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by:hoke

 
is.gd/hoke545AnnualGoatX

 

by: BP

 
 
Uh, this is tough. With a nice SI we solved hi/lo in A89 and now have 4 solved cells: A4, B45, G1. Anyone any chainfree ideas?

 

by: jgrab

 
 
I didn't get further as well. No idea how to attack the diagonals.

 

by: hoke

 
 
An additional clue at E4 makes it solvable with simple standard tools, which is too easy for a jgrab.
So I am afraid you have to go through all the possible eliminations in the body of the goat, involving some simple and some more elaborated SI/head chains. But of course, you can find the value of E4 in the solution part of the extended URL

 

by: kozibrada

Add to this thread
 
Finally done. Extra hard work with many SI/chains, (skewed) wings (as hoke mentioned) and only 1 Setti I have used to the end; a lot of logic to finding though.
One of the options in H2J1 collapses by using a chain where J3J7 = naked pair which gives H5 little chaining in columns 4, 5 and 6 leads to contradiction. Then the area around C7: there can be eliminated one number that defines hi/lo in row C. |D4 − E5| = 2. Right decision for C7. Position of 4 in row 1. Precise CE in E789. Right decision in F1. Chain on FGHJ6 leads to basic filling in.

Interesting puzzle. Thanks, hoke.

by:morl

 
It's snowing where I live.

is.gd/morl545_1

 

by: AndreasM

 
 
Thanks for this puzzle. It was not that difficult. The final not too serious technical difficulties could be overcome by a combined setti on 1 and 9 which gave it a really nice touch.

 

by: kmr

 
 
Thank you, a very nice one. Not too difficult but not as easy as this week's "regular extreme".

 

by: jgrab

 
 
22 min; very nice! At the end, a little 3-cell interaction replaces the combined Setti mentioned by AndreasM.

 

by: Ollie

 
 
There's always aesthetic quality in your puzzles. I like that very much. Thank you!

 

by: dennis

 
 
really nice, ended it with a y-wing.

 

by: Jens

Add to this thread
 
Qdennis:
y-wing - Congratulation, a new Str8ts-Rule is born.

by:Leren

 

A slightly easier X puzzle. No chains required.


is.gd/Leren_545_X2

 

by: jgrab

Add to this thread
 
Indeed, this one solves directly, not too easy, though. Thanks.

by:jgrab

 
The Annual Goat
As in previous years, I gladly donated a goat for a worldvision project, expressing my thanks to all puzzle creators. Please receive your donation certificate from
is.gd/goat_for_creators
Another goat donation goes, as always, directly to Klaus, our Nestor of puzzle creation. Let's see whether he will again arrange for an Advent calendar ...

 

by: Santa Klaus

 
 
thanks a lot j,

as always, great stuff.

no calendar from myself this year, in times of mass consumption a little piece of chocolate a day seems outdated.

peace and love to all of you.

 

by: Jens

Add to this thread
 
We'll hold your calendar actions in best remind. You're always right - stay healthy and have a good time!

by:Leren

 


is.gd/Leren_545_B2

 

by: witch

 
 
one chain - very nice

 

by: BP

 
 
Again chainless fun with CE and B Setti power. I'd like to point out two B setti moves I really enjoyed:

1. At an early point it's clear that 7 and 8 are missing from col 8. Therefore 7 or 8 must be missing from Box 3, therefore 7 or 8 must be missing from B, therefore 8 not in B34567.

2. After it becomes clear that 8 not in Box 3 it's clear that 7 not in Box 9 and therefore 7 not in H.

 

by: Leren

 
 
Here is another easy B Power move I came up with, which I call Box/Digit conflict.

eg. at 8 solved cells 9 in A1 would cause both A2 and B1 to be 2. Since this can't be True, A1 <> 9.

A 3 cell SI or maybe just call it a standard B Power move.

 

by: Leren

 
 
@ BP

wrt your 1. Early on you also know 7 is in B => - 8 in B and Box 3

 

by: Berny

 
 
@BP and Leren:
As I mentioned two weeks ago I'm new in this B-stuff. I can see that 7 and 8 are missing in col 8. So the "usual" rules say they must be missing in row B or H. It's easy to find 7 is missing in H (and must be in B).

But: How do I know that 7 or 8 must be missing in box 3??? (I assume 3 is ABC789, correct?)

 

by: BP

 
 
@Berny: For B str8ts the following rules hold:
1. If a digit is missing from a box it must be missing from at least one of the rows and at least one of the cols intersecting with that box.
2. If a digit is missing from a row/col it mus be missing from at least one of the boxes intersecting with that row/col.

(The proof by contradiction is not difficult.)

In this case that means: Only 7 and 8 are missing from cols 7,8,9. Thus one of both digits is missing from box 3 the other is missing from box 9.

The above observation is really powerful in dealing with B str8ts. I use it all the time in different situations.

 

by: Berny

Add to this thread
 
@BP:
Thank you, got it now! Indeed powerful...

by:Leren

 


is.gd/Leren_545_B1

 

by: witch

 
 
is there a unique solution? I don't have one (F56=H56=56). Maybe I missed something!?

 

by: Leren

 
 
@ witch

In my solution there are no 5's in FH56.

 

by: witch

 
 
thnx - now it's unique

 

by: BP

Add to this thread
 
Chainless fun, many thanks.

by:Leren

 


is.gd/Leren_545_X

 

by: jgrab

 
 
Very, very hard. Took me 32 hours. All kind of tools, but mainly HCs.

 

by: pets

 
 
Phew - took me longer than jgrab - really tough!
Loaded with dependencies, but couldn't find a chainless way, either. Thank you, Leren!

 

by: jgrab

 
 
Sorry for the typo: should read "2 hours"

 

by: AndreasM

 
 
Seemingly easier than last week's X-puzzle as the high-low decisions are not that difficult to make. But solving it took me nevertheless quite some time. Thanks for the puzzle.

 

by: BP

 
 
@Leren: Is there really no chainfree way forward? So far I got all hi/lo decisions and A79, D1, E3, F456.

 

by: Leren

 
 
@ BP

Look for a 3 cell SI in G3 & H23.

 

by: BP

 
 
@Leren: Many thanks for the hint! Actually I didn't see an SI in G3H23, but staring at that area I noticed an x-power step I had previously overlooked. With that and two more short SIs the puzzle actually solved chainfree. A really great challenge, thank you for that!

 

by: Leren

Add to this thread
 
@ BP

The SI was 5 r8c3 => 4 r8c2 => 3 r7c3 => - 5 r8c3.

Then 5's in H28 removes 5 from B28 etc

by:Leren

 


is.gd/Leren_545

 

by: AndreasM

 
 
After an uncharacteristically slow start it went rather smoothly. Thanks for this really fine puzzle.

 

by: Jens

Add to this thread
 
BCA2 needed long chains, but solved.

by:Leren

 


Reserved for discussion of Andrew's puzzle.

 

by: Jens

 
 
Solvers job

 

by: Jan

 
 
Well, almost. You do one x-wing and one setti.

 

by: hoke

 
 
Like Jan, for me 1 hour of fun wc.

 

by: Andrejs

Add to this thread
 
First I solved the puzzle without using a solver. It wasn't hard. I use two URs, one XW and two settis (on 1 and 8). Now I see that it could have been simpler to deal with. Thanks!



Article created on 27-June-2010.
This page was last modified on 16-March-2020.
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  • 14' setti
       - Arjan - 1 day ago
  • 36 min
       - relijo - 1 day ago
  • 13' easy going nice for a lazy afternoon, thx.
       - yaya - 2 days ago
  • 19min
       - GML - 3 days ago
  • 23` easy one
       - Chris - 3 days ago
  • 22 min - 1 setti. Nice
       - Drefplin - 3 days ago
  • 👍
       - Kmk - 3 days ago
  • 33min. no setti needed
       - dersoloist - 3 days ago
  • 17' pure logic. too easy for 2 star.
       - Gottfried - 4 days ago
  • Logic, but just challenging enough
       - cee - 4 days ago
  • nice
       - essie - 4 days ago
  • 12:50 I did it again!-)
       - Latimer - 4 days ago
  • 15', takes attention and 2 settis, very nice one
       - Klaus - 4 days ago
  • 15' - 3rd approach. 1 Setti required for me. Very nice, thanks!
       - carpat66 - 4 days ago
  • 20 min 1 setti
       - MoHo - 4 days ago
  • 11 minutes. One or two x-wings and the rest was simple elimination.
       - puzxzled - 4 days ago
  • 2h02min. - left without stopping time ... one guess
       - joeB - 4 days ago
  • 21 min. very nice. Definitely needed more than one setti
       - juehe - 4 days ago
  • 60 - 1 setti and logic. Thanks to Andrew
       - Hubert - 4 days ago
  • done without candidates, two settis and one mental x-wing
       - Jan - 4 days ago
  • 20' - easy with a setti or two
       - selecti - 5 days ago
  • fun; my 5th of these solved (but none of the 2 day ones yet)
       - optimator - 5 days ago
  • 23' 1 Setti needed.
       - Aubinger - 5 days ago
  • 11 min - one setti did it
       - Antonio - 5 days ago
  • 19 min. much fun. Thank You, Andrew.
       - Axel - 5 days ago
  • pure logic - at the third attempt :-( but it is really a nice one
       - j0ppy - 5 days ago
  • 10 min
       - Cminor - 5 days ago
  • 12 min - pure logic
       - BriGs - 5 days ago
  • nice & doable
       - jgrab - 5 days ago
  • 15 min - one setti and one wing
       - Michael - 5 days ago