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Prelims

a) R1C12 = {14/23}
b) R12C3 = {29/38/47/56}, no 1
c) R12C4 = {19/28/37/46}, no 5
d) R2C12 = {69/78}
e) R34C1 = {18/27/36/45}, no 9
f) R34C2 = {29/38/47/56}, no 1
g) R3C34 = {29/38/47/56}, no 1
h) R67C8 = {69/78}
i) R67C9 = {29/38/47/56}, no 1
j) R7C67 = {17/26/35}, no 4,8,9
k) R89C6 = {59/68}
l) R89C7 = {18/27/36/45}, no 9
m) R8C89 = {14/23}
n) R9C89 = {69/78}
o) 7(3) cage at R3C9 = {124}
p) 13(4) cage at R8C3 = {1237/1246/1345}, no 8,9
q) 32(5) cage at R1C9 = {26789/35789/45689}, no 1

Steps resulting from Prelims
1a. 32(5) cage at R1C9 = {26789/35789/45689}, 8,9 locked for N3
1b. Naked triple {124} in 7(3) cage at R3C9, CPE no 1,2,4 in R56C9, clean-up: no 7,9 in R7C9

2. 45 rule on N3 1 outie R1C6 = 1 innie R3C9 + 3, R3C9 = {124} -> R1C6 = {457}

3. 45 rule on N7 1 innie R7C1 = 1 outie R9C4 + 2, no 1,2 in R7C1

4. 45 rule on N9 2 innies R7C89 = 1 outie R7C6 + 8 -> no 8 in R7C89 (IOU), clean-up: no 7 in R6C8, no 3 in R6C9
4a. 45 rule on N9 3 innies R7C789 = 16 = {169/259/457} (cannot be {349} which clashes with R8C89, cannot be {367} which clashes with R9C89), no 3, clean-up: no 8 in R6C9, no 5 in R7C6
4b. 7 of {457} must be in R7C8 -> no 7 in R7C7, clean-up: no 1 in R7C6
4c. 7,9 only in R7C8 -> R7C8 = {79}, clean-up: no 9 in R6C8
4d. 1 of {169} must be in R7C7 -> no 6 in R7C7, clean-up: no 2 in R7C6
4e. {259} can only be [592] (cannot be [295] because R6C89 would be [66]), no 2 in R7C7, no 5 in R7C9, clean-up: no 6 in R6C9, no 6 in R7C6
4f. Killer pair 7,9 in R6C8 and R9C89, locked for N9, clean-up: no 2 in R89C7
4g. 5 in N9 only in R789C7, locked for C7

5. 45 rule on N1 2 innies R3C12 = 1 outie R3C4 + 3, no 3 in R3C12 (IOU), clean-up: no 6 in R4C1, no 8 in R4C2

6. Consider combinations for R8C89
R8C89 = {14} => naked triple {124} in R348C9, locked for C9
or R8C89 = {23}, locked for N9
-> no 2 in R7C9, clean-up: no 9 in R6C9
6a. 2 in N9 only in R8C89 = {23}, locked for R8 and N9, clean-up: no 6 in R89C7
6b. 1 in N9 only in R789C7, locked for C7

7. Caged X-Wing for 2 in 7(3) cage at R3C9 and R8C89, no other 2 in C89

8. R7C789 (step 4a) = {169/457} = [196/574], R7C56 = [35/71] -> variable combined cage R7C6789 = [3574/7196], 7 locked for R7, clean-up: no 5 in R9C4 (step 3)

9. 16(4) cage at R1C6 = {1267/1357/1456/2347/2356}
9a. 1 of {1357/1456} must be in R1C8, 5 of {2356} must be in R1C6) -> no 5 in R1C8
9b. 45 rule on N3 4 innies R1C78 + R2C7 + R3C9 = 13 = {1237/1246}, 2 locked for N3

10. 16(4) cage at R1C6 = {1267/1357/1456/2347} (cannot be {2356} because R1C78 + R2C7 (step 9b) cannot contain both of 3,6)
10a. 1 of {1267/1456} must be in R1C8 -> no 6 in R1C8
10b. 5,7 of {1267/1357/1456} must be in R1C6, 4 of {2347} must be in R2C7 (R1C678 cannot contain both of 2,4 which would clash with R1C12) -> no 4 in R1C6, clean-up: no 1 in R3C9 (step 2)

11. R1C8 = 1 (hidden single in N3), clean-up: no 4 in R1C12, no 9 in R2C4
11a. Naked pair {23} in R1C12, locked for R1 and N1, clean-up: no 8,9 in R12C3, no 7,8 in R2C4, no 8,9 in R3C4, no 7 in R4C1, no 9 in R4C2
11b. R4C9 = 1 (hidden single in N6), clean-up: no 8 in R3C1
11c. Naked pair {24} in R3C9 + R4C8, CPE no 4 in R23C8
11d. Killer pair 6,7 in R12C3 and R2C12, locked for N1, clean-up: no 4,5 in R3C4, no 2,3 in R4C1, no 4,5 in R4C2
11e. 1 in N4 only in R56C123, CPE no 1 in R6C4

12. 16(4) cage at R1C6 (step 10) contains 1 = {1267/1357/1456}
12a. 2,3 of {1267/1357} must be in R2C7 -> no 7 in R2C7

13. R3C1 = 1 (hidden single in N1), R4C1 = 8, clean-up: no 7 in R2C2, no 6 in R9C4 (step 3)

14. 18(3) cage at R4C3 cannot be {189} (because 1,8 only in R5C4) -> no 1 in R5C4

15. 14(3) cage at R6C1 = {149/167/239/257/347/356}
15a. 1 of {149} must be in R6C2, 9 of {239} must be in R67C1 (R67C1 cannot be {23} which clashes with R1C1), no 9 in R6C2

16. 45 rule on N8 4 innies R789C4 + R7C6 = 16 = {1267/1348/1357/2347} (cannot be {1249/1258/1456} because R7C6 only contains 3,7, cannot be {2356} which clashes with R89C6), no 9

17. 36(7) cage at R2C6 can only contain 8 if it also contains 1, 1 only in R2C6 -> no 8 in R2C6
17a. 45 rule on N2 4 innies R3C4 + R123C6 = 21 = {1569/2379/2478/3459} (cannot be {1389/2469/3468} because R1C6 only contains 5,7, cannot be {1479} because 1,4,9 only in R23C6, cannot be {1578/2568} which clash with R89C6, cannot be {3567} because 3{567}/7{356} clash with R89C6 and 6{357} clashes with R7C6)
17b. R1C6 = {57} -> no 5,7 in R3C4 + R23C6, clean-up: no 4 in R3C3
17c. 6 of {1569} must be in R3C4 -> no 6 in R23C6
17d. 3 of {2379} must be in R3C4 (R123C6 cannot be {379} which clashes with R7C6), 3 of {3459} must be in R3C4 -> no 3 in R23C6

18. Killer pair 8,9 in R3C4 + R123C6 and R89C6, locked for C6
18a. 14(3) cage at R1C5 = {158/167/248/347/356} (cannot be {149/239} which clash with R3C4 + R123C6), no 9

19. R789C4 + R7C6 (step 16) = {1348/1357/2347} (cannot be {1267} which clashes with R123C4), no 6, 3 locked for N8
[This would have worked in step 16, but I didn’t spot it then.]

20. 33(7) cage at R5C1 must contain 6 in R5C123 + R6C34, CPE no 6 in R6C12

21. 45 rule on N1 2 remaining outies R3C4 + R4C2 = 9 = [27/36/63], no 2 in R4C2, clean-up: no 9 in R3C3

[Wish I’d spotted this next step earlier …]
22. 45 rule on N1 1 remaining innie R3C2 = 1 outie R3C4 + 2 -> R3C24 = [53/86] (cannot be [42] which clashes with R3C9), no 4 in R3C2, no 2 in R3C4, clean-up: no 9 in R3C3, no 7 in R4C2
22a. Naked pair {58} in R3C23, locked for R3 and N1, clean-up: no 6 in R12C3, no 7 in R2C1
22b. Naked pair {47} in R12C3, locked for C3
22c. Naked pair {69} in R2C12, locked for R2, clean-up: no 4 in R1C4
22d. R3C4 + R4C2 (step 21) = {36}, CPE no 3,6 in R4C4

23. R3C4 + R123C6 (step 17a) = {1569/2379/3459} -> R3C6 = 9, clean-up: no 1 in R2C4, no 5 in R89C6

24. R6C7 = 9 (hidden single in N6), R56C6 = 3 = {12}, locked for C6 and N5 -> R2C6 = 4, R12C3 = [47], clean-up: no 6 in R1C4
24a. Naked pair {68} in R89C6, locked for C6 and N8

25. R4C8 = 4 (hidden single in N6), R3C9 = 2, R8C89 = [23], R2C7 = 3, R2C4 = 2, R1C4 = 8, R1C6 = 5 (step 2), R1C7 = 7 (cage total), R12C5 = [61], R3C45 = [37], R3C3 = 8, R3C2 = 5, R4C2 = 6, clean-up: no 4,5 in R7C1 (step 3)

26. 33(7) cage at R5C1 must contain 6 -> R6C4 = 6, R6C8 = 8, R7C8 = 7, R7C6 = 3, R7C7 = 5, R3C8 = 6, R9C8 = 9, R9C9 = 6, R7C9 = 4, R2C12 = [69], R7C1 = 9, R9C4 = 7 (step 3)

27. R7C5 = 2, R89C5 = 13 = [94]

28. R4C67 = [72], R5C789 = [635], R78C4 = [15], R45C4 = [94], R78C3 = [61]

29. Naked pair {23} in R19C2, locked for C2 -> R5C2 = 7

and the rest is naked singles.

I’ll rate my walkthrough for Pinata #9 at 1.5. I used a very short forcing chain, which I’d rate at Easy 1.5, but went a bit higher because of the “Sudoku Solver type” analysis in steps 16, 17a and 19.

Please let me know if anything is wrong or could be clearer.

1. 7(2)r3c9 = {124}
1a. r56c9 sees all of the 7(2) -> no 1,2,4 in r56c9
1b. 11(2)r6c9: no 1, no 7,9 in r7c9

2. "45" on n9: 1 outie r7c6 + 8 = 2 innies r7c89
2a. -> no 8 in either of r7c89 since it would force r7c6 = other one of r7c89 (IOU)
2b. 15(2)r6c8: no 1,2,3,4,5; no 7 in r6c8
2c. no 3 in r6c9

3. 8(2)r7c6: no 4,8,9
3a. "45" on n9: 3 innies r7c789 = 16
3b. but {349} clashes with 5(2)n9 = {14/23}(no 5..9) = [3/4..]
3c. and {367} clashes with 15(2)n9 = {69/78}(no 1..5) = [6/7..]
3d. -> h16(3)r7c789 = {169/259/457}(no 3)
3e. no 5 in r7c6
3f. no 8 in r6c9

4. h16(3)r7c789 = {169/259/457}
4a. but {259} as [295] is blocked by 6 in both r6c89 (Blocking cages)
4b. ->no 2 in r7c7
4c. no 6 in r7c6

5. h16(3)r7c789 = {169/259/457}
5a. =[196/592/574] only permutations possible
5b. r7c7 = (15), r7c8 = (79), r7c9 = (246)
5c. no 1,2 in r7c6
5d. no 9 in r6c8
5e. no 6 in r6c9

6. r3478c9 from {12346} ie, five candidates for four cells [Almost Locked Set] (ALS) -> must have at least one 3 or 6 which are both in n9
6a. -> {36} blocked from 9(2)n9
6b. -> 3 in n9 only in 5(2) = {23}, both locked for r8 and 2 for n9
6c. 9(2) = {18/45}(no 6,7,9)
6d. no 9 in r6c9

7. 1 & 5 in n9 only in c7: both locked for c7

8. 32(5)n3 = {26789/35789/45689}(no 1)
8a. must have 8 & 9: both locked for n3
8b. "45" on n3: 1 innie r3c9+3 = 1 outie r1c6 (IOD=+3)
8c. r1c6 = (457)

9. 5(2)n1 = {14/23}(no 5..9) = [2/4,3/4..]
9a. 16(4)r1c6
9b. but {2347} as [4]{237} clashes with 5(2)n1
9c. and {2347} as [7]{234} clashes with IOD n3 = +3 (step 8b.)
9d. but {2356} is [5]{236} which clashes with IOD n3 = +3 (step 8b.)
9e. 16(4) = {1267/1357/1456}
9f. must have 1 -> r1c8 = 1
9g. no 4 in r1c6 (IOD n3 = +3)
9h. 5(2)n1 = {23} only: both locked for r1 and n1

10. Hidden single 1 in n6 -> r4c9 = 1

11. 15(2)n1 = {69/78}:no 1,4,5 = [6/7..]
11a. 11(2)r1c3 = {47/56}(no 1,8,9) = [6/7..]
11b. Killer pair 6,7 in those two cages: both locked for n1
11c. 11(2) cages at r3c23 (no 1): r4c2+r3c4 both = (2367)

12. Hidden single 1 in n1 -> r3c1 = 1
12a. r4c1 = 8
12b. no 7 in r2c2

This is the key step which I couldn't find first time through, but after finding a similar move in the reflected part of the puzzle, found it is even more powerful here. The key to getting it to work as a "anti-clone" is to have a "45" which has 2 outies and 2 innies rather than 3+1 outies & innies. Anyway...
13. "45" on n2369: 2 outies r3c3+r4c6 - 1 = 2 innies r67c7
13a. but 1 outie r3c3 - 1 cannot equal 1 innie r7c7 since no 2 or 6 in r3c3
13b. -> the other outie r4c6 cannot equal the other innie r6c7 (Anti-clone) (no eliminations yet)

14. r4c6 sees all of n6 apart from r6c789 -> must be repeated (Cloned) there
14a. but r4c6 <> r6c7 (step 13b) -> r4c6 = one of r6c89 (from 5,6,7,8)
14b. -> r4c6 from (567) only

15. 14(2)n8 = {59/68}(no 1,2,3,4,7) = [5/6..]
15a. r147c6 from (3567) ie, three cells have four candidates (ALS)
15b. but cannot have both 5 & 6 because of 14(2)
15c. -> must have 3 & 7 -> r7c6 = 3, 7 locked for c6
15d. r14c6 must have one of 5 or 6: -> Killer pair 5,6 with 14(2)n8: both locked for c6

16. r7c7 = 5 -> r7c89 = [74] (step 5a)
16a. r6c89 = [87]
16b. -> r4c6 = 7 (step 14a)
16c. r1c6 = 5, r3c9 = 2, r4c8 = 4
16d. 14(2)n8 = {68} only: both locked for n8 and 8 for c6

17. 18(3)r4c3
17a. but {189} not possible since 1&8 only in r5c4
17b. and {468} not possible since 4&8 only in r5c4
17c. = {369/459}(no 1,2,8)

18. Hidden single 8 in n5 -> r5c5 = 8
18a. 8 in n2 only in 10(2) = [82] only

19. 15(2)n9 = {69} only: both locked for r9
19a. r89c6 = [68]

20. naked pair {69} at r19c9: both locked for c9
20a. r8c9 = 3
20b. r5c9 = 5

on from there.