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Andrew

Post subject: Archive Part H. Assassins 201-225, variants, other puzzles

Posted: Thu Dec 01, 2011 11:40 pm

Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1895
Location: Lethbridge, Alberta, Canada

This is Part H of the Assassin Forum Archive, continuing to include puzzles posted on this site and provide easy links to the puzzles and threads. Please read the first part of the Archive Index to get the background to this archive including Mike (mhparker)'s original post about ratings.

Puzzle rating table, with links to archive entries; each of these has a link to the puzzle thread.

Abbreviations used in Rating Table:

+-------------------------------+-----------+---------+----------+----------+
| Puzzle                   Est  |  Made By  |  Rating | SS Score | SS Score |
|                               |           |  Andrew |  v3.3.1  |  v3.5.7  |
+-------------------------------+-----------+---------+----------+----------+
| Human Solvable 8 Boxes        |  HATMAN   |         |          |          |
| Human Solvable 8 Boxes V2     |  HATMAN   |         |          |          |
| Assassin 201 V0.8             |   Børge   |  E1.00  |   0.80   |   0.90   |
| Assassin 201 V0.9             |   Børge   |   1.00  |   0.85   |   1.00   |
| Assassin 201 V1               |   Børge   |  H1.25  |   1.15   |   1.05   |
| Assassin 201 V2               |   Børge   |  H1.50  |   2.50   |   2.15   |
| goooders' Special 1     H1.75 |   Børge   |   1.50  |   7.00   |   3.95   |
| Assassin 202 V0.85            |   Børge   |  E1.50  |   0.85   |   1.00   |
| Assassin 202 V1               |   Børge   |  E1.25  |   1.20   |   1.10   |
| Assassin 202 V2               |   Børge   |   1.75  |   1.20   |   1.55   |
+-------------------------------+-----------+---------+----------+----------+
                                   Page #1

+-------------------------------+-----------+---------+----------+----------+
| Puzzle                        |  Made By  |  Rating | SS Score | SS Score |
|                               |           |  Andrew |  v3.3.1  |  v3.5.7  |
+-------------------------------+-----------+---------+----------+----------+
| Assassin 203                  |    Ed     |   1.50  |  *1.60   |   1.45   |
| Paper Solvable 5              |  HATMAN   |   1.25  |          |          |
| Weekly No.256 @ KSO           |   Other   |  H1.25  |  *1.45   |   1.30   |
| Assassin 204                  |    Ed     |   1.50  |  *2.00   |   1.70   |
| Assassin 205                  |    Ed     |   1.50  |  *1.55   |   1.40   |  
| Assassin 206                  |    Ed     |  E1.50  |  *1.60   |   1.55   |
| Assassin 207                  |    Ed     |  H1.50  |  *1.70   |   1.55   |
| Assassin 208                  |    Ed     |  E1.50  |  *1.85   |   1.65   |
| Assassin 209                  |    Ed     |  E1.25  |  *1.30   |   1.25   |
+-------------------------------+-----------+---------+----------+----------+
                                   Page #2

+-------------------------------+-----------+---------+----------+----------+
| Puzzle                        |  Made By  |  Rating | SS Score | SS Score |
|                               |           |  Andrew |  v3.3.1  |  v3.5.7  |
+-------------------------------+-----------+---------+----------+----------+
| Paper Solvable 6 Decidoku     |  HATMAN   |         |          |          |
| Assassin 210                  |    Ed     |  H1.50  |  *2.15   |   1.95   |
| Assassin 211                  |    Ed     |  E1.50  |  *1.25   |   1.45   |
| Assassin 212                  |    Ed     |   1.50  |  *1.20   |   1.15   |
| Assassin 213                  |    Ed     |  H1.50  |  *1.65   |   1.55   |
| Assassin 213 V1.5             |    Ed     |   1.75  |  *2.05   |   1.70   |
| Paper Solvable X W 7          |  HATMAN   |         |          |          |
| Assassin 214                  |    Ed     |  H1.25  |  *1.35   |   1.25   |
| Assassin 215                  |    Ed     |  E1.50  |  *1.65   |   1.40   |
+-------------------------------+-----------+---------+----------+----------+
                                   Page #3

+-------------------------------+-----------+---------+----------+----------+
| Puzzle                        |  Made By  |  Rating | SS Score | SS Score |
|                               |           |  Andrew |  v3.3.1  |  v3.5.7  |
+-------------------------------+-----------+---------+----------+----------+
| Discussion of Perfect Killer  |   Other   |   1.25  |  *1.50   |   1.40   |
| Assassin 216                  |   Børge   |   1.50  |   1.40   |   1.30   |
| Assassin 216 V0.5             |   Børge   |   1.25  |   0.95   |   0.95   |
| Assassin 216 V2               |   Børge   |  H1.50  |   2.50   |   2.05   |
| Assassin 216 V7               |   Børge   |   2.50  |   7.00   |   5.00   |
| Assassin 217                  |   Børge   |   1.50  |  *1.70   |   1.40   |
| Assassin 218                  |    Ed     |   1.50  |  *1.40   |   1.30   |
| Assassin 219                  |    Ed     |   1.50  |  *1.50   |   1.45   |
| Assassin 220                  |   manu    |   1.25  |  *1.25   |   1.15   |
+-------------------------------+-----------+---------+----------+----------+
                                   Page #4

+-------------------------------+-----------+---------+----------+----------+
| Puzzle                        |  Made By  |  Rating | SS Score | SS Score |
|                               |           |  Andrew |  v3.3.1  |  v3.5.7  |
+-------------------------------+-----------+---------+----------+----------+
| Assassin 221                  |   manu    |  H1.50  |  *1.85   |   1.55   |
| Paper Solvable 8              |  HATMAN   |   0.50  |   0.75   |   0.85   |
| Human Solvable 9              |  HATMAN   |   1.50  |   3.55   |   2.60   |
| Assassin 222                  |    Ed     |  H1.50  |  *1.65   |   1.55   |
| Assassin 223                  |   manu    |  E1.50  |  *1.35   |   1.25   |
| Assassin 223 V2               |   manu    |  H1.25  |  *1.25   |   1.35   |
| Assassin 224                  |    Ed     |  H1.50  |  *1.75   |   1.55   |
| Double Diagonal 1             |  HATMAN   |   1.50  |          |          |
| Paper Solvable 9 Elevenses    |  HATMAN   |   0.50  |          |          |
+-------------------------------+-----------+---------+----------+----------+
                                   Page #5

+-------------------------------+-----------+---------+----------+----------+
| Puzzle                        |  Made By  |  Rating | SS Score | SS Score |
|                               |           |  Andrew |  v3.3.1  |  v3.5.7  |
+-------------------------------+-----------+---------+----------+----------+
| Assassin 225                  |  HATMAN   |  E1.50  |   1.60   |   1.60   |
| Double Diagonal 2             |  HATMAN   |         |          |          |
+-------------------------------+-----------+---------+----------+----------+
                                   Page #6

Some of the selected quotes in the puzzle entries have been edited to remove "spoilers"; the full rating comments are included with the walkthroughs. In some cases the puzzle makers gave hints; these are included in tiny text in the selected quotes.

Many thanks to Ed for providing the format for the rating tables, including links to the puzzle threads; I think it was a great idea that in the rating tables he provided separate columns for the most regular posters of ratings. Thanks also to Børge for generating so many diagrams, which are also in the Images with "udosuk Style Killer Cages" thread, and for providing links from diagrams in that thread to the archive entries.

If you solve any of these puzzles and decide that there aren't enough walkthroughs for that puzzle or, better still, that you've found an interesting way to solve it which hasn't been posted, please feel free to post your walkthrough in the puzzle thread. Your comments and walkthrough will then be added to this archive.

Last edited by Andrew on Wed Feb 27, 2013 11:04 pm, edited 2 times in total.

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Andrew

Post subject: Archive Part H. Assassins 201-225, variants, other puzzles

Posted: Sat Feb 23, 2013 11:35 pm

Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1895
Location: Lethbridge, Alberta, Canada

Human Solvable 8X Boxes by HATMAN (October 2010) here

Puzzle Diagram:

Image with "udosuk style Killer Cages" by Børge:

Code: Select, Copy & Paste into solver:

Solution:

+-------+-------+-------+
| 8 5 6 | 1 7 3 | 2 4 9 |
| 4 3 2 | 5 6 9 | 1 7 8 |
| 7 9 1 | 4 8 2 | 3 5 6 |
+-------+-------+-------+
| 2 8 7 | 6 3 1 | 4 9 5 |
| 3 6 4 | 7 9 5 | 8 2 1 |
| 5 1 9 | 2 4 8 | 7 6 3 |
+-------+-------+-------+
| 9 7 8 | 3 2 6 | 5 1 4 |
| 6 4 5 | 8 1 7 | 9 3 2 |
| 1 2 3 | 9 5 4 | 6 8 7 |
+-------+-------+-------+

Quote:

HATMAN: I've had this human solvable for a while - however I have versions with different levels of difficulty and could not decide which to publish. This is the second hardest.
JSudoku solves it with trouble and fishes.
Interesting box interactions - as they say enjoy.

Ed: This is still a HUS puzzle for me. Here are examples of the interesting interactions I found of which there are other eliminations but nothing to crack the puzzle. Hope someone else can see something. If we can't crack it, perhaps HATMAN can give us a hint after the weekend.

HATMAN: I'll try and think of a cryptic clue description over the weekend and post on Monday/Tuesday.
I'm happy that the HS part was not seen immediately.

simon_blow_snow: Thanks for the nice puzzle. Not too easy, not too hard!

Hopefully the "hardest version" is also human easily solvable like this one. 8-)

Ed:

HATMAN wrote:

I'm happy that the HS part was not seen immediately.

You're welcome! You'll be even happier that I gave up! I would have given up way earlier if that easy placement wasn't available.
Welcome simon_blow_snow! I didn't really understand how you did step 2 but think it must work like this. It's only just clicked now doing this post!!

HATMAN: Glad you enjoyed it Ed
Note Simon has been doing my puzzles for a while on DJApe's (defunct) site.

Andrew: Thanks HATMAN for another challenging Human Solvable puzzle.

I got the first Human Solvable step, the one in N5, quickly enough but soon got stuck because I wasn't able to find the second Human Solvable step. I won't post a walkthrough; some of my steps were very messy.

(Archive Note) The thread also contained discussion regretting the loss of DJape's and Ruud's sites. To access this, click on the link at the top of this entry and then scroll down the Human Solvable 8 Boxes thread.

Ed’s start:

Walkthrough by simon_blow_snow:

Ed's discussion of Simon's step 2:

Andrew's comments about Simon's key steps:

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Andrew

Post subject: Archive Part H. Assassins 201-225, variants, other puzzles

Posted: Sat Feb 23, 2013 11:48 pm

Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1895
Location: Lethbridge, Alberta, Canada

Human Solvable 8X Boxes V2 by HATMAN (October 2010) here

Puzzle Diagram:

Image with "udosuk style Killer Cages" by Børge:

Code: Select, Copy & Paste into solver:

Solution:

+-------+-------+-------+
| 8 5 6 | 1 7 3 | 2 4 9 |
| 4 3 2 | 5 6 9 | 1 7 8 |
| 7 9 1 | 4 8 2 | 3 5 6 |
+-------+-------+-------+
| 2 8 7 | 6 3 1 | 4 9 5 |
| 3 6 4 | 7 9 5 | 8 2 1 |
| 5 1 9 | 2 4 8 | 7 6 3 |
+-------+-------+-------+
| 9 7 8 | 3 2 6 | 5 1 4 |
| 6 4 5 | 8 1 7 | 9 3 2 |
| 1 2 3 | 9 5 4 | 6 8 7 |
+-------+-------+-------+

Quote:

HATMAN: For the harder version leave out the twin cage 26(4) at r6c6. Overlap innies seems a resonable description of the technique.

simon_blow_snow: Turns out the harder version is just a little bit harder:

Andrew: Thanks Simon for great walkthroughs for the original puzzle and for the harder version :applause:

.
Andrew's comments are included in the previous archive entry.

Walkthrough by simon_blow_snow:

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Andrew

Post subject: Archive Part H. Assassins 201-225, variants, other puzzles

Posted: Sun Feb 24, 2013 2:53 am

Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1895
Location: Lethbridge, Alberta, Canada

Assassin 201 V0.8 by Børge (October 2010) here

Puzzle Diagrams with "udosuk style Killer Cages":

Code: Select, Copy & Paste into solver:

Solution:

+-------+-------+-------+
| 7 1 5 | 3 8 6 | 9 4 2 |
| 3 4 6 | 2 5 9 | 8 7 1 |
| 2 9 8 | 7 4 1 | 6 3 5 |
+-------+-------+-------+
| 4 3 9 | 6 1 2 | 5 8 7 |
| 5 8 1 | 4 9 7 | 3 2 6 |
| 6 7 2 | 5 3 8 | 4 1 9 |
+-------+-------+-------+
| 1 5 4 | 9 7 3 | 2 6 8 |
| 9 2 7 | 8 6 4 | 1 5 3 |
| 8 6 3 | 1 2 5 | 7 9 4 |
+-------+-------+-------+

Quote:

Børge: SS score 0.81

Andrew: After V1 and V0.9, I moved on to the other cage pattern with V0.8. I hope Børge won't mind me saying that patterns with lots of diagonally connected cages aren't my favourites, because it's harder to keep track of the cages on my worksheet and because they provide fewer 45s; in this case the only useful 45s that I found were for corner nonets. I'm not saying that people shouldn't post such puzzles, just not too often. When I first looked at the cage pattern I was initially concerned that I would find it difficult to keep track of the diagonally parallel 19(3), 19(3) and 19(4) cages although they proved not to be a problem.

As you will see from my walkthrough, after having missed a simple step for V0.9, I did the same for V0.8. It must be the effect of my age!

In this case the simple step made such a difference to the solving path that I re-worked my walkthrough from that stage, as I've commented below after step 5.
Rating Comment. I wasn't really sure how to rate A201 V0.8 because the critical steps were both CPEs, in steps 1d and 5, with the one in step 1d being the harder of those two CPEs. I'll rate my walkthrough for A201 V0.8 at Easy 1.0 although it's arguable that's a bit low.

goooders: I absolutely agree with Andrew that puzzles with diagonally connected cages are essentially tedious.

Børge: I do not mind at all.
I am in fact very grateful that people speak up and say what they prefer end not prefer.
As I have said before, my knowledge of Killer Sudokus is limited, but I like doodling cage patterns.
Here six cage patterns I have doodled.
If you would like to see an Assassin having one ore more puzzles with one or more of these cage patterns, please speak up.

(Archive Note) These patterns are posted here. Please see the thread, starting from this point, for discussion between Børge, Andrew and goooders, with further patterns posted and discussed.

I can't resist including a bit from the end of the discussion here
Børge: You don't know all the fun you miss out on:

Andrew: Nice Smiley, Børge!

Walkthrough by Andrew:

Assassin 201 V0.9 by Børge (October 2010) here

Puzzle Diagrams with "udosuk style Killer Cages":

Code: Select, Copy & Paste into solver:

Solution:

+-------+-------+-------+
| 8 6 4 | 3 7 2 | 1 9 5 |
| 1 7 2 | 8 5 9 | 4 3 6 |
| 9 3 5 | 4 6 1 | 8 7 2 |
+-------+-------+-------+
| 2 4 8 | 1 3 7 | 5 6 9 |
| 5 1 3 | 9 4 6 | 2 8 7 |
| 6 9 7 | 5 2 8 | 3 1 4 |
+-------+-------+-------+
| 4 8 1 | 6 9 5 | 7 2 3 |
| 3 2 9 | 7 8 4 | 6 5 1 |
| 7 5 6 | 2 1 3 | 9 4 8 |
+-------+-------+-------+

Quote:

Børge: SS score 0.83

Andrew: After doing the V1, I decided to try the V0.9 next because it has he same cage pattern. Unlike the V1, which I found flowed nicely, I struggled with V0.9 but that was because I'd missed a very simple step which took me two days to find. :oops:

Rating Comment. I'll try to be objective and rate my walkthrough for V0.9 as if I'd found that very simple step much sooner, so I'll rate it at 1.0.

Walkthrough by Andrew:

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Andrew

Post subject: Archive Part H. Assassins 201-225, variants, other puzzles

Posted: Sun Feb 24, 2013 3:25 am

Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1895
Location: Lethbridge, Alberta, Canada

Assassin 201 V1 by Børge (October 2010) here

Puzzle Diagrams with "udosuk style Killer Cages":

Code: Select, Copy & Paste into solver:

Solution:

+-------+-------+-------+
| 8 4 1 | 3 7 2 | 9 6 5 |
| 7 6 5 | 4 9 8 | 1 2 3 |
| 3 9 2 | 1 6 5 | 7 8 4 |
+-------+-------+-------+
| 1 8 6 | 5 4 9 | 2 3 7 |
| 2 7 4 | 6 1 3 | 8 5 9 |
| 5 3 9 | 2 8 7 | 4 1 6 |
+-------+-------+-------+
| 9 5 7 | 8 3 1 | 6 4 2 |
| 6 1 3 | 9 2 4 | 5 7 8 |
| 4 2 8 | 7 5 6 | 3 9 1 |
+-------+-------+-------+

Quote:

Børge: SS score 1.16

Joe Casey: V1 took me about 45 minutes (with ball-point pen on a paper printout, as usual: I like the pale colours, but if the dotted cage-margins were a bit closer to the cell boundaries it would leave more room for writing the candidates in the corners). I don't do walks-through, but

Hidden Text:

Børge: Joe, Nice to see that you are still around.

Joe Casey wrote:

I like the pale colours, but if the dotted cage-margins were a bit closer to the cell boundaries it would leave more room for writing the candidates in the corners

If you before printing an image on paper scales it 150% in Paint, you should have plenty of space. An image scaled 150% fits on both A4 and Letter. Use 10mm margins when printing on A4.

Joe Casey wrote:

V1 took me about 45 minutes (with ball-point pen on a paper printout)

That's why I made v2, especially for you, with an other cage layout than v1

Should take you considerably longer than 45 minutes. :twisted:

Børge gave a detailed explanation about the diagrams in here, including a link to his earlier post which explains how to access his program.

Ed: Another really high quality cage structure and puzzle. Thanks Børge! Love the 3D effect of the first V2 pic! Looks like Joe-Casey worked in the same area as I did but the way to crack it was very hidden for me (step 6).

HATMAN: I've posted an Old Lace test in the variants section for those of you who have completed any of these.

Andrew: Thanks Børge for a fun pair of cage patterns!
I finished A201 and the V0.9 a few days ago, then had a go at HATMAN's Old Lace Test here before checking my walkthroughs.
Nice walkthrough Ed! We both found our breakthroughs in a similar area but in different ways, Ed's step 6a and my step 20.
Rating Comment. I'll rate my walkthrough for A201 at Hard 1.25.

Andrew:

HATMAN wrote:

I've posted an Old Lace test in the variants section for those of you who have completed any of these.

I can strongly recommend trying this, even if like me you've never done a Windoku puzzle before; the Old Lace Test is a Windoku Killer-X.
Step 2 of Simon's walkthrough (for the Old Lace Test) gets straight to one of the key features of the Old Lace cage pattern. That step could be applied directly to A201 and the V0.9, possibly also for the other cage pattern in the V0.8 and the V2 although it's not immediately obvious what the benefit would be for them.
Simon's step gives most benefit for A201 where in a couple of steps R5C12 and R5C89 can each be reduced to naked pairs.

Walkthrough by Ed:

Walkthrough by Andrew:

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Andrew

Post subject: Archive Part H. Assassins 201-225, variants, other puzzles

Posted: Sun Feb 24, 2013 3:43 am

Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1895
Location: Lethbridge, Alberta, Canada

Assassin 201 V2 by Børge (October 2010) here

Puzzle Diagrams with "udosuk style Killer Cages":

Code: Select, Copy & Paste into solver:

Solution:

+-------+-------+-------+
| 5 3 4 | 2 1 6 | 9 7 8 |
| 7 1 8 | 3 4 9 | 5 2 6 |
| 2 6 9 | 8 7 5 | 4 3 1 |
+-------+-------+-------+
| 9 5 7 | 1 8 4 | 3 6 2 |
| 4 2 6 | 9 3 7 | 8 1 5 |
| 1 8 3 | 5 6 2 | 7 4 9 |
+-------+-------+-------+
| 3 4 5 | 6 9 1 | 2 8 7 |
| 6 7 2 | 4 5 8 | 1 9 3 |
| 8 9 1 | 7 2 3 | 6 5 4 |
+-------+-------+-------+

Quote:

Børge: SS score 2.51

Joe Casey wrote:

V1 took me about 45 minutes (with ball-point pen on a paper printout)

Børge: That's why I made v2, especially for you, with an other cage layout than v1

Should take you considerably longer than 45 minutes. :twisted:

A201 v2 images scaled 150% in Paint:

Joe Casey: It did

Ed: Another really high quality cage structure and puzzle. Thanks Børge! Love the 3D effect of the first V2 pic!

simon_blow_snow: Guess I should post my walkthrough for v2 to complete the series. ;-)

A surprisingly sudden spectacular collapse at the end. :-)

Andrew: Nice solving path, Simon!
My solving path was basically the same as Simon's until the end of his step 9 but I didn't spot his step 10, even though it's the same type of logic as his step 3 (my step 13). I therefore found myself having to work harder, and in a different area of the puzzle, to make my final breakthrough.
Rating Comment. I'll rate my walkthrough for A201 at least Hard 1.5. If I'd found Simon's step 10, then I'd rate it at 1.5.

Walkthrough by simon_blow_snow:

Walkthrough by Andrew:

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Andrew

Post subject: Archive Part H. Assassins 201-225, variants, other puzzles

Posted: Sun Feb 24, 2013 5:07 am

Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1895
Location: Lethbridge, Alberta, Canada

goooders' Special 1 by Børge (October 2010) here

Puzzle Diagrams with "udosuk style Killer Cages":

Code: Select, Copy & Paste into solver:

Solution:

+-------+-------+-------+
| 8 2 6 | 1 4 7 | 3 9 5 |
| 3 4 1 | 2 5 9 | 8 6 7 |
| 9 5 7 | 6 8 3 | 2 4 1 |
+-------+-------+-------+
| 1 3 2 | 7 6 5 | 9 8 4 |
| 7 9 8 | 4 3 1 | 6 5 2 |
| 4 6 5 | 8 9 2 | 7 1 3 |
+-------+-------+-------+
| 2 7 4 | 9 1 6 | 5 3 8 |
| 5 8 9 | 3 7 4 | 1 2 6 |
| 6 1 3 | 5 2 8 | 4 7 9 |
+-------+-------+-------+

Quote:

Børge: Unless there are MASSIVE PROTEST, there will be an upcoming Assassin having puzzles with exactly this cage pattern.
I have 9 puzzles with a good SS score spread from 0.93 through 7.02, which both JSudoku and SudokuSolver can solve.
Have to do some analysis of the puzzles first to select which ones to post.
According to Ed one of the characteristics of a good Assassin is that SudokuSolver can solve it in a blink of an eye, and that JSudoku has a terrible time solving it.
The v1 at 1.40 of the upcoming Assassin has exactly this characteristic.
The following puzzle is the exact opposite. SudokuSolver rates it at 7.02, and JSudoku solves it instantly.
Based on the techniques JSudoku uses, my ballpark figure rating is Hard 1.75.
What does the human solvers say?
EDIT: "The 45 Rule lovers" will hopefully NOT get a raw deal: SudokuSolver uses fifteen 45 rules distributed over nine different 45 rule techniques.

Andrew: I've never downloaded any solver so have no experience of using them. It seems strange to me that one solver can solve puzzles very quickly while the other struggles, even though I've read that one is better at 45s and combination work while the other is better for chains, "fish" and the like.
Don't know whether I'll try that one; it depends whether I find the time and inclination to try it. I welcome puzzles with this cage pattern including the planned v1 with a score of 1.40. Maybe that will be A203? I hope that someone else will claim A202 since Børge posted the A201 puzzles.

Børge: My understandig is as follows:
JSudoku has solvers for X techniques. SodokuSolver has solver for Y techniques.
if you take a ∆X = ∆Y and for both ∆X and ∆Y sort the techniques to be deployed in the same order, I would assume that both solvers will perform somewhat equal for most Killers.
The default sequence of solvers' deployment is however pretty different for the two solvers.
The remaining more detailed comments on the solvers are here

You absolutely should try it.
If you solve it, you can boast about having solved a Killer rated 7.02 by SudokuSolver

Do not think that anyone has ever solved a Killer rated 7.02 by SudokuSolver.

Andrew: Many thanks Børge for persuading me to have a go at this one, after the hard slog of A199V2.

This was a fun puzzle.

I guess I could call it a One (and a half) Trick Pony, step 9a being the main breakthrough and step 18 leading to a much quicker finish.

Børge wrote:

"The 45 Rule lovers" will hopefully NOT get a raw deal: SudokuSolver uses fifteen 45 rules distributed over nine different 45 rule techniques.

I didn't try finding them all. I only used two of them and spotted two others but in those cases immediately found quicker ways (steps 2 and 4) to get better results.
Rating Comment. I'll rate this puzzle at 1.5.

Ed: Love the look of that cage pattern. Look forward to it.
Well done Andrew for taking on this goooders special! The key step SS can't get is your step 4. I've sent it to Richard hoping it's just a bug that can be easily fixed. I know it can do that type of step (grouped X-cycle) at other times so fingers crossed.

Børge: Andrew, Thanks a lot for giving this puzzle a try :sun:

You deserve a place in Guinness Book of World Records for having solved a Killer rated 7.02 by SudokuSolver. :applause:

Børge wrote:

... there will be an upcoming Assassin having puzzles with exactly this cage pattern.

If there is still interest, I will make good on my long due promise.

Andrew: Thanks Børge for your nice comments!

I look forward to your offer of posting an Assassin with this cage pattern. From his post in this thread, I'm sure Ed will look forward to it also. Ed loves puzzles with large cages.
A puzzle with this cage pattern and SSscore of 1.40 should make a good Assassin.

Walkthrough by Andrew:

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Andrew

Post subject: Archive Part H. Assassins 201-225, variants, other puzzles

Posted: Mon Feb 25, 2013 3:56 am

Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1895
Location: Lethbridge, Alberta, Canada

Assassin 202 V0.85 by Børge (October 2010) here

Puzzle Diagrams with "udosuk style Killer Cages":

Code: Select, Copy & Paste into solver:

Solution:

+-------+-------+-------+
| 1 2 6 | 5 4 3 | 8 7 9 |
| 4 3 8 | 9 7 1 | 2 6 5 |
| 5 9 7 | 6 8 2 | 3 4 1 |
+-------+-------+-------+
| 2 5 3 | 4 1 8 | 7 9 6 |
| 8 1 4 | 7 6 9 | 5 3 2 |
| 7 6 9 | 3 2 5 | 1 8 4 |
+-------+-------+-------+
| 6 8 5 | 1 3 4 | 9 2 7 |
| 3 7 1 | 2 9 6 | 4 5 8 |
| 9 4 2 | 8 5 7 | 6 1 3 |
+-------+-------+-------+

Quote:

Børge: SS score 0.85

Andrew: A202 V0.85 started more easily than the V1 but then I really struggled to finish it. I couldn't see any way to make the final breakthrough using steps consistent with the SS score. Maybe someone else can find a way to continue from the position after my step 13 (or step 15) using simple steps.
I even took a break from this puzzle and did a similar number of steps on the V2.
Then I came back to V0.85 and found a nice short way to finish it but this is waaay OTT compared with the SS score.
Rating Comment. I'll rate my walkthrough for A202 V0.85 at Easy 1.5.

Børge: I took a look at the techniques used by SudokuSolver and JSudoku:

Hidden Text:

Andrew:

Thanks Børge for your comments about the steps which SudokuSolver and JSudoku used to solve V0.85:

Frank: Hi Andrew - the way I would proceed from your diagrammed position is: If r1c8 = 8 then you get 2 1's in nonet 6. So r1c8 = 7 and that solves the puzzle.

Børge:

Inside the hidden text two posts above Andrew wrote:

I often use X-Wings; I can't see one in this position.

In this position there is an X-Wing on 1 ◄ Select to see the digit the X-Wing is on.
There is also a Swordfish on the same digit, yielding the exact same eliminations as the X-Wing. :study:

  EDIT

Here an image showing the X-Wing and the Swordfish:

Børge:

After the X-Wing, even I can solve the puzzle using a Y-Wing and simple arithmetic:

Y-Wing on 6 in r2c89 with {16} pincers in (r4c9 + r9c8) -> r6c8<>1 -> r6c8=8 -> r1c8=7 -> r9c8=1 -> r9c7=6 -> r4c7=7
27(4) cage in N3: r1c8+r1c9=16 -> r2c8+r2c9=11 -> r2c8=6 -> r2c9=5
PUZZLE SOLVED: rest is naked singles

  EDIT

At the position in Andrew's diagram the puzzle can be solved without the X-Wing using only a Y-Wing and simple arithmetic:

Y-Wing on 6 in r2c89 with {16} pincers in (r4c9 + r9c8) -> r46c8<>1 -> r6c8=8 -> r1c8=7
27(4) cage in N3: r1c8+r1c9=16 -> r2c8+r2c9=11 -> r2c8=6 -> r2c9=5
PUZZLE SOLVED: rest is naked singles

Perhaps Sudoku-Solver's X-Cycle Simple 2 is a Y-Wing?

In my ratings explained I rate Y-Wing as a Super Hard technique and all Chains as an Ultra Hard technique.

Ed: These puzzles are very different to 99% of killers posted here since they have a hard, interesting ending after many easy placements. Yet for me, still definitely killers, not vanillas, since no X-wings, Y-wings or Swordfish (damn..love all them!! Thanks for showing them Børge [edited after next post].)

(edit2: I'm never opposed to using those techniques and love finding them. Unfortunately, I didn't use any of them. Instead, for both the v0.85 and v1 I used quite tricky killer steps. I would have been very happy to have not found those shortcuts and have found the wings instead. Did the V1 the same way as Andrew (his step 13). Very Assassin step. Took me a long while to find too with lots more little eliminations in other areas first.

V0.85 came out a lot quicker. Closest to Frank's way. BTW, the ALT 5 SS score is 1.00 ◄ Select [edit: Note, in next release of SS with different routine weightings than current version as explained here]

Alt ending to V0.85:

From here

.-------------------------------.-------------------------------.-------------------------------.
| 1         2         6         | 5         3478      348       | 378       3478      9         |
| 45        3         8         | 4679      12467     1249      | 12567     467       56        |
| 45        9         7         | 46        123468    12348     | 123568    13468     1256      |
:-------------------------------+-------------------------------+-------------------------------:
| 2         5         34        | 4679      14678     1489      | 13678     136789    16        |
| 8         1         34        | 4679      2467      2459      | 23567     3679      256       |
| 7         6         9         | 3         128       1258      | 1258      18        4         |
:-------------------------------+-------------------------------+-------------------------------:
| 6         8         5         | 1         34        34        | 9         2         7         |
| 3         7         1         | 2         9         6         | 4         5         8         |
| 9         4         2         | 8         5         7         | 16        16        3         |
'-------------------------------.-------------------------------.-------------------------------'

1. r4c9 = 6 or r6c8 = 8 (can't both be 1) -> {4689} blocked from 27(4)n3 since it can only have 6 in r2c9 and 8 in r1c8
1a. 27(4)n3 = {5679} only -> r2c9 = 5, r12c8 = [76]

Cracked.

Børge:

Ed wrote:

Yet for me, still definitely killers, not vanillas, so no X-wings, Y-wings or Swordfish ...

Why not?
Back in the 70's and 80's when I studied IT, Math, Physics and Statistic we were often required to use only certain techniques to solve a problem. Really stupid if you ask me. Now in everyday life I use whatever means and techniques I know and master to get a problem solved the best possible way using as little time as possible. That's what counts and makes the bucks. No point in spending 40 hours to solve a problem using only techniques from set A when you can solve it in 25 hours using different or additional techniques.

Ed wrote:

BTW, the ALT 5 SS score is 1.00 ◄ Select

You are wrong! it is 0.10 lower!

(Archive Note) A long and interesting discussion, partly triggered because I missed a step I ought to have seen.
More discussion of puzzle types follows in the next archive entry.

Walkthrough by Andrew:

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Andrew

Post subject: Archive Part H. Assassins 201-225, variants, other puzzles

Posted: Wed Feb 27, 2013 10:00 pm

Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1895
Location: Lethbridge, Alberta, Canada

Assassin 202 V1 by Børge (October 2010) here

Puzzle Diagrams with "udosuk style Killer Cages":

Code: Select, Copy & Paste into solver:

Solution:

+-------+-------+-------+
| 7 9 2 | 3 6 4 | 5 1 8 |
| 6 3 8 | 7 5 1 | 4 9 2 |
| 5 1 4 | 8 2 9 | 7 3 6 |
+-------+-------+-------+
| 4 7 9 | 1 3 6 | 8 2 5 |
| 3 5 6 | 2 7 8 | 9 4 1 |
| 2 8 1 | 9 4 5 | 3 6 7 |
+-------+-------+-------+
| 9 2 3 | 5 1 7 | 6 8 4 |
| 8 4 5 | 6 9 2 | 1 7 3 |
| 1 6 7 | 4 8 3 | 2 5 9 |
+-------+-------+-------+

Quote:

Børge: SS score 1.18

Andrew: Thanks Børge for an interesting cage pattern. It seems designed to give some early results, even for the V2 which I haven't yet tried, followed by some harder work later.
Rating Comment. Easy 1.25.

Joe Casey: Did the V1 - nothing new to report: munched through it steadily at first, but N3 and the outermost 45 turned out to be very gristly.
I like to feel we're having to think of something original to solve a puzzle - it's a puzzle, not maths homework - and also I want to feel as if I'm discovering something new, not just following a path set by someone who's been here before (like my motto).

Børge: My interpretation of your comment is that the puzzle was below average and not particularly to your liking. Sorry about that.

Joe Casey: And by the way, no need to put up extra-large pictures on my account: being Scottish, and Scottish thrift is legendary, I print two puzzles to an A4 page whenever possible (KSO pdf pics excepted).

Børge: Thanks for this information. After your first post in the Assassin 201 thread, asking for more space for or writing the candidates in the corners, I decided to add 150% scaled extra-large pictures. If no one else comes forwards and say that they want them, I will discontinue them.

Joe Casey: No, I wouldn't describe them as below average. They felt original, having to think for oneself and invent stuff, which is good (though maybe subjective); a bit on the hard side of 'comfortable', and not a style I'd like regularly. But I'm not really into stipulating what puzzles are set. Setters choose, and solvers hope for a variety of challenges. I pick the website/newspaper with the sort that suits.
Also: I'm up for one assassin per week, and not greedy for lots of souped-up versions, so I may not let you provoke me into attempting them all in future. Thanks anyway.
And as for Xs and Ys and fish: I'm not against them in principle; I've looked them up and just about understand them; but hardly ever see the opportunity to apply them in puzzles. And if I did, it would be more like maths homework.

Børge: Thanks for the feedback.
What style do you like?

Large cages.
Small cages.
Diagonal cages.
Disjoint cages.
Zero killer.
Combination of two or more of the above.

When I post more than one version for an Assassin it is manly to try to give people with different solving experiences and skills a treat.
I do not expect anyone to try more than one of the versions, although as you have correctly observed, often tries to provoke the regulars into trying several of them.

I also want to have some fun. 8-)

And I really enjoy feedback, and ANY KIND of feedback. One of the main functions of a forum is discussions and the interaction with others.
That's what makes it more fun for me to make Killer Sudoku puzzles than standard gattai puzzles.
I might be wrong, but my impressions is that some of the "big guns" sometimes wants to hone them self and try a really difficult puzzle.
The way I make an Assassin normally produce a lot of puzzles ranging from very easy (SS score 0.60) through absolutely unsolvable (SS score 15.00).
It is therefore very tempting to post them all. It hurts to throw away puzzles.

Joe Casey: What style? Any of these, in any combination, and any others we haven't thought of yet. I value variety, originality and surprises, and my preference is to express no preference.
I think you're right to offer a range of difficulty levels on the same theme (not that you're under any obligation to produce any puzzles at all); sometimes I'm in doubt as to which one to try: usually it'll be the first one rated at over 1.0, which I understand to be traditional Assassin level; but as we know the ratings don't always correspond to subjective difficulty.

Andrew: An interesting discussion between Børge and Joe Casey in the last 24 hours.
I like most style of cage patterns, including combinations of the various types listed in Børge's list. One thing not mentioned is that Killer-Xs can go with any of the listed types. Zero Killers are a fairly recent addition to Assassins although they have been around for some time on this site, for example in most/all of HATMAN's puzzles. I've come to enjoy Zeroes, which often bring a different approach to solving.
My preference is for more puzzles with "normal" cages, whether those be large or small, regular or irregular ones and fewer puzzles with diagonal or disjoint cages which tend to give far fewer 45s to work with; diagonal cages within a nonet aren't so bad, they are probably no worse than L-shaped or irregular cages in removing 45s.
Puzzles which require a lot of detailed combination and permutation analysis can be very tedious.
I don't think that I'm one of the "big guns"; most of the people I consider to be in that group aren't active on this site at the moment. I tend to try to solve all posted puzzles "because they are there", to use the proverbial reason for people climbing mountains, and I try to post walkthroughs for the easier puzzles because they may be helpful to Newbies; some of those walkthroughs get linked from my Advice "sticky". As a retired person I've also got more time to work on puzzes, while I'm listening to internet radio which allows me to listen to the BBC even though we retired to Canada. However there can be too many variants on a theme at times; I feel that a maximum of three is reasonable.
As a minimum I try to solve every V1 Assassin but I've still got quite a lot of unfinished harder puzzles, and some not even started, in my Unfinished folders for this site and for Ruud's site.

Walkthrough by Andrew:

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Andrew

Post subject: Archive Part H. Assassins 201-225, variants, other puzzles

Posted: Wed Feb 27, 2013 10:10 pm

Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1895
Location: Lethbridge, Alberta, Canada

Assassin 202 V2 by Børge (October 2010) here

Puzzle Diagrams with "udosuk style Killer Cages":

Code: Select, Copy & Paste into solver:

Solution:

+-------+-------+-------+
| 9 4 3 | 6 5 7 | 1 2 8 |
| 6 2 8 | 4 1 3 | 7 9 5 |
| 5 1 7 | 2 8 9 | 6 4 3 |
+-------+-------+-------+
| 7 3 6 | 1 9 2 | 5 8 4 |
| 1 5 9 | 8 3 4 | 2 6 7 |
| 2 8 4 | 5 7 6 | 9 3 1 |
+-------+-------+-------+
| 4 6 1 | 3 2 5 | 8 7 9 |
| 8 7 2 | 9 4 1 | 3 5 6 |
| 3 9 5 | 7 6 8 | 4 1 2 |
+-------+-------+-------+

Quote:

Børge: SS score 1.82

Joe Casey: Haven't tried V2.

PS done V2 now: same deal as V1.

Hidden Text:

Andrew: The V2 was a really tough one. After an interesting start I had to resort to chainy combination/permutation analysis so found myself doing what I'll call "solution by attrition".
Rating Comment. I agree with the SS score. My walkthrough was definitely in 1.75 territory.
Congratulations to Joe Casey for solving this V2 with paper and pencil. :applause:

I used coloured candidates on my worksheet to keep track of the analysis which I was doing and, even then, found I had to re-work part of one sub-step when I checked my walkthrough before posting it.

Walkthrough by Andrew:

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