
Today's is pretty tough (30 after simple eliminations and color fc's, as Andre says, is the best you can do without heavier artillery. aeh1 eliminate a5=3, but to no obvious profit.) Maybe I'll get back to it after work today. Are you there Steve?
okay, I can get to 30 filled and I can find a FC to rid myself of an unimportant 8 in h1, but then.....can someone who actually gets past this point tell me what approach they took to find the next step. Not the step itself, but how they found it. I'm assuming there is some method to this, and not just random divine inspiration.
DJ from AZ: exactly, that's what I need, some heavy artillery.

4:38 best ever
16:12 Unbelievable for me I shall congratulate myself. Hi to all
Christina: I don't have any systematic way of FINDING good ways of elimination, basically am just using trial-and-error. But once an elimination is found, I may have a good way to write it down, so that the others could check it.
14:38 at 2:17am
This was the easiest Tough yet. No fancy logical moves needed (i.e. X & Ys, swordfish etc).
The one is another absolute beast. Sweetie and Freda have made a mistake and got lucky. A quad in block e8 and a hidden pair in row e still don't get you un-stuck. If you feel frustrated by not getting this one, you're in good company. However, trying '8' in cell i9 (which can only be 2 or 8) will lead you quickly to the solution.
good mAen

8:35 start to finish
best for me on tough
mAen to all! Remember when pyramid power was all the rage?
I don't get your elimination of a5=3. Can you help me?
Never mind. I get it now.
12:36 with 2 check moves. I had too many guesses, so couldn't do it right.
OK - this is not an easy puzzle. I have a solution, but it is not pretty. Gonna check it and then write it down ... Hints though... remote weak links.
12:14 with 3 guesses (1 wrong & had to backtrack!) Good mAen all! and a special mAen to Bruck from Snoopnake (where ever that is)!
Good maEn, Bruck, and to all the rest of you, too.
Andre please can you call Kate....
Complete solution - not the best, there are easier and better ways!
1) Start at 22 filled. Easy fillings to 26.
2) Locked 9's forbid 9 at BCI5.
3) EF to 27: Hidden triple 586 at E89, F8.
4) EF to 30: Locked 4's at DF5. Colors on 8's: As Fc: H8==I9--E9==E1 forbids H1=8.
5) Easy Fc: i5=3 == i2=3 -- h1=3 == h1=2 -- h8=2 == i9=2 forbids i5=2.
6) Establish remote weak link f8=6 -- f1=1 per if f8=6 then e9=8, i9=2,c9=1,d9=4
and now new implied pair 19 in column f establishes the weak link.
FC: e1=8 == e9=8 -- e9=6 == f8=6 -- f1=1 == f1=8 forbids a1,f2,f3=8.
7) Establish remote weak link f1=1--d23=4 through implied pair 45 at More...
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