Get the Str8ts App
Welcome to the home of Str8ts

#666, March 26 - April 1:
The Weekly Extreme Str8ts Puzzle

by Andrew Stuart

WARNING: This is the Weekly 'Extreme' Str8ts.
Only attempt this puzzle if you have time and patience.
Using the solver will not help you. (much).

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.
Share and Enjoy
Puzzles 1 to 250 are available as Puzzle Packs, just $5.49. Pack 3, 4 and 5 just released!

Posts you have NOT read are in normal colors, older ones are in grey.
Please email me if you experience problems or bugs. Cheers, Andrew Stuart

Your Name or Handle

Your comment or question

Enter these letters arrow

Please keep your comments relevant to this article.
To state your solve time use the smaller form at the top right of this page.
Line breaks and paragraphs are automatically converted. No need to use <p> or <br> tags.
No full solutions please!

by: Klaus


after basic and careful elimination the situation seems a bit desperate.

but some assumptions in row C give rather short contraditions to Setti on 8.

and thats enough, beautiful puzzle.


by: Cosmanita

Nice one, and as Klaus said, a close look on C and setti 8 is a good start, I also needed to include column B and a X-Wing on 6.


by: ralph maier

After basics etc mysolution was based on high low in column2 w3as my way tothe solution . Low inthee lcolumn ghj column2 leads to a contradiction after it it was carefull eliminations


by: pax

Used a HC to decide hi/low in D.


by: ralph maier

Add to this thread
sorry i meant column5 not2

by: kst


by: Martinus

Very nice excercise, needed settis and b settis. Thanks a lot!


by: pax

Since the B-explanations last week I know, what b setties are... helps a lot :) . Thanks, kst!


by: AR

Could you please share the information? Thank you!


by: Mikele

please anybody explain b-setti again


by: Aubinger

In the archive box above select the puzzle from last week and press 'show puzzle'. Then you will get discussion from last week.


by: AR

Thank you so much, Aubinger.


by: Mikele

Thank You, Aubinger


by: Aubinger

@AR, @Mikele: You're welcome.


by: kmr

Very difficult for me. Key was that there are only two numbers possible for J2, one leads to a missing number in column 7 or 8. Then very CE and still not easy to spot all the x-wings.


by: BP

Another fine example for the power of B settis, which for example helps clear J2 immediately.

B setti on 8:
After initial CE (NQ12345 in Box9, NQ5789 in Box1) it's clear that 8 is not in col 1 and not in A. Since 8 in Box1 this means that 8 must be missing from Box 2 or 3 AND from Box 4 or 7. Therefore 8 is missing from another row and another col, which can only be col 9 and J.

setti 2: J2=2

B setti on 8,9:
8 and 9 are the only digits missing from rows A,B,C. Since 8 is missing from Box3, 9 must be missing from Box2, which implies BC5=68.
By the same argument 9 is missing from Box6, which implies 9 not in E.

Thank you, kst, for this enjoyable exercise.


by: ralph maier

Add to this thread
quite a hard1 one after many years of absence from my side/ looking at the posts idid BPs reasoning not being aware of it . Iussed 1 guess in A23 about the ositions of the 5and7 THE REST WAS SEELIMINATIONS AND LOGIC.

by: kst


by: Martinus

Also a nice difficulty level, b settis and settis. Thanks!


by: BP

Add to this thread
What a beauty, tough but chainfree. VCE (especially in J and boxes 1 and 9) and B settis did it. Many thanks, kst!

BTW: This puzzle contains another nice example how to use B settis. After initial CE it's clear that 2 in cols 1,2,3,4,5,6 and therefore in boxes 4,5. Since 2 is in box 6 from the beginning this implies that 2 must be in D,E,F, which is very helpful.

by: kst


by: proteus

thanks kst for this tricky puzzle. needed all the x-tools and some careful considerations in A123 in the end.


by: BP

Very nice. Standard tools plus one almost fish to solve A1.


by: MavenKC

Add to this thread
Took me exactly 1hr. Great challenge!

by: kst


by: Martinus

Add to this thread
One very interesting UR/wing-combination, plus normal UR and settis. Very enjoyable. Thanks!

by: Fred

Heftig. Falls nicht noch irgendein Hint daherkommt, für mich völlig uninteressant.


by: Rübennase

Add to this thread
Tricky! I started over twice, having jumped conclusions.
CE on F1 and rows CD. Two Setti-assisted HCs to trim compartment ranges in col 1. Enter an Xwing (that I wish I had seen much earlier!) and the puzzle collapses.

Page created on 27-June-2010.
This page was last modified on 08-Jan-2023.
All puzzles on this site are trademarked and cannot be reproduced without permission.
Copyright Syndicated Puzzles Inc, 2010-2023
Boast or Rant!
Tell everyone if you solved this puzzle, how long it took or if you gave up.
Name or handle:

including time to solve (or not :)

For questions or discussion, please use the main comment form.
  • 29' - Only with the hint on D8
    - LK
  • 42 min im 4. Versuch
    - Rot
  • 36min easy with hints Thanks!
    - CC
  • took me quite a long time on several attempts
    - Ske
  • Mit D6 zuerst 1 geraten, das war falsch. Damit ist klar, wo high und low in Zeile D ist. Dann viele Settis. Schön anspruchsvoll. Danke
    - S. Walt
  • ~60' great one! careful logic, finally found Xwing, then settis
    - optimator
  • 1h, with the hint of Klaus, no guessing or spoiler needed, only short interactions with setties.
    - Cosmanita
  • took me 49 min, but in the end it was just logic...
    - EC
  • about 30 min
    - Loser
  • 11' hi-lo-decision in column 2 and row G
    - Arjan
  • Nice with Korbinians hint (thanks a lot), no chance without
    - Fred
  • 25 min with some chains
    - Setti
  • about 1hr (with breaks). Thanks to Korbinian and Andrew!
    - barbara
  • 47' one high low deision
    - Manfred
  • 13 min with all hints - to Torsten&Irina: not D8 =2, but C8=2, because you have to think small in D234 as Korbinian correctly said.
    - Susi
  • 20 min, just filling in, no guesses, no hints, no settis, a few singles and pure logic
    - Nina
  • Easily two hours (but then, I'm down with a cold). No guessing needed. Very nice challenge!
    - Rübennase
  • 27 min - with lucky decision in A2, no hints. A beautiful puzzle, loved it. Thanks!
    - Beate
  • 15 min, straight forward
    - Cminor
  • Needed the hint.
    - mparmen
  • 44 min - thank you, Andrew, for this real challenge
    - Nessi
  • 19 min with Korbinians hint
    - juehe
  • Using Korbinian's hint about 20min
    - Richard
  • >2h. Took me some chains in order to exclude some possibilities, which seemed to me not probable.
    - MartinL
    - effchen
  • 35:21 - tough one. Thinking small in D234, C678 and EF1 and thinking big in G89 may help a little bit.
    - Korbinian Bär
  • 45 min, wings, settis, D8!=2
    - Torsten&Irina
  • 33min; solvable only with a guess in row g
    - Martin
  • 30' settis and a hi/lo guess in row c
    - Bassam
  • 35” but difficult - finding 9 in column 3 helps to make progress quickly, still all tools needed
    - OneGuess
  • 35” but difficult - finding 9 in column 3 helps to make progress quickly, still all tools needed
    - OneGuess