Sudoku Puzzles

Good morning everybody! I just want to thank Gath for an improvement to the site I noticed recently. Somewhere along the line, the program changed so that the original picture still stays linked with its puzzle - so now if you do the puzzle from May 12, you get the picture from May 12, instead of More...

Thanks for pointing that out Jill. And thanks Gath!

Good Maen to all! Great picture Keyan!

I don't hit the archives too much, because I come here daily. Good to know though, thanks Jill.

I hate doing these puzzles without a mouse though, makes it tougher and longer than it should be!

Solution to tough sudoku of 08 27 06:

1) Start at 23 filled - the given puzzle. Unique Possibilities to 25 filled. (UP 25).
2) Hidden pair 28 at i26 forbids i2=16, i6=13 UP 26
3) Locked 9's at h23 forbids h45=9 UP 31
4a) Hidden pair 68 at ef3 forbids e12,f1=8, e3=37, f3=23
4b) More...

Anyway - regarding the Sue ... technique. The way I see it, it is nothing more than an ALS with the two sets non-discreet. It really is not a special case at all, unless I am missing something. This is one of the reasons I do not memorize technique names, as they often are just a lack of generalization of another technique. For example, xw wings are also a subset of ALS.

Hurried through publishing today's proof, as I had to take son to footgall game. I believe that a depth 3 solution maybe possible. For the record, my solution uses:
sets: 2+1+2+1+4+1+1+3+2+2+3+4= 26
Max depth 4 at steps 4c,6.
Rating: .6

Another great picture from Keyan.

5:08

Thanks for pointing that out, Jill, I had also noted it and appreciate it immensely. I don't always get here daily, so it's nice to see the pictures that the comments relate to. Thanks to Gath for another great job. maEn

6.09
was that in the wrong section, way too easy for a tough one
have a great day/night one and all

Thanks Jill! I'll go and do the Hard from yesterday with my daughter! I was locked out of the site all day yesterday and this morning yet it doesn't seem that others had trouble? Very strange.

5.07

Maen all! Thanks for the comments about the picture. It was the same night as the fireworks...right after the fireworks, a full moon rose above the Bay.

I was locked out yesterday, too.

to Steve:
basically I found the same as you (although I needed
a little more clean up in hidden pairs, locked sets etc. - couldn't reproduce your locked 9 h23 though)
UPs a little different (UP 48 after the xy wing)

tried hard to find depth 3 but failed.

Hi Pat after the hidden pair elimination, up 26 (g2=6), yielding the locked 9's h23.
Up 48 is what you should have if you use a few more pairs, locked sets before applying the fc's. Up 44 is the result of paring down solution.

My apologies!
6) a3=2 == a3=7 -- d3=7 == d2=7 -- d2=4 == d9=4 -- b9=4 == b9=2 forbids a8,b3=2
Up 81 is faulty due to d3=7 == d2=7 not true. e2=7 still exists as a possibility

Replacement step:
{Pair 27 at a23} == a2=4 -- d2=4 == d9=4 -- b9=4 == b9=2 forbids a8,b3=2 UP 81

Sorry. Depth os step is still 4.

Over an hour to solve.....

cockpit

SE=7.2