Thanks Afmob. I enjoyed that this one. I hope we'll see some walkthroughs from solvers who don't usually post them.
I'll rate A145 at 1.0. I hope that step 9c, which made things a bit quicker but wasn't a key breakthrough, counts within this rating.
Edit. Ed's message below suggests that my walkthrough should be rated 1.25; he's probably right. However Ed also shows an alternative step at this stage so a rating of 1.0 is valid for A145.Here is my walkthrough.
I've simplified steps 19 and 25.Prelims
a) R4C45 = {39/48/57}, no 1,2,6
b) R5C12 = {29/38/47/56}, no 1
c) R6C45 = {29/38/47/56}, no 1
d) R5C456 = {127/136/145/235}, no 8,9
e) 10(3) cage at R6C9 = {127/136/145/235}, no 8,9
f) 11(3) cage in N9 = {128/137/146/236/245}, no 9
g) 20(3) cage in N9 = {389/479/569/578}, no 1,2
h) 28(4) cage at R1C5 = {4789/5689}, no 1,2,3
i) 27(4) cage at R7C3 = {3789/4689/5679}, no 1,2
1. 45 rule on N1 2 innies R3C23 = 9 = {18/27/36/45}, no 9
2. 45 rule on N4 2 outies R37C2 = 9 = {18/27/36/45}, no 9
3. 45 rule on N5 2 innies R46C6 = 12 = {39/48/57}, no 1,2,6
3a. 1 in N5 locked in R5C456, locked for R5
4. 45 rule on N6 2 innies R46C9 = 8 = {17/26/35}, no 4,8,9
5. 45 rule on N7 2 innies R7C23 = 11 = [29]/{38/47/56}, no 1, clean-up: no 8 in R3C2 (step 2), no 1 in R3C3 (step 1)
6. 45 rule on N3 1 innie R1C7 = 1 outie R4C9, no 4,8,9 in R1C7, no 1,2,3 in R4C9, no 5,6,7 in R6C9 (step 4)
6a. 8,9 in 28(4) cage locked in R1C56 + R2C6, locked for N2
7. 45 rule on C789 = R19C7 = 12 = {57}, locked for C7, clean-up: no 6 in R4C9 (step 6), no 2 in R6C9 (step 4)
7a. 28(4) cage at R1C5 = {4789/5689}
7b. R1C7 = {57}, no 5,7 in R1C56 + R2C6
8. R4C45 = {39/48} (cannot be {57} which clashes with R4C9), no 5,7
8a. R6C45 = {29/47/56} (cannot be {38} which clashes with R4C45), no 3,8
9. 45 rule on C1234 3 innies R456C4 = 10 = {136/145/235} (cannot be {127} because no 1,2,7 in R4C4), no 7,8,9, clean-up: no 3,4 in R4C5, no 2,4 in R6C5
9a. R4C4 = {34} -> no 3,4 in R56C4, clean-up: no 7 in R6C5
9b. 1 of {136} must be in R5C4, no 6 in R5C4
9c. 2 of {235} must be in R5C4 (R456C4 cannot be [352] because R46C5 would both be 9), no 2 in R6C4, clean-up: no 9 in R6C5
10. Naked pair {56} in R6C56, locked for R6 and N5, clean-up: no 7 in R46C6 (step 3)
10a. R5C456 = {127} (hidden triple in N5), locked for R5, clean-up: no 4,9 in R5C12
11. 28(4) cage at R1C5 = {4789/5689}
11a. R1C5 = {89} (R12C6 cannot be {89} which clashes with R46C6)
11b. Naked pair {89} in R14C5, locked for C5
12. 45 rule on C89 2 innies R37C8 = 8 = {17/26/35}, no 4,8,9
13. 45 rule on N9 3 innies R7C9 + R8C8 + R9C7 = 14 = {167/257/356} (cannot be {347} because 10(3) cage at R6C9 cannot contain both of 3,4), no 4
14. 9 in N9 locked in 20(3) cage = {389/479} (cannot be {569} which clashes with R7C9 + R8C8 + R9C7), no 5,6
14a. 11(3) cage in N9 = {128/146/245} (cannot be {137/236} which clash with R7C9 + R8C8 + R9C7), no 3,7
15. 17(3) cage at R2C8 = {179/278/359/458/467} (cannot be {269/368} because R4C9 only contains 5,7)
15a. R4C9 = {57} -> no 5,7 in R2C8 + R3C9
16. 45 rule on R6789 3 innies R6C378 = 15 = {249/348}, no 1,7, 4 locked for R6, clean-up: no 8 in R4C6 (step 3)
16a. 7 in R6 locked in R6C12, locked for N4 and 17(3) cage at R6C1, clean-up: no 2 in R3C2 (step 2), no 7 in R3C3 (step 1), no 4 in R7C3 (step 5)
16b. 17(3) cage at R6C1 = {278} (only remaining combination, cannot be {179} because 1,7,9 only in R6C12, cannot be {467} because 4,6 only in R7C2) -> R6C12 = {278}, R7C2 = {28}, CPE no 8 in R45C2, clean-up: R3C2 = {17} (step 2), R3C3 = {28} (step 1), no 3 in R5C1, R7C3 = {39} (step 5)
17. R6C9 = 1 (hidden single in R6), R4C9 = 7 (step 4), R1C7 = 7 (step 6), R9C7 = 5
17a. 10(3) cage at R6C9 = {127/136}
17b. 7 of {127} must be in R8C8 -> no 2 in R8C8
18. 28(4) cage at R1C5 = {4789}, no 6, 4 locked in R12C6, locked for C6 and N2, clean-up: no 8 in R6C6 (step 3)
18a. Naked pair {39} in R46C6, locked for C6 and N5 -> R4C45 = [48], R1C5 = 9
19. 45 rule on R1234 3 innies R4C378 = 12 = {129/156} -> R4C3 = 1, R4C78 = [29/65/92], no 6 in R4C8
20. 4 in N4 locked in R56C3
20a. R4C3 = 1 -> R56C3 = {49}, locked for C3 and N4 -> R7C3 = 3, R7C2 = 8 (step 4), R3C2 = 1 (step 2), R3C3 = 8 (step 1)
21. Naked pair {27} in R6C12, locked for R6 and N4
21a. R5C1 = 8 (hidden single in N4), R5C2 = 3
21b. Naked pair {56} in R4C12, locked for R4
21c. Naked pair {29} in R4C78, locked for R4 and N6 -> R4C6 = 3, R6C6 = 9, R56C3 = [94]
22. R7C3 = 3 -> R789C4 = 24 = {789}, locked for C4 and N8
23. 17(4) cage at R8C5 = {2456} (only remaining combination) -> R9C5 = 4, R89C6 = {26}, locked for C6 and N8
23a. Naked pair {15} in R7C56, locked for R7 and N8 -> R8C5 = 3
24. Naked pair {26} in R7C89, locked for R7 and N9 -> R7C7 = 4, R5C7 = 6, R8C8 = 7
24a. R5C7 = 6 -> R46C7 = 10 = [28], R46C8 = [93], R8C7 = 1, R7C8 = 6 (step 14a), R7C9 = 2, R9C8 = 8, R89C9 = [93], R8C4 = 8
24b. R23C7 = {39} -> R3C8 = 2 (cage sum)
25. 8 in N3 locked in 14(3) cage = {158} (only remaining combination) -> R1C8 = 1, R2C8 = 4, R3C9 = 6, R5C89 = [54], R12C6 = [48], R12C9 = [85]
26. 19(4) cage at R1C4 = {2368} (only remaining combination) -> R3C4 = 3, R12C4 = {26}, locked for C4 and N2 -> R5C4 = 1, R5C56 = [27], R6C45 = [56], R3C56 = [75], R2C5 = 1, R7C56 = [51], R23C7 = [39], R3C1 = 4
27. 9 in N1 locked in 15(3) cage = {249} (only remaining combination) -> R2C12 = {29}, locked for R2 and N1 -> R12C4 = [26], R2C3 = 7
28. R1C1 = 3, R9C1 = 1 (hidden singles in C1), R8C2 = 4 (hidden single in C2)
28a. R8C2 = 4 -> R78C1 = 13 = [76]
and the rest is naked singles
Afmob wrote:
I haven't planned a V2 (yet?) but there are lots of other V2s which should have more walkthroughs so that should keep you busy.
There certainly are. Ed's A144 V2 and Frank's A142 V2 are two that I haven't yet finished but hope to do so.