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The original puzzle with this cage pattern got a score of 1.25, but then I realized the (1.5 rating) way I solved it was wrong. Couldn't find any way to finish it! So, went for this lower score one but haven't had time to finish it but it's not a pushover [edit: Finished now. Estimated rating Easy 1.5 with some tricky combo work. But with 3 walk-throughs the first day and Afmob's rating....hmm...time to read!]. My apologies if it's too hard for an Assassin.

SS might be using the same sort of move to solve both and it's just eluding me. I'll post the other one as a V2 if the breakthough move is different to what you guys find for this one. Might post it anyway. Found a new move, IOE. More on that later.

Assassin 144

SS(v3.3.0)score 1.10

Hoping
Ed

Thanks Ed! Lots of nonets you had to combine to find the hidden cages, but it was fun to solve nonetheless.

A144 Walkthrough:

1. C6789
a) 35(6) = 89{1467/2367/2457/3456} -> CPE: R4C9 <> 8,9
b) Outies N3 = 10(2) <> 1,5; R4C8 <> 2
c) Outies N36 = 12(2) <> 1,2,6
d) 12(3): R6C78 <> 9 since R7C8 >= 3
e) 9 locked in 35(6) @ N6 for 35(6)
f) Outies N36 = 12(2): R7C8 <> 3
g) 11(3): R3C78 <> 8 since R4C8 >= 3
h) 12(3): R6C78 <> 8 since R7C8 >= 4

2. C1234 !
a) Outies N7 = 10(2) <> 5; R6C1 <> 1
b) Outies N47 = 14(2) = {59/68}
c) ! 28(6) = 3{12589/12679/14569/24568} because 47{1259/1268/1358} blocked by Killer pair (47) of 21(3)
-> 3 locked for N4
d) Outies N7 = 10(2) <> 7

3. N35689
a) Innies N3689 = 14(2) = {59/68}
b) Outies N35689 = 6(2) = {15/24}
c) 11(3) <> 8 since {12}8 blocked by Killer pair (12) of Outies N35689
d) Outies N3 = 10(2) <> 2
e) 8 locked in 35(6) @ N6 for 35(6)
f) Outies N36 = 12(2): R7C8 <> 4
g) 12(3) @ N6: R6C78 <> 5,7 because R7C8 >= 5 and R7C8 <> 6
h) 5 locked in 35(6) @ N6 for 35(6) -> 35(6) = 4589{27/36} -> CPE: R4C9 <> 4
i) 1 locked in 12(3) @ N6 for R6

4. R456 !
a) Outies N7 = 10(2) <> 9
b) 1 locked in 28(6) @ N4 = 139{258/267/456}
c) ! Killer pair (24) locked in 28(6) + Outies N7 for N4
d) 21(3) = 7{59/68} -> 7 locked for R4+N4
e) Outies N3 = 10(2) = {46} -> R4C9 = 6, R4C8 = 4
f) 35(6) = {245789} -> R7C9 = 4; 2 locked for N6
g) 12(3) = {138} -> R7C8 = 8; 1,3 locked for R6

5. C789
a) 6 locked in 11(3) @ N3 = {146} -> 1,6 locked for R3+N6
b) 1 locked in 8(2) @ C9 = {17} locked for C9+N9
c) 35(6) = {245789} -> 7 locked for R5

6. R3456
a) Outies N47 = 14(2) = {59} locked for R3+N1
b) 31(6) = {234589} since R3C34 = (24) -> 2,4 locked for R3+31(6); {3589} locked for N5
c) 9(2) = {27} -> R5C4 = 2, R6C4 = 7
d) 25(5) = {14569} -> R5C5 = 1; {46} locked for R6+25(5); {59} locked for R7
e) R3C4 = 4, R3C3 = 2

7. R789
a) 12(3) = 1{38/56} -> 1 locked for C4+N8
b) 15(4) = {2346} -> R9C6 = 4; {236} locked for N9
c) 12(2) <> 8
d) 8 locked in 32(6) @ N7 for 32(6)
e) R6C1 = 2, R6C2 = 8
f) 11(3) = {128} -> R7C3 = 1, R7C2 = 2

8. C123
a) Hidden Single: R4C1 = 1 @ R4
b) 7(2) = {34} locked for C1+N1
c) 28(5) = 268{39/57} -> 2 locked for C5+N2

9. C456
a) R6C6 = 6
b) 16(3) = 8{17/35} -> 8 locked for C6+N2
c) 28(5) = 268{39/57} -> R2C3 = 8
d) Innie N2 = R1C4 = 5
e) 12(3) = {138} -> R7C4 = 3; 8 locked for C4+N8

10. Rest is singles.

Rating: 1.0 - Hard 1.0. I used Killer pairs.

After a longer period of no-sudoku this was a good puzzle to find the way back. Hopefully I'll find the time to contribute a new puzzle in a couple of weeks (after I've solved some older ones).

Here's my walkthrough, the way I did it, so it's not very orderly.

Walkthrough Assassin 144
0. Preleminaries
0a. 7(2) @ r1c1 = {16|25|34} -> no 7,8,9
0b. 12(2) @ r1c8 = {39|48|57} -> no 1,2,6
0c. 12(2) @ r9c1 = {39|48|57} -> no 1,2,6
0d. 21(3) @ r3c2 = {489|579|678} -> no 1,2,3
0e. 11(3) @ r3c7 = {128|137|146|236|245} -> no 9
0f. 11(3) @ r6c2 = {128|137|146|236|245} -> no 9
0g. 9(2) @ r5c4 = {18|27|36|45} -> no 9
0h. 8(2) @ r8c9 = {17|26|35} -> no 4,8,9

1. 8,9 locked in 35(6) @ r4c7 -> no 8,9 in r4c9

2. 45 on n7: r6c12 = h10(2) = {28|37|46}|[91] -> no 5, no 1 in r6c1

3. 45 on n47: r3c12 = h14(2) = {59|68} -> no 1,2,3,4,7

4. 45 on n3: r4c89 = h10(2) = {37|46}|[82] -> no 1,5, no 2 in r4c8
4a. 11(3) @ r3c7: no 8 in r3c78

5. 45 on n36: r7c89 = h12(2) = {39|48|57} -> no 1,2,6

6. 45 on c4: r1234c4 = h24(4)

7. 45 on c789 (2 innies, 1 outie): r78c7 = r9c6 + 10 -> no 8,9 in r9c6, no 1 in r78c7

8. 45 on n2 (1 outie, 2 innies): r2c3 = r13c4 + 1 -> no 1 in r2c3

9. 45 on n3689: r7c67 = h14(2) = {59|68} -> no 1,2,3,4,7
9a. -> r5c5 r6c56 = h11(3) = {128|137|146|236|245} -> no 9
9b. r7: 8 locked in h14(2) and h12(2) for r7

10. 45 on n1247: r3c34 = h6(2) = {15|24} -> no 3,6,7,8,9
10a. -> 9 locked in h25(4) = 9{178|268|358|367} -> no 4

11. 11(3) @ r3c7: {128|245} removed, blocked by h6(2) @ r3c3 -> no 8 in r4c8, no 4,5 in r3c78
11a. -> h10(2) @ r4c8: no 2 in r4c9
11b. r3: 1,2 locked in h6(2) and r3c78 for r3

12. 32(6) @ r1c7: {125789 removed, blocked by 11(3)

13. r4: 4,7 locked in r4c23 and h10(2) for r4

14. 12(3) @ r6c7: no 9 in r6c78
14a. -> 9 locked in n6 for 35(6) -> no 9 in r7c9
14b. -> h12(2) @ r7c8: no 3 in r7c8
14c. -> 12(3) @ r6c7: no 8 in r6c78
14d. -> 8 locked in n6 for 35(6) -> no 8 in r7c9
14e. -> h12(2) @ r7c8: no 4 in r7c8
14f. -> 12(3) @ r6c7: no 5,7 in r6c78
14g. -> 12(3) @ r6c7: {345} removed, blocked by h10(2) @ r4c8
14h. 5 locked in n6 for 35(6) -> 35(6) = 4589{27|36} -> no 1, no 5 in r7c9, no 4 in r4c9
14i. -> no 6 in r4c8, no 7 in r7c8
14j. -> 12(3) @ r6c7: no 4 in r6c78, 1 locked in r6c78 for r6
14k. -> no 9 in r6c1, no 8 in r5c4

15. 1 locked in n4 for 28(6) -> {234568} removed

16. 11(3) @ r3c7: {236} removed -> 1 locked in r3c78 for r3 and n3

17. h6(2) @ r3c3 = {24} -> 2,4 locked for r3 and 31(6)
17a. -> h25(5) @ r4c4: {2689} removed
17b. -> h11(3) @ r5c5: {137} removed, blocked by h25(4) -> no 7

18. 12(3) @ r7c4: {246} removed blocked by r3c3

19. c9: 1 locked in 8(2) @ r8c9 -> 8(2) = {17} -> 1,7 locked for c9
19a. -> h12(2) @ r7c8: no 5
19b. -> 12(3) @ r6c7: no 6 in r6c78
19c. -> r7: 8,9 locked in h14(2) and r7c8 for r7
19d. -> h10(2) @ r4c8: no 3 in r4c8
19e. -> 11(3) @ r3c7: no 7 in r3c78
19f. -> 12(2) @ r1c8: no 5 in r1c8

20. 15(4) @ r8c8: 17{25|34} removed, blocked by r9c9 -> no 7

21. h24(4) @ r1c4: no 1

22. 45 on n2 (2 innies, 1 outie): no 2,3 in r2c3, no 9 in r1c4

23. 45 on c1234 (3 innies r2c34 r4c4): h23(2+1) = [959]|[878]|{689}
-> no 4,5,7 in r2c3, no 3,5 in r4c4, no 2,3,4 in r2c4
23a. -> 9 locked in h14(2) @ r3c1 and r2c3 for n1 (-> no 9 in r3c5)
23b. -> no 9 in 19(4) @ r1c2, 7 locked in 19(4) for n1
23c. -> from step 22: no 2,4 in r1c4

24. 19(4) @ r1c2: {2467} removed, blocked by r3c3 -> no 2

25. h10(2) @ r4c8: [73] removed, blocked by 35(6) -> h10(2) = [46]
25a. -> r3c78 = {16} -> 1,6 locked for r3 and n3
25b. -> h14(2) @ r3c1 = {59} -> 5,9 locked for r3 and n1
25c. -> r7c89 = [84]
25d. -> r6c78 = {13} -> 1,3 locked for r6 and n6
25e. -> h14(2) @ r7c6 = {59} -> 5,9 locked for r7 and 25(5)
25f. -> h11(3) @ r5c5: no 2,4,6,8 in r5c5
25g. -> no 2 in r12c1
25h. -> 10(2) @ r6c1 = {28|46} -> no 3,7
25i. -> 21(3) @ r3c2 = {579} -> 7 locked in r4c23 for r4 and n4
25j. -> 11(3) @ r6c2: {245|137} removed -> no 7
25k. -> {2468} locked in r6c1256 for r6
25l. -> r56c4 = [27], r3c34 = [24]
25m. -> no 8 in r1c9

26. 7 locked in r3c56 for r3 and n2

27. {59} locked in r3c1 r6c3 for 28(6)

28. 12(3) @ r7c4 = 1{38|56} -> 1 locked for c4 and n8, no 9
28a. -> 15(4) @ r8c8 = {2346} -> r9c6 = 4, r8c8 r9c78 = {236} -> 2,3,6 locked for n9
28b. -> {59} locked in r78c7 for c7
28c. -> r4c7 = 2, r2c9 = 2
28d. -> h10(2) @ r6c1 = {28}
28e. -> r6c56 = [46], r5c5 = 1
28f. -> r4c1 = 1, r12c1 = {34}, r5c1 = 6
28g. -> 12(2) @ r9c1 = {57}|[93]

29. 16(3) @ r1c6 = {178} -> r3c6 = 7, r12c6 = {18} -> 1,8 locked for c6
29a. -> r3c5 = 3, r3c9 = 8

30. {1236} locked in r3689c8 for c8
30a. -> {59} locked in r56c9 for c9 and n6
30b. -> r5c78 = [87], r1c89 = [93], r2c8 = 5, r12c1 = [43], r12c7 = [74]
30c. -> r2c45 = {69} -> r2c3 = 8, r1c45 = [52], r12c6 = [81], r2c2 = 7

Rating: I'm a little rusty, so no rating from me.

This puzzle seems to bring about much activity ! Very enjoyable puzzle Ed ! I like all these hidden cages !
I think this killer seems quite difficult to solve for a human because the path is not direct, but I did not have to use technical moves (which explains may be SSscore) : locked candidates, combinations, naked subsets and simple cage blockers.

EDIT : I have made further explanations for step 2

ASSASSIN 144 WALKTHROUGH

1.Hidden cages
a. Outies at n7 : r6c12 total 10 no 5
b. Innies at n1247 : r3c34 total 6 no 36789
c. Outies at n5 : r7c67 total 14 no 12347
d. Outies at n3 : r4c89 total 10 no 5
e. Outies n36 : r7c89 total 12 no 126
f. Outies at n47 : r3c12 total 14 no 12347
g. Innies at c1234 using hidden cage 6(2) at r3c34 : r2c34 + r4c4 total 23 : combinations :
6{89} / [797] / 8{69} / [878] / [959] / 9{68}

2.C789
a. IO for n36 : r7c9 = r6c7+r6c8 → r7c9 different of both r6c7 and r6c8 → r7c9=r4c8
b. r4c8<>9, and r4c8<>8 since r3c78 ={12} blocks combinations of hidden cage 6(2) at r3c23.
c.We have r7c9=r4c8=(347) : r4c89 r7c89 = [3793] / [4684] / [7357]
d. r4c89 r7c89 = [3793] → r6c78 = {12}
r4c89 r7c89 = [4684] → r6c78= {13}
r4c89 r7c89 = [7357] → r6c78= {16} ({25} impossible since r7c8 would be 5 and {34} is blocked by combinations of r4c89)
→ 1 locked for n6 and r6
e. If r4c9=6, r3c78 must contain 6 (nowhere else at n3). Let us see combinations of r3c78
r3c78 = {17} / {26} if r4c89 r7c89 = [3793] (no {35} since r4c8=3)
r3c78={16} if r4c89 r7c89 = [4684] (no {25} which would block cage 6(2) at r3)
r3c78={13} if r4c89 r7c89 = [7357].
But {26} is impossible it would block both hidden cages 14(2) and 6(2) of r3 → 1 is locked for n3 and r3 at r3c78.
f. 1 is locked for c9 at cage 8(2) : r89c9={17} locked for c9/n9 and r4c8<>7
→ r3c34 ={24} locked for r3 and the rest of cage 31(6)
r4c89r7c89=[4684] (since there is no 7 at cells r4c89 and r7c9)
r6c78={13} locked for r6 and n6
- r3c78={16} locked for r3 and n3
r3c12={59} locked for r3 and n1
r7c67={59} locked for r7 and the rest of cage 25(5)

3. N12
a. Cage 21(3)={579} (last combination)
b. 7 locked for r4 and n4 at r4c23 → r4c4<>7 → r2c3<>7 (step 1.g)
c. 7 locked for n1 in cage 19(4) → r1c4<>7
d. IO for n1 : r1c4 +5 = r2c3+r3c3. r2c3={68} and r3c3={24} → r1c4={35} (no 7 (step 3.c))
e. R23c3 cannot be [84] because r1c4<>7 and r23c3 cannot be {64} because it would block combinations of cage 7(2) = {16} {34} → r3c3=2 r3c4=4.

4.N5
a. No 5 in n5 in cages 9(2) (r3c3=4) and in cage 25(5) (r7c67 contain 5) → digit 5 locked for n5 in cage 31(6).
b. Cage 31(6) contains all of {245} → cage 31(6) = {234589} → r4c56={3589} and r5c6 = {3589}
c. Naked subset of size 5 {35789} locked for r4 at r4c23456 → {38} locked for r4 and n5 at r4c456 → No 3/8 at r5c6. r5c6={59}
d. Naked singles for r4 : r4c7=2 r4c1=1
e. Cage 7(2) at c1 = {34} → 3 4 locked for c1 and n1
f. Cage 9(2) at n5 ={27} → 2 7 locked for c4 and n5.
g. Cage 25(5) at n5 = {146}{59} → r5c5=1 and r6c56={46} locked for r6

5.C456 N4
a. Hidden cage 10(2) at r6c12={28} (last combination) locked for r6/n4 → r56c4=[27]
b. Naked pair {59} for r6 locked at r6c39 and naked triple {579} locked for n4 at r4c23 and r6c3
c. r5c1 =6 (naked single) r5c23={34}
d. Digit 1 locked for n2 in cage 16(3). Combination {196} for cage 16(3) blocked by the naked pair {59} locked at r57c6 → r123c6={178} locked for c6 and n2.
e. R4c6=3 (naked single) Naked triple {246} locked for c6 at r689c6.

6.C6789
a. Digit 2 locked for n9 and c8 at r89c8
→ r9c6<>2 r2c9=2 (hidden single for n3) r1c5=2 (hidden single for n2)
b. r9c6<>6 since {14} at r79c9 would block all combinations for cage 15(4) → r9c6=4
r8c6=2 r6c6=6 (all naked singles)
c. Hidden single for r3 : r3c6=7 (I should have seen it earlier) → r12c6={18}
d. Last combination for cage 15(4) at n89 :{2346} with r9c6=4 (step 6b.) and {236} locked for n9.

7.a. Naked singles : r3c5=3 r3c9=8 r1c4=5
b. R2c3=8 (IO for n1 :step 3d)
c. Step 1.g → r24c4 cannot be [78] (r6c4=7) so r24c4 =[69]
d. Last combination : Cage 12(2) in n3-> r1c89={39} locked for n3/r1
e.r12c1=[43] r123c6=[817]
f. r5c7=8 (hidden single in n6) r5c8=7 (hidden single in n6) r56c9={59} locked for c9
g. Cage 12(2) at r1 : r1c89=[93]
h. naked pair {57} at r4c23 locked for r4/r3c2 → r3c2=9=r6c3.
i. NS : r5c6=5, r4c5=8, r7c67=[95], r8c7=9
j. Hidden singles for r9 : r9c1=9 (→ r9c2=3), r9c4=8


Rest is singles.


Edit : It was lacking steps 7h and 7i for stating step 7j; thanks Andrew !

Thanks Ed for an interesting puzzle.

Three very different walkthroughs already posted but I think my one is different enough to post it as well.

I'll rate A144 at Easy 1.25 because I used a killer triple and some split cages.

Here is my walkthrough. After an easy start I slowed right down until I decided in step 18 to look at the 28(6) cage at R3C1 which didn't seem promising even though 1 was locked in it. After that it was easy although my mop-up took a lot of steps.

Prelims

a) R12C1 = {16/25/34}, no 7,8,9
b) R1C89 = {39/48/57}, no 1,2,6
c) R56C4 = {18/27/36/45}, no 9
d) R89C9 = {17/26/35}, no 4,8,9
e) R9C12 = {39/48/57}, no 1,2,6
f) 21(3) cage at R3C2 = {489/579/678}, no 1,2,3
g) 11(3) cage at R3C7 = {128/137/146/236/245}, no 9
h) 11(3) cage at R6C2 = {128/137/146/236/245}, no 9
i) 35(6) cage at R4C7 = {146789/236789/245789/345689}, CPE no 8,9 in R4C9

1. 45 rule on N3 2 outies R4C89 = 10 = {37/46}/[82], no 1,5, no 2 in R4C8

2. 45 rule on N7 2 outies R6C12 = 10 = {28/37/46}/[91], no 5, no 1 in R6C1

3. 45 rule on N36 2 outies R7C89 = 12 = {39/48/57}, no 1,2,6
3a. 45 rule on N36 1 outie R7C9 = 2 innies R6C78
3b. Max R6C78 = 9, no 9

4. 45 rule on N47 2 outies R3C12 = 14 = {59/68}

5. 45 rule on N1247 2 innies R3C34 = 6 = {15/24}

6. 45 rule on N3689 2 innies R7C67 = 14 = {59/68}
6a. R7C67 = 14 -> R5C5 + R6C56 = 11 = {128/137/146/236/245}, no 9
6b. R3C34 = 6 (step 5) -> R4C456 + R5C6 = 25 and must contain 9 = {1789/2689/3589/3679} (cannot be {4579} which clashes with R3C34), no 4

7. 45 rule on N89 4 innies R7C6789 = 26 = {3689/4589/5678} (cannot be {4679} which clashes with R7C67), 8 locked for R7

8. 11(3) cage at R3C7 = {137/146/236} (cannot be {128/245} which clash with R3C34), no 5,8, clean-up: no 2 in R4C9 (step 1)
8a. 6 of {146} must be in R3C78 (R3C78 cannot be {14} which clashes with R3C34), no 4 in R3C78
8b. Killer pair 1,2 in R3C34 and R3C78, locked for R3

9. 9 in N6 locked in R4C7 + R5C789 + R6C9, locked for 35(6) cage, clean-up: no 3 in R7C8 (step 3)
9a. Max R7C9 = 8 -> max R6C78 (step 3a) = 8, no 8
9b. 8 in N6 locked in R4C7 + R5C789 + R6C9, locked for 35(6) cage, clean-up: no 4 in R7C8 (step 3)
9c. Max R7C9 = 7 -> max R6C78 (step 3a) = 7, no 7
[I originally started this as step 4 but it’s more interesting here when it can be used recursively]

10. 12(3) cage at R6C7 = {129/138/147/156/237} (cannot be {246} because 2,4,6 only in R6C78, cannot be {345} which clashes with R4C89)
10a. 5 of {156} must be in R7C8, no 5 in R6C78

11. 5 in N6 locked in R4C7 + R5C789 + R6C9, locked for 35(6) cage, clean-up: no 7 in R7C8 (step 3), clean-up: no 1 in 35(6) cage (prelim i, because 5 locked in cage)
11a. 1 in N6 locked in R6C78, locked for R6, clean-up: no 8 in R5C4, no 9 in R6C1 (step 2)

12. 12(3) cage at R6C7 (step 10) = {129/138/156}, no 4
12a. R5C5 + R6C56 (step 6a) = {128/137/146/236/245}
12b. 1 of {128/137} must be in R5C5 -> no 7,8 in R5C5

13. 35(6) cage at R4C7 = {245789/345689}, CPE no 4 in R4C9, clean-up: no 6 in R4C8 (step 1)
13a. 3 of {345689} must be in R7C9 (R4C7 + R5C789 + R6C9 cannot be {35689} which clashes with R4C89), no 3 in R4C7 + R5C789 + R6C9

14. 21(3) cage at R3C2 = {489/579/678}
14a. 6 of {678} must be in R3C2 (R4C23 cannot be {67} which clashes with R4C89), no 6 in R4C23

15. 45 rule on R1234 3(1+2) innies R3C1 + R4C17 = 1 outie R5C6 + 3
15a. Max R3C1 + R4C17 = 12, min R3C1 = 5 -> max R4C17 = 7, no 7,8,9, no 6 in R4C1
15b. Min R3C1 + R4C17 = 5 + 3 = 8 -> min R5C6 = 5

16. 45 rule on C789 2 innies R78C7 = 1 outie R9C6 + 10
16a. Min R78C7 = 11, no 1
16b. Max R78C7 = 17 -> max R9C6 = 7

17. 45 rule on C1234 5(2+3) innies R23C3 + R234C4 = 29
17a. R3C34 = 6 (step 5) -> R2C3 + R24C4 = 23
17b. Max R2C34 = 17 -> min R4C4 = 6
17c. Max R24C4 = 17 -> min R2C3 = 6
17d. Max R2C3 + R4C4 = 18 -> min R2C4 = 5

18. 1 in N4 locked in 28(6) cage at R3C1
18a. 28(6) cage at R3C1 = {123589/123679/124579/124678/134569/134578}
18b. Killer triple 2,3,4 in 28(6) cage and R6C12, locked for N4

19. 21(3) cage at R3C2 = {579/678}, 7 locked in R4C23, locked for R4 and N4, clean-up: no 3 in R4C89 (step 1), no 3 in R6C12 (step 2)
19a. R4C89 = [46], clean-up: no 8 in R1C9, no 2 in R89C9

20. R4C8 = 4 -> R3C78 = {16} (step 8), locked for R3 and N3, clean-up: no 8 in R3C12 (step 4), no 5 in R3C34 (step 5)
20a. Naked pair {59} in R3C12, locked for R3 and N1, clean-up: no 2 in R12C1
20b. Naked pair {24} in R3C34, locked for R3 and 31(6) cage at R3C3

21. 21(3) cage at R3C2 = {579} (only remaining combination), CPE no 5,9 in R5C2
[That CPE could have been given in step 20a]
21a. 8 in R4 locked in R4C456, locked for N5, clean-up: no 1 in R5C4
21b. R4C456 + R5C6 (step 6b) = {1789/3589}, no 6

22. 1 in C9 locked in R89C9 = {17}, locked for C9 and N9, clean-up: no 5 in R1C8, no 5 in R7C8 (step 3)

23. Hidden killer pair 1,3 in R4C1 and R4C56 for R4 -> R4C1 = {13}
23a. Killer pair 1,3 in R12C1 and R4C1, locked for C1, clean-up: no 9 in R9C2
23b. R4C7 = 2 (hidden single in R4)

24. 35(6) cage at R4C7 (step 13) = {245789} (only remaining combination) -> R7C9 = 4, R7C8 = 8 (step 3), clean-up: no 6 in R7C67 (step 6)
24a. Naked pair {13} in R6C78, locked for R6, clean-up: no 6 in R5C4
24b. Naked pair {59} in R7C67, locked for R7 and 25(5) cage at R5C5

25. R5C5 + R6C56 (step 6a) = {146/236} (cannot be {137} because 1,3 only in R5C5), no 7
25a. 1,3 only in R5C5 -> R5C5 = {13}, 6 locked in R6C56, locked for R6 and N5, clean-up: no 3 in R5C4, no 4 in R6C12 (step 2)
25b. Naked pair {28} in R6C12, locked for R6 and N4, clean-up: no 7 in R5C4
25c. Naked pair {46} in R6C56, locked for R6 and N5, clean-up: no 5 in R56C4
25d. R56C4 = [27], R3C34 = [24]
[In step 25b I missed CPE no 2,8 in R8C2; I don’t think this made much difference.]

26. R6C56 = {46} -> R5C5 = 1 (step 25)
26a. R4C1 = 1 (hidden single in N4), clean-up: no 6 in R12C1
26b. Naked pair {34} in R12C1, locked for C1 and N1, clean-up: no 8 in R9C2

27. Naked pair {59} in R3C1 + R6C3, locked for 28(6) cage at R3C1 -> R5C1 = 6

28. R2C9 = 2 (hidden single in C9)

29. Naked pair {59} in R57C6, locked for C6

30. 11(3) cage at R6C2 = [236/263/821], no 1,7 in R7C2, no 7 in R7C3

31. R789C4 = {138/156}, no 9, 1 locked for C4 and N8

32. 15(4) cage at R8C8 = {2346) (only remaining combination) -> R9C6 = 4, R6C56 = [46], 3,6 locked for N9, clean-up: no 8 in R9C1
32a. Naked pair {59} in R78C7, locked for C7
32a. Naked triple {136} in R369C7, locked for C7
32b. Hidden killer pair 5,9 in R1C89 and R2C8 for N3 -> R2C8 = {59}

33. 19(4) cage at R1C2 = {1378/1567} (cannot be {1369} because 3,9 only in R1C4), no 9
33a. 3,5 only in R1C4 -> R1C4 = {35}
33b. Killer pair 3,5 in R1C4 and R1C89, locked for R1 -> R12C1 = [43]
33c. Killer pair 3,5 in R1C4 and R789C4, locked for C4
33d. R2C7 = 4 (hidden single in C7)

34. 45 rule on N2 1 outie R2C3 = 1 remaining innie R1C4 + 3 -> R2C3 = {68}
34a. 6 in N2 locked in R1C5 + R2C45, locked for 28(5) cage at R1C5 -> R2C3 = 8, R1C4 = 5, clean-up: no 7 in R1C8, no 6 in R789C4 (step 31)

35. Naked pair {39} in R1C89, locked for N3 -> R2C8 = 5, R3C9 = 8, R1C7 = 7, R5C7 = 8
35a. Naked pair {59} in R56C9, locked for C9 and N6 -> R1C89 = [93], R5C8 = 7
35b. Naked pair {16} in R1C23, locked for R1 and N1 -> R1C56 = [28], R2C2 = 7, R2C6 = 1, R4C6 = 3, R3C56 = [37], R8C6 = 2, clean-up: no 5 in R9C1

36. Naked triple {138} in R789C4, locked for C4 and N8 -> R4C4 = 9, R2C45 = [69], R4C23 = [57], R3C12 = [59], R4C5 = 8, R5C6 = 5, R56C9 = [95], R6C3 = 9, R7C67 = [95], R8C7 = 9, R9C2 = 3, R9C1 = 9, R5C23 = [43], R9C78 = [62], R8C8 = 3, R3C78 = [16], R6C78 = [31]

37. 11(3) cage at R6C2 (step 30) = [821]

and the rest is naked singles

Thanks for all the helpful comments to my walkthrough. As I said, I'm a little rusty, so it wasn't optimal and I omitted some steps. I'll have a look at it, but not before Tuesday, sorry.

Whew! Finally solved this V2. A really easy-to-follow solution too (no big combo crunching) - just super hard to find. I'll rate it 2.0 because it feels too hard to be the "official" weekly assassin. I think most would prefer to do it 'tag' style. Sorry if I just scared everyone off!!

Of course, like in the V1, I may have missed something important, like some cage cleanup in the V1. Can't wait to find out how SS does this one since it gives it a score of 1.25. I'll have a look before a follow-up post about a new move I found doing this V2. In about a week.

Assassin 144 v2



Cheers
Ed

I have to agree that the important move was hard to find (it took me some time) since you usually don't look for these things but the move itself wasn't particularly difficult so I agree with SudokuSolver's rating.

A144 V2 Walkthrough:

1. N5
a) 3(2) = {12} locked for C4+N5
b) Innies N1247 = 4(2) = {13} -> R3C4 = 3, R3C3 = 1
c) 31(6) = 1369{48/57} -> 6,9 locked for N5
d) Innies N5 = 15(3) = 3{48/57} -> 3 locked for 25(5)
e) Outies N5 = 10(2) <> 5,7

2. R123 !
a) Outies N47 = 10(2) = {28/46}
b) 26(4): R1C4 <> 5 because R1C23+R2C2 = 8{49/67} blocked by Killer pairs (48,68) of Outies N47
c) Innies C123 = 23(4) = {2579/3479/3569/3578} since 8{249/267/456} blocked by Killer pairs (24,68) of Outies N47
d) ! Innies C123 = 23(4): R2C3 <> 4,6 because R1C23+R2C2 @ 26(4) cannot be 39{5/7}
e) Innies+Outies C123: 3 = R1C4 - R2C3 -> R2C3 = (35), R1C4 = (68)
f) 27(5) = {14589/23589/23679/24579/34569/34578} because R2C3 = (35) and 168{39/57} blocked by R1C4 = (68)
g) 12(3) = 1{29/47/56} <> 8 since {246} blocked by Killer pair (24) of 27(5) -> 1 locked for C6+N2

3. C456
a) Innies C4 = 18(3) = 6{48/57} since R1C4 = (68) -> 6 locked for C4
b) 21(3) = 9{48/57} -> 9 locked for N8
c) Outies N5 = 10(2) = {28/46}
d) Innies N5 = 15(3) = {357} locked for N6 since {348} blocked by Killer pair (48) of Outies N5
e) Innies C4 = 18(3) = {468} locked for C4 because R14C4 = (468)
f) 21(3) = {579} locked for N8

4. R1234
a) Innies+Outies R1234: 2 = R5C6 - (R3C1+R4C17) -> R5C6 = (89); R3C1+R4C17 <> 5,6,7,8,9 since R3C1 >= 2
b) 31(6) = {134689} -> 4,6 locked for R4
c) Outies N3 = 13(2) = {58} locked for R4+N6
d) Hidden Single: R5C6 = 8 @ N5
e) 31(6) = {134689} -> 9 locked for R4
f) Outies N47 = 10(2) = [28/46]
g) 7 locked in 17(3) @ R4 = {278} -> R3C2 = 8; 2,7 locked for R4+N4
h) Outie N47 = R3C1 = 2

5. C789
a) 9 locked in R23C9 @ C9 for N3
b) 18(3) = 6{48/57} -> 6 locked for R3+N3
c) 32(6) = 1789{25/34} -> 1,7 locked for N3
d) 8(2) = {35} locked for R1+N3
e) 32(6) = {125789} -> R4C9 = 5
f) R4C8 = 8, R1C9 = 3, R1C8 = 5
g) 1 locked in 23(6) @ N6 for 23(6)
h) 19(3) = 9{37/46}
i) Outies N36 = 10(2) = [37/46/64]

6. R789
a) Killer pair (67) locked in Outies N36 + 8(2) for N9
b) 1,8 locked in 23(5) @ N8 for C5+23(5) -> 23(5) = 138{29/56} -> R8C7 = (59)
c) Outies N5 = 10(2) = [28/64]
d) Hidden Single: R9C6 = 4 @ N8
e) 18(4) = {2349} because 5,8 only possible @ R9C7; {239} locked for N9
f) Outies N36 = 10(2) = {46} locked for R7+N9
g) R7C7 = 8
h) 20(3) = 9{47/56}

7. C1234
a) Hidden Single: R2C9 = 8 @ C9, R1C4 = 8 @ N2
b) Outie N2 = R2C3 = 5
c) Outies N7 = 11(2) = {56} locked for R6+N4
d) 20(3) = {569} -> R7C3 = 9, R7C2 = 5, R6C2 = 6
e) 27(5) = {24579} -> R2C4 = 4; {279} locked for C5+N2
f) 26(4) = {3689} -> R1C3 = 6, R1C2 = 9, R2C2 = 3
g) R2C1 = 7, R1C1 = 4
h) 9(2) = {18} -> R9C2 = 1, R9C1 = 8

8. Rest is singles.

Rating: (Hard?) 1.25. I used combo analysis.

Here's how I solved v2.

The usual preliminary innies and outies include R4C89 = 13.

There are 3 possibilities:

1. R4C89 = {67}. By tracking along R4 this quickly leads to a contradiction with the 17(3) cage.
2. R4C89 = {49}. This leads to a contradiction but by a slightly longer path.
3. R4C89 = {58}. Actually [85].

From here the puzzle drops out. In fact, if you start SS from this point the score
drops from 1.25 to 0.76 - just a tad higher than a typical Times deadly killer.

I am not sure I have seen the important move since I had to use technical moves. Here is my wt, different from Afmob's who seems to have found a more direct path.

Edit : have changed slightly my wt : it might be easier to read and avoid some previous horrible combinations !
WALKTHROUGH A144 V2

1)Innies for n1247 : r3c34 totals 4 → r3c34={13}. Split cage 31(6) → hidden cage 27(4) at r3c4 and r4c456.

2){12} locked for c4 and n5 in cage 3(2) → r3c34=[13]

3)Outies for n47 : r3c12 totals 10 → combinations {28/46}

4)Outies n3 → r4c89 totals 13 : {49/58/67}

5)Innies for n3689 : r7c67 totals 10 → split cage 25(5) : hidden cage 15(3) at r5c5 and r6c56.

6)Hidden single 3 for hidden cage 15(3) at n5 : combinations {348/357} → hidden cage 27(4) at n5 admits combinations {4689/5679}

7)IO for r4 : r3c2+r5c6 =12+r4c1+r4c7 → r3c2+r5c6 >= 15 → r3c2={68}. We deduce from step 3) that r3c12=[28/46]

8)Combinations using steps 4) and 6) : r4c45689={567}{49} / {269}{58} / {469}{58} / {489}{67}
→ r4c1237 ={1238/1234/1237/1235}
(If r4c89= {49}, hcage 27(4) at n5 cannot be {4689} and if r4c89={67}, hcage 27(4) at n5 cannot be {5679}).

9)Since r3c2={68}, there is no valid combinations for cage 17(3) at n14 if r4c123={1234/1235} → r4c45689={567}{49} / {469}{58}. We deduce that cage 17(3) at n14 admits the following combinations : 6{38} or 8{27} and there is no {67} for r4c89.

10)Outies for n7 : r6c12 totals 12 → hidden cage 11(2) at r6c12

11)- If cage 17(3) at n14=6{38}, r3c1=4 (step 3) ) and 4 is locked for n4 at r6c2 → r6c12=[74]
-If cage 17(3) at n14=8{27} and r6c12={38/56} (no other combinations)
→ No {29} for r6c12

12)cage 23(6) at n69 must uses digit 4 → r4c9 <> 4

13) There is no 4 at r4c8 ! By contradiction, if r4c8=4, r7c9=4 since cage 23(6) must use digit 4, so r7c8=6, r6c78 totals 13 and cannot contain 4 or 6 → r6c78={58} and r6c12={47} (no 2,9 from
step 11) , and these two previous combinations block hcage 15(2) at n5 (step 6 : {348} / {357})
→ r4c89={58}

14)From step 9, we deduce that cage 17(3) at n14 = 8{27}, r3c1=2, r4c234={469}, r5c6=8, and hidden cage 15(3) at n5 is composed by {357}

15)No 8 at r3c78 since r4c8 ={58} (no valid combination) → digit 8 is locked for n3 in cage 32(6) → r4c9<>8.
We deduce from step 13) that r4c89=[85].

16)R3c78={46} (last combination for cage 18(3) ) and 5 is locked for n3 at r1c8 → r1c9=3

17)Digit 5 is locked for r3 at r3c56 → 5 is locked for c4 in cage 21(3) : r789c4 = {579}, 5 7 and 9 locked for c4 and n8. R4c4={46}, {468} locked at r124c4, 8 locked for n2

18)IO for n1 : r1c4 = r2c3+3 → from step 17, r1c4={68} r2c3= {35} (no 1 at r2c3)

19) r2c1<>6 since r1c1 cannot be 5 → digit 6 is locked for n1 at r1c123+r2c2 → r1c4 <>6, so r1c4=8 and r2c3=5 (step 18) ).

20)Cage 11(2) at c1={47}, cage 26(4) at n1 = {369} with r2c2=3

21) Combinations for hcage 11(2) at n4 : {38/56} : {38} blocked by r23c3=[38] → r6c12={56}

22)HS for n5: r5c5=5, r6c56={37}, HS for n4 : r6c3=8

23)Digit 8 at r4c8 sees all cells of cage 19(3) at n69 → no 1 2 → Hidden pair {12} for r6 locked at r6c49 → r6c78={49}, r7c8=6, r7c9=4
(HS for c9)

24)HS for nr3 : r3c6=5 → r12c6=[16]

25)8 locked for c1 at r789c1 → r6c2<>5 (no combination for cage 20(3) ) → r6c12=[56], r7c23=[59]

26)NS : r7c4=7, r7c67=[28] (last combination for hidden cage 10(2))

27)HS for r6 : r4c6=9, r6c6=7

28)Last combination for cage 8(2) at c9 : {17}

29)HS for c4 : r2c4=4, r4c4=6

30)NS : r89c6 = {34}.

31)HS : r3c78=[64], r7c78=[49]

32)IO for n9 : r8c7=1+r9c6 : r8c7<>4 → (step 30) ) r8c7=5, r89c6=[34]

33)The rest is naked singles