Assassin 85 (Original Version)

Nasenbaer · Post by **Nasenbaer** » Thu Jan 17, 2008 1:12 am

A last one before bedtime.

53. checking placement in 13(3) @ r3c3: no 1 in r4c3

54. 17(3) @ r3c6: {269} and {368} removed, can't be placed

Andrew · Post by **Andrew** » Thu Jan 17, 2008 5:01 am

Three more steps including my first contradiction moves for this puzzle and the first eliminations from R6C8, the last cell that had all candidates.

55. R8C159 = [198/567/648] (step 39), R28C34 = [1784/2738/2765/2783/5438/5465/5483/5735] (step 44c, modified by step 47b)
55a. Killer pair 5,8 in R8C159 and R8C34, locked for R8

56. 23(5) cage at R6C8 must contain 5 (step 37) = {12569/13568/14567/23459/23567} ({12578} was eliminated in step 28c)
56a. Cannot be {13568}, here’s how
{13568} => R6C8 = 8, R7C8 = 5, R8C678 = {136}, R8C34 = [84] (step 55) -> no remaining combinations in R89C5
56b. 23(5) cage at R6C8 = {12569/14567/23459/23567}, no 8

57. 2 in C6 must be in R7C6 or R8C6
57a. If 23(5) cage at R6C8 = {14567} => R7C6 = 2, R67C7 = [71], R8C78 = {46}, naked pair {46} in R8C78 clashes with R9C7 -> cannot be {14567}
57b. 23(5) cage at R6C8 = {12569/23459/23567}
57c. If {23567} => R6C8 + R8C6 = {27}, R7C8 = 5, R8C78 = {36}, R8C159 = [198] (step 55), R9C8 = 7 -> no 7 in R6C8

Andrew · Post by **Andrew** » Thu Jan 17, 2008 6:54 am

And one more step for tonight.

58. Hidden killer pair 4,7 in R2C4 and R2C678 for R2 -> R2C678 must contain 4/7
58a. 24(5) at R2C6 (step 36c) = {12489/12678/23478}
58b. 4 of {12489} must be in R2C678
58c. 3 of {23478} must be in R4C8
58d. -> no 4 in R4C8 (taking steps 58b and 58c together)

There's also another hidden killer pair 7,8 in R23C8 and R9C8 -> R23C8 must contain 7/8 but I haven't yet been able to use it.

Andrew · Post by **Andrew** » Thu Jan 17, 2008 7:29 am

Then I had one more look before shutting down my computer for the night.

59. 45 rule on C89 4 outies R2C67 + R8C67 = 14 = [1229/1436/1724/1823/4226/7223] (cannot be [1274/1814/1841/4271/7214/7241/8213/8231] which clash with the 23(5) cage, cannot be [4721/7421] which clash with R2C4)
59a. -> no 8 in R2C6, no 1,4,7,9 in R8C6, no 1 in R8C7
59b. 23(5) cage at R6C8 = {12569/23459}

Can you guys please check that I got the permutations right, and haven't missed any, before continuing with new steps? If this step is correct it's a major candidate reduction in R8C6.

Afmob · Post by **Afmob** » Thu Jan 17, 2008 8:45 am

Great work from all of you! I can verify Andrew's combo eliminations for Outies C89 and there is even one combo he has mentioned that isn't possible which leads to another placement

.

60. Outies C89 = 14(2+2) = [1229/1724/1823/4226/4721/7223/7421]
- [1436] impossible because 7 of 23(5) only possible @ R8C6 and R8C67 = [36] forces 23(5) = {23567}
60a. R8C6 = 2
60b. 23(5) = 259{16/34}
60c. 10(3) @ R6C7: R6C7 <> 7 because 2 only possible there

61. 8 locked in R45C7 for C7

62. 9 locked in R789C5 for C5

63. Hidden Single: R2C8 = 8 @ R2
63b. R9C8 = 7, R8C9 = 8
63c. 13(2) @ C9 = {49} locked for C9
63d. 12(2) @ C9 = [75]
63e. 5(2): R5C8 <> 1

The assassin is cracked and should be solvable by now

.

mhparker · Post by **mhparker** » Thu Jan 17, 2008 10:30 am

Let the mop-up begin...

64. R6C8 = 5 (HS@C8); R8C2 = 7 (HS@R8); R4C1 = 7 (HS@C1/N4)
64a. ->R3C1 = 3

65. Split 10(2) at R8C15 = [19/64]
65a. -> no 5 in R8C1, no 6 in R8C5

66. R9C1 = 5 (HS@15(3))
66a. cleanup: no 4 in R9C37

67. Split 16(3) at R7C8+R8C78 (steps 59b, 60b) = {349} (no 1,6), locked for N9
(Note: {169} blocked by R9C7)
67a. R8C78 cannot contain both of {49} due to R8C5
67b. -> 3 locked in R8C78 for R8 and split 16(3)

68. NS at R8C3 = 6
68a. cleanup: no 4 in R6C1, no 3 in R9C4

Rest is just singles and simple cage sums now.

8 4 7 9 2 6 5 1 3
9 2 5 4 3 1 7 8 6
3 6 1 8 7 5 9 2 4
7 1 4 2 5 8 3 6 9
2 5 3 7 6 9 8 4 1
6 8 9 3 1 4 2 5 7
4 3 2 6 8 7 1 9 5
1 7 6 5 9 2 4 3 8
5 9 8 1 4 3 6 7 2

Great team effort. Thanks to everybody.

Nasenbaer · Post by **Nasenbaer** » Thu Jan 17, 2008 1:34 pm

Well, it's done. While I worked through Andrews steps the rest of the team solved it. Great work!

Here are some comments:

Andrew, you should have included the following step (Afmob used it as step 61):
56c. 8 locked in r45c7 for n6 and c7

This step would have reduced step 59 a little.

Now to step 59. I made a small table for all the possibilities and the reason why the combination is not possible. New step 56c included!

Code: Select all

outies c89 = 14&#40;2+2&#41;
r2c67 r8c67 reason why not possible
-----------------------------------
12    29    r2c23=5&#123;1|2&#125; &#40;Andrew missed that one, it removes 9 from r8c7&#41;
12    74    r2c23=5&#123;1|2&#125; and 23&#40;5&#41;
14    36
17    24
18    14    r28c6 and new step 56c
18    23    new step 56c
18    41    23&#40;5&#41; and new step 56c
42    26
42    71    23&#40;5&#41;
47    21    r2c4
72    14    23&#40;5&#41;
72    23
72    41    23&#40;5&#41;
74    21    r2c4
82    13    23&#40;5&#41;
82    31    23&#40;5&#41;

So now it would have been r2c8 = 8 -> r9c8 = 7 -> r8c9 = 8 ...

Again, great work! It's been a long time since I did a tag, I really missed it!

Andrew · Post by **Andrew** » Thu Jan 17, 2008 10:28 pm

Thanks to Nasenbaer for pointing out that I missed what should have been step 56c and that I should have eliminated [1229] from step 59.

Thanks to Afmob for pointing out that I could also have eliminated [1436] from step 59. That one isn't quite so obvious at that stage; it is a valid elimination then. It is easier to see after step 59b when it clashes with the remaining combos for 23(5).

My steps 58 and 59 were posted just before and just after midnight. If it had been a bit earlier I might have spotted those extra eliminations and been able to finish the puzzle. That's what happens when it's late at the end of a long session. It happened earlier when I spotted steps 29 and 30 after Nasenbaer had a long session.

It seems quite a long time since we've had a "tag". The last one I can remember was started by Cathy and involved more forum members than any other "tag". That was one where some steps came so quickly that I was never able to catch up and add any moves but I then wrote the consolidated walkthrough.

I won't be writing a consolidated walkthrough this time. This "tag" solution flowed well so it doesn't need one. Ed can link to the start of this thread when he adds it to the rating "sticky".

Mike wrote:2.0: Traditional "V2" standard, typically requiring a team effort and maybe (but not necessarily) involving limited use of hypotheticals. Example: A55V2.

2.5: Requires a team effort and several short to medium length hypotheticals. The TJK18 and A48-Hevvie would probably fall into this category.

3.0: "Ruudiculous", requiring a team effort and massive hypotheticals to solve, if it can be solved at all. The A50V2 and (possibly) A60RP could be considered examples of this.

Looking at those rating definitions I think we have just finished a puzzle rated at 2.5. It definitely required a team effort and we used a fair number of contradiction moves as well as Mike's AIC in step 40. I don't think we quite reached massive hypotheticals although some of the contradiction moves were quite complicated and I was amazed that some of them could be spotted.

Afmob · Post by **Afmob** » Fri Jan 18, 2008 7:12 am

I'll agree with the rating of 2.5 because of the size of some of the chains we used.
The definition of the rating above rating 2.0 about requiring a team effort is not necessarily true, e.g. my walkthrough for A60RP, but you need a lot of time to do this so with team effort it needs less time to solve because of the different ideas everybody participating has.

Apart from the last steps before finally cracking A85 (original version) this walkthrough is in the right order so a shortened walkthrough is probably not needed (but might be appreciated).