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1 to 25 - on the iPhone
Since there has been interesting strategy discussion on these puzzles and by popular request, I have opened an archive on the last thirty weeks. The discussion section is open for continued posting.
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Puzzles 1 to 250 are available as Puzzle Packs, just $5.49. Pack 3, 4 and 5 just released!

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by: bansalsaab

Thanks Stefan for this puzzle. mostly CE and one SI in the end.


by: pax

Thanks, Stefan, I used an UR in the end instead of the SI.


by: Andy B.

Thanks a lot Stefan - great puzzle - I went for the UR.


by: jgrab

Thanks, Stefan. Rather complicated; after CE, needed a 4-fish a little heead chain towards the end.


by: hp

like jgrab, thank you Stefan
see no way to avoid one chain (no 5 possible in D4)


by: Berny

@hp: I think for D4 you don't need a chain but the UR - if D4 would be 5 there is no way left to decide in D7 between 1 and 7.


by: hp

@ Berny:
clever, you are right and i made not all implications of the Island UR
so another chainless masterpiece from Stefan


by: Leren

There is a second UR DJ12 => DJ1 <> 5, which solves without a chain.


by: Jan

After eliminations and two singles, there are two 4-wings and two x-wings that solve many cells. At that point, I used the one half of the UR which solves J7. Even if you use the second half solving D4, you remain with the reactangle D-J1-4 unsolved and need a head chain. You might as well use it after the first part: One choice for H4 immediately leads to a contradiction, the other quickly solves.


by: Christoph

Add to this thread
Excellent challenge, Stefan.
It took me a while to see the consequences of candidate 5 in D4!
Solves with CE, two fishes and a couple of URs. Thanks a lot.



by: pax

Nice one, mainly setties. Thank you, Hone


by: hp

Thank you hone i Like this level of difficulty
BCA in every conseivable variants
Island is maybe Sylt?


by: kmr

Nice one, numerous settis but not at all easy.


by: hone

@hp: it is


by: jgrab

Thanks; besides many Settis, used a triple UR, doubles and triples.


by: Jan

Add to this thread
A setti solves a cell, an x-wing determines the contents in row E and generates a single, a 3-wing solves several cells with the digit concerned; this gets you to nine solved cells. At this point, all rows and columns but one contain a certain digit, but in the column concerned, it has only one candidate cell; thus you can remove it from the other cells in that row. This enables an x-wing on a rare digit which solves. Oh, and you have to do your eliminations properly in between!



by: jgrab

Quite challenging! Settis, wings, CE, and two head chains towards the end.


by: Maven

Add to this thread
Same here. Thanks


@ Andreas
Eine grundlegende (=logische) Regel besagt, dass die Anzahl jeder Zahl in den Zeilen und Spalten gleich sein muss. Der erste, der dies beschrieben hat, war der Spielter "Setti". Daher stammt der Name: "Setti-rule".


by: joeB

Add to this thread
but wait, there's more:
settis rule is powerful, if only "must have" candidates remain in rows or columns - then the opposite (column/row) contains "must have" candidates as well



by: ThomasF

thanks Leren, this one was nice. Some Setti, wings, gaps and an UR followed by a small fish


by: jgrab

Very nice, thanks. Needs full set of standard tools.


by: kmr

Very nice. Yes, standard tools, however, nearly all and in a challenging way.


by: hp

Tough for me, ty Leren
See no way without a chain after 27 solved cells.
Made application of bca3; xwing6; UR left bottom and swordfish2.


by: Ben

Like hp, I needed a couple of SI's after 27 solved cells.


by: Jan

Add to this thread
Agreed, you need a chain, although the right one is doable in your mind: If you assume D6=3, one obvious path leads to H4=3, while another obvious path leads to C4=3. The alternative solves easily.

I find particularly interesting that row F, even before you fill in anything, already defines two settis that, in consequence, define the contents of column 5.

Article created on 27-June-2010.
This page was last modified on 17-April-2011.
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  • Very nice one :-)
       - hiitsme - 16 hours ago
  • 39 min, a lot of settis
       - hopplahierkommich - 18 hours ago
  • 18:50 lots of naked pairs, no settis used
       - hildi - 1 day ago
  • 26
       - Jochen - 2 days ago
  • 11', Quite straightforward. Maybe I made an incorrect logical deduction that just happened to give the right solution!
       - Amazed - 3 days ago
  • 24' second attempt - nice
       - relijo - 3 days ago
  • 46' - standard tools
       - selecti - 3 days ago
  • solves with C3 = 1 in few minutes
       - flowermount - 3 days ago
  • nice one to chillax :)
       - silke - 4 days ago
  • 18 min - but I don't know whether it is correct or not - missing message at the end
       - Elfriede - 4 days ago
  • 20min, thanks for that and no (wrong) error message
       - fred - 4 days ago
  • 35 min. without chains
       - joeB - 4 days ago
  • 35:00 x-wings and settis and naked pairs
       - joe reitzl - 4 days ago
  • 25' - nice one
       - Coco - 4 days ago
  • Relatively easy. x-wings and Setti on 2 did it.
       - Toni - 4 days ago
  • 15' this time using several setties (thanks to Jim Knopf I finally knows what it is!
       - Arjan - 4 days ago
  • 24' with 3 tries on E6 (the last one worked)
       - Arjan - 5 days ago
  • 32 min with lots of setties, naked pairs and even simple logic - nice to solve
       - Reus - 5 days ago
  • done with no Settis at all, only xwings
       - ataraxia - 5 days ago
  • ca. 2 stunden(Danke jimknopf für die erklärung der settis)
       - wjanet - 5 days ago
  • 40'
       - quantango - 5 days ago
  • Lots of Setti, x-wings, very nice!
       - Alan Bourdillon Traherne - 5 days ago
  • 29 min. nice and not too difficult.
       - Boerny - 5 days ago
  • '34, easy this week
       - Sabine - 5 days ago
  • 32' settis and logic
       - Lilli - 5 days ago
  • 29 min nice one settis
       - schaaf - 5 days ago
  • 20 min ... nice!
       - Stef - 5 days ago
  • 33 min lots of x-wings and settis
       - juehe - 5 days ago
  • 15' all in all. At some point a deadly pattern over 3x3 cells in the bottom right hand quarter, then a final setti on 4
       - Marc - 5 days ago
  • 23 min - very nice, settis and logic
       - Susan - 5 days ago