SudokuSolver Forum

Hi folks,

Welcome to my first puzzle(s) on the SS forum!

Tried to create a nice killer with a whirling cage pattern, and always ended up with one row and column left over. So decided to simply cut them out and go for an 8 x 8 killer instead!

Cyclone V1 (Est. rating: 1.25)



2x4::k:4096:4096:5378:5378:5378:5378:2054:2054:4096:3337:5378:3595:3595:2573:2573:2054:5392:3337:2578:3595:1300:1300:6422:6422:5392:4121:2578:3867:3867:4637:4637:6422:5392:4121:4121:3867:3867:2853:4637:6422:5392:5392:1834:1834:3628:2853:3118:6422:2864:1329:1329:3628:3628:6453:3118:2871:2864:2864:6453:6453:6453:6453:2871:2871:

Solution:

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


Cyclone V2 (Est. rating: 1.75)



2x4::k:3328:3328:5890:5890:5890:5890:4102:4102:3328:1801:5890:3339:3339:1805:1805:4102:4880:1801:2834:3339:2324:2324:5398:5398:4880:4377:2834:4379:4379:3613:3613:5398:4880:4377:4377:4379:4379:2341:3613:5398:4880:4880:3114:3114:3628:2341:2606:5398:3888:2097:2097:3628:3628:6709:2606:1847:3888:3888:6709:6709:6709:6709:1847:1847:

Solution:

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

Have fun with those "36" tests!

P.S. Only JSudoku seems to be able to handle non-standard grid sizes, so no SScore this time.

BTW, here is a killer combination table for 8x8, which you may find useful:

_________________
Cheers,
Mike

Thanks Mike for providing a nice Killer which had an interesting move (step 2f -> Grouped X-Wing). But I don't know if I tackle V2 because I am used to solve Killers with SumoCue and it's quite tedious to make eliminations with other programms, so I had quite a fight to solve it using JSudoku.

By the way, did you post them because there was only a bit of activity this week on your uA? Maybe your Killer was too hard or everybody got the same solving path.

Note: I used B for Blocks since there are no Nonets.

Cyclone V1 Walkthrough:

1. R678
a) Innies B7 = 20(3) = {578} locked for B7
b) Outies R78 = 6(2) = [15/24]
c) 12(2): R7C7 <> 4,5
d) 14(3): R7C5 <> 1,2,3 because R6C5 = (12)
e) Killer pair (78) locked in 14(3) + R7C7 for R7
f) 7(2) <> {25} because it's a Killer pair of Outies R78
g) Killer pair (14) locked in 7(2) + Outies R78 for R6
h) Outies R8 = 11(3) <> 5 because {245} blocked by Killer pair (24) of 5(2)
i) 5 locked in 14(3) @ R7 = 5{18/27}

2. C5678 !
a) Outies C78 = 12(2) = [48/75/84]
b) 10(2) = [46/73/82]
c) 11(2) <> {47} because it's a Killer pair of Outies C78
d) Killer pair (58) locked in Outies C78 + 11(2) for C6
e) Using Outies R78 = 6(2): Innies B46 = 7(2) <> 7,8
f) ! 7 locked in 18(3) + 25(5) for B46 (Grouped X-Wing)
-> 18(3) = 7{38/56}; R45C7 <> 5,8
-> 7 locked for C78
g) R7C7 = 8 -> R6C7 = 4
h) 14(3) @ R6C5 = {257} -> R6C5 = 2
i) Innies B46 = [16/43/61]
j) Killer pair (58) locked in R4C6 + 11(2) for C6
k) 10(2) <> 2

3. C1234
a) 7(2) = {16} locked for R6+B5
b) Innies B35 = Outies B46 = 8(2) <> 4,8; R4C4 <> 2,7
c) Outies C12 = 10(2) = [73/82]
d) 5(2) = {23} locked for R7+B7

4. R12
a) 8(3) = {125} locked for B2 because {134} blocked by Killer pair (34) of 10(2)
b) Outies R12 = 10(2) = [64/73/82]
c) Outies R1 = 9(3) = 1{26/35} since {234} blocked by Killer pair (34) of 10(2)
d) 13(2): R2C2 <> 8
e) 8 locked in 14(3) @ R2 = {248} -> 2 locked for C4
f) Outies R12 = 10(2) <> 7
g) 13(2): R2C2 <> 6

5. C5678
a) Naked triple (367) locked in R245C7 for C7
b) 5 locked in R78C5 for B8
c) 11(3): 6{14/23} -> 6 locked for C8+B8; R78C8 <> 1,2
d) 6 locked in R4C57 for R4

6. B3
a) 16(3) <> 2

7. Rest is singles and simple cage sums.

Rating: Hard 1.0. I used Killer pairs and a Grouped X-Wing.

No problem! It's enough to have a WT for the V1 for now. We can always, if necessary, leave the V2 for a new "Unsolved" thread.


No, it was more to do with wanting to contribute content to this new site. But, of course, I would have liked to have seen more activity on the uA100.


Yes, it was no joy ride, but several previous Assassins (such as the A50, A60 and A71) were arguably tougher.

For me, the uA100 marked the end of an era. It appears that Sudoku has "come of age" in recent times, and that probably most people are less interested in doing puzzles to try and discover (increasingly rarer) new techniques and are instead more interested in just doing them for fun. For this reason, I suspect that the new Assassins will probably need to be in the 0.75 - 1.25 rating range. Puzzles of 1.5 rating or above are probably now better left for the (much-improved) automated solvers, which will no doubt remain a major source of interest in the coming months.

Whatever happens, I am sure that there will be several interesting discussions on this forum in the future. So, I'll definitely be sticking around, even if I end up only addressing a small audience at first. However, I'll also be pacing myself. In a way, I'm glad that the initial Sudoku hype is now over, because it created a lot of unhealthy addiction, resulting in many people (including Ruud?) suffering from sudden burn-out, never to be seen again! Hopefully, we can continue at a healthier pace in the future, even if we have to drop down a gear to do so.

_________________
Cheers,
Mike

I haven't yet tried either of these puzzles, in fact I haven't even set up diagrams yet because I've only just finished all the uA99s and still haven't finished uA100.

It shouldn't be any harder using my Excel worksheet than a standard 9 x 9 killer; the eliminations get done by me either way. I guess the hardest thing may be getting used to 2 x 4 blocks instead of 3 x 3 nonets.

Mike's table of combinations is welcome. However I think the easier way is to use Ruud's combination calculator and tick 9 as a forbidden number. That's what I'll do when I try one or both of these puzzles.

Hi folks,

Here is my walkthrough for the Cyclone V2:

Edit: Typos corrected (many thanks, Afmob!)

Edit2: Afmob (after going through my WT) also commented about the 1.75 rating being too high. I agree, but would still rate it as 1.5, because there's at least one important move in there that is difficult to see.

Edit3: Yet more typos corrected (muchas gracias, Andrew!)

_________________
Cheers,
Mike

I've just done Cyclone Killer V1. Thanks Mike for a fun puzzle.

As I'd expected, setting up the diagram wasn't difficult. It was easy to modify my normal Excel worksheet diagram.

Although I suggested in my earlier message that Ruud's combination calculator, with 9 ticked as a forbidden number, was the easiest way to get the combinations, I actually used Mike's table of combinations. Thanks for that table, Mike!

In a position similar to where Afmob found his grouped X-wing, I found a different grouped X-wing. It wasn't quite as direct as Afmob's one but mine also led to a fairly quick solution.

I agree with Afmob and rate Cyclone Killer V1 at Hard 1.0.

Here is my walkthrough. I originally used some combined cages but have replaced them with simpler steps which weren’t significantly slower.

Prelims

a) R23C2 = {58/67}
b) R2C67 = {28/37/46}, no 1,5
c) R34C3 = {28/37/46}, no 1,5
d) R3C56 = {14/23}
e) R56C6 = {38/47/56}, no 1,2
f) R6C34 = {16/25/34}, no 7,8
g) R67C7 = {48/57}, no 1,2,3,6
h) R7C23 = {14/23}
i) 8(3) cage in Octet 2 (O2) = {125/134}, 1 locked for O2
j) 18(3) cage at R4C6 = {378/468/567}, no 1,2

1. 36 rule on O2 3 innies R1C56 + R2C5 = 18 = {378/468/567}, no 2

2. 36 rule on R12 2 outies R3C24 = 10 = [64/73/82], no 5 in R3C2, R3C4 = {234}, clean-up: no 8 in R2C2
2a. Max R3C4 = 4 -> min R2C45 = 10, no 1 in R2C4
2b. Killer single 4 in R3C4 and R3C56, locked for R3, clean-up: no 6 in R4C3

3. 36 rule on C8 3 outies R138C7 = 8 = {125/134}, no 6,7,8

4. Killer pair 4,5 in R138C7 and R67C7, locked for C7, clean-up: no 6 in R2C6

5. 36 rule on C78 2 outies R24C6 = 12 = {48}/[75], no 2,3,6, no 7 in R4C6, clean-up: no 7,8 in R2C7
5a. R56C6 = {38/56} (cannot be {47} which clashes with R24C6), no 4,7
5b. Killer pair 5,8 in R24C6 and R56C6, locked for C6

6. 36 rule on C12 2 outies R57C3 = 10 = [64/73/82], R5C3 = {678}, no 1 in R7C3, clean-up: no 4 in R7C2

7. 1 in R2 locked in R2C138
7a. 36 rule on R1 3 outies R2C138 = 9 = {126/135}, no 4,7,8
7b. Max R2C1 = 6 -> min R1C12 = 10, no 1

8. 36 rule on R78 2 outies R6C57 = 6 = [15/24], clean-up: no 4,5 in R7C7
8a. R6C34 = {16/34} (cannot be {25} which clashes with R6C57), no 2,5
8b. Killer pair 1,4 in R6C34 and R6C57, locked for R6

9. 14(3) cage at R6C5 = {158/167/248/257} (cannot be 347/356} because R6C5 only contains 1,2), no 3
9a. R6C5 = {12} -> no 1,2 in R7C45
9b. Killer pair 7,8 in R7C45 and R7C7

10. 36 rule on R8 3 outies R7C168 = 11 = {146/236} (cannot be {245} which clashes with R7C23), no 5, 6 locked for R7
10a. Killer pair 3,4 in R7C168 and R7C23, locked for R7

11. 36 rule on C678 4 innies R1378C6 = 13 = {1237/1246} (cannot be {1345} which clashes with R56C6)
11a. Hidden killer pair 1,2 in R3C6 and R78C6 for C6, R78C6 cannot be {12} because 25(5) cage at R7C6 cannot contain both 1 and 2 -> R78C6 contains one of 1,2, R3C6 = {12}, clean-up: no 1,2, in R3C5
11b. R78C6 contains one of 1,2 -> no 1,2 in R8C345
11c. 25(5) cage at R7C6 = {13678/14578/23578/24568} (cannot be {34567} which doesn’t contain 1,2), 8 locked in R8C345, locked for R8

12. 36 rule on O7 3 innies R7C4 + R8C34 = 20 = {578}, locked for O7

13. 36 rule on O46 4 innies R456C5 + R6C7 = 13, R6C57 = 6 (step 8) -> R45C5 = 7 = {16/25} (cannot be {34} which clashes with R3C5), no 3,4,7,8, R45C4 = 8 = {17/35} (cannot be {26} which clashes with R45C5), no 2,4,6,8
13a. R45C45 = 15{27/36}

14. Grouped X-Wing for 5 in R45C45 and R7C45, locked for C45
14a. Killer triple 5,7,8 in R45C4, R7C4 and R8C4, locked for C4
14b. 8 in C4 locked in R78C4, locked for O7

15. 14(3) cage at R2C4 = {248/347}, no 6
15a. 7,8 can only be in R2C5 -> R2C5 = {78}
15b. 4 locked in R23C4, locked for C4, clean-up: no 3 in R6C3

16. 5 in O2 locked in 8(3) cage = {125}, clean-up: no 8 in R2C6
16a. 8 in O2 locked in R12C5, locked for C5

17. R8C4 = 8 (hidden single in R8)
17a. Naked pair {57} in R7C45, locked for R7 -> R7C7 = 8, R6C7 = 4, R6C5 = 2 (step 8), clean-up: no 5 in R45C5, no 3 in R6C4
17b. 5 locked in R45C4 (step 13a and step 13) = {35}, locked for C4 -> R7C45 = [75], R8C3 = 5

18. Naked pair {24} in R23C4, locked for C4, R2C5 = 8 (step 15)

19. Naked pair {16} in R6C34, locked for R6 and O5

20. 21(5) cage at R1C3 = {12378/12468/13467}
20a. 8 of {12378/12468} must be in R1C3 -> no 2 in R1C3

21. 36 rule on C1 3 outies R168C2 = 16 = {178/358/367} (cannot be {268/457} which clash with R23C2), no 2,4

22. 4 in C2 locked in R45C2 -> 16(3) cage at R4C2 = {457} (only remaining combination} -> R5C3 = 7, R45C2 = {45}, locked for C2, clean-up: no 8 in R3C2, no 3 in R34C3

23. Naked triple {358} in R5C4 + R6C12, locked for O5 -> R5C12 = [24], R4C2 = 5, R45C4 = [35]

24. 11(3) cage in O7 = {146} (only remaining combination), locked for O7 -> R7C23 = {23}, locked for R7
24a. R8C2 = 1 (hidden single in C2}, naked pair {46} in R78C1, locked for C1

25. Naked pair {38} in R6C12, locked for R6 and 21(5) cage at R3C1 -> R6C68 = [57], R5C6 = 6

and the rest is naked singles

Maybe I'll now try V2.

Cyclone Killer #2 was a really challenging puzzle. It took me a few sessions but I eventually got it out.

Mike's step 15b was a nice one; it really broke the puzzle open. I also missed Mike's grouped X-wing (step 12a) but found a couple of other ones. I realised later that my step 27 is the complement of Mike's step 12a.

Mike rated this puzzle at 1.5, after feedback from Afmob. I agree with that. It was Hard 1.5 the way I solved it.

Here is my walkthrough. I hope I've made the more difficult moves, particularly the ones that cover two octets, clear enough. Edit: Step 45 re-phrased for clarity.

Edit2: Mike pointed out that there were flaws in the original step 37 and the first part of step 40, both now in red. Fortunately I found a workaround for step 37 and was able to include Mike's suggestion for the first part of step 40. Mike also gave a quicker way to the first placement, which I've included after step 32. Thanks for all of those, Mike!

Prelims

a) R23C2 = {16/25/34}, no 7,8
b) R2C67 = {16/25/34}, no 7,8
c) R34C3 = {38/47/56}, no 1,2
d) R6C34 = {48/57}, no 1,2,3,6
e) R67C7 = {28/37/46}, no 1,5
f) R7C23 = {17/26/35}, no 4,8
g) 17(3) cage at R4C2 = {278/368/458/467}, no 1
h) 7(3) cage in Octet 8 (O8) = {124}, locked for O8, clean-up: no 6,8 in R6C7

1. 36 rule on C8 3 outies R138C7 = 8 = {125/134}, 1 locked for C7, clean-up: no 6 in R2C6

2. 36 rule on R12 2 outies R3C24 = 7 = {16/25/34}, no 7,8 in R3C4

3. 36 rule on O35 4 innies R3C24 + R45C4 = 13, R3C24 = 7 (step 2) -> R45C4 = 6 = {15/24}, no 3,6,7,8
3a. R45C4 = 6 -> R45C5 = 11 = {38/47/56}, no 1,2

4. 36 rule on R78 2 outies R6C57 = 8 = [17/53/62], R6C5 = {156}, no 4 in R6C7, clean-up: no 6 in R7C7
4a. Killer pair 2,3 in R138C7 and R67C7, locked for C7, clean-up: no 4,5 in R2C6

5. 36 rule on C12 2 outies R57C3 = 7 = [25/43/52/61], no 7,8, no 3 in R5C3, no 6 in R7C3, clean-up: no 1,2 in R7C2

6. 36 rule on C78 2 outies R24C6 = 3 = {12}, locked for C6, clean-up: no 4 in R2C7, no 7,8 in R3C5, no 7,8 in R56C6

7. 17(3) cage at R4C2 = {278/368/458/467}
7a. 2 of {278} must be in R5C3 -> no 2 in R45C2

8. 36 rule on R1 3 outies R2C138 = 16 = {178/358/367/457} (cannot be {268} which clashes with R2C67), no 2

9. 26(5) cage at R7C6 = {23678/34568} (cannot be {14678/24578} which clash with 7(3) cage in O8), no 1
9a. R8C34 must contain 2 or 4

10. 1 in 7(3) cage in O8 must be in R8C78 (R8C78 cannot be {24} which clashes with R8C34), no 1 in R7C8
10a. 1 in O8 locked in R8C78, locked for R8
10b. Killer pair 2,4 in R8C34 and R8C78, locked for R8

11. 15(3) cage in O7 = {168/258/267/348/357/456}
11a. 1,2,4 of {168/258/267/348/456} must be in R7C1 -> no 6,8 in R7C1

12. 36 rule on C1 3 outies R168C2 = 11 = {128/137/146/245} (cannot be {236} which clashes with R23C2)
12a. 5,6,8 in {128/146/245} must be in R8C2 -> no 5,6,8 in R16C2

13. 16(3) cage in O2 = {178/358/367/457} (cannot be {268} which clashes with R2C67), no 2
13a. 1 of {178} must be in R1C7 -> no 1 in R12C8

14. 21(5) cage at R3C7 = {12567/13458/13467/23457} (cannot be {12378} which clashes with 16(3) cage in O2, cannot be {12468} which clashes with 8(3) cage in O8)
14a. 16(3) cage in O2 (step 13) = {358/367/457} (cannot be {178} which clashes with 21(5) cage at R3C7), no 1

15. R138C7 (step 1) = {125/134}
15a. 5 of {125} must be in R1C7 -> no 5 in R3C7

16. 36 rule on R8 3 outies R7C168 = 12 = {147/246/345} (cannot be {138/156} because R7C8 only contains 2,4, cannot be {237} which clashes with R7C23), no 8, 4 locked for R7
16a. 1 of {147} must be in R7C1 -> no 7 in R7C1

17. 26(5) cage at R7C6 (step 9) = {23678/34568}, 8 locked in R8C3456, locked for R8

18. 15(3) cage in O7 (step 11) = {267/357/456}, no 1
[I missed a clean-up (using step 16) here, see comment after step 26.]

19. 8 in C2 locked in R45C2, locked in 17(3) cage (step 7) = {278/368/458}
19a. 6 of {368} must be in R5C3 -> no 6 in R45C2

20. R168C2 (step 12) = {137/146/245}
20a. R23C2 = {16/25} (cannot be {34} which clashes with R168C2), no 3,4, clean-up: no 3,4 in R3C4 (step 2)

21. 36 rule on R12 3 innies R2C245 = 13 = {148/238/247/346} (cannot be {157/256} which clash with R2C67), no 5, clean-up: no 2 in R3C2, no 5 in R3C4 (step 2)
21a. R2C2 = {126} -> no 1,2,6 in R2C45

22. Hidden pair {12} in R1C5 and R2C6 for O2 -> R1C5 = {12}

23. 36 rule on O2 3 innies R1C56 + R2C5 = 13 = {148/238/247} (cannot be {157/256} which clash with R2C67, cannot be {346} because R1C5 only contains 1,2), no 5,6

24. 8 in O7 locked in R7C4 + R8C34
24a. 36 rule on O7 3 innies R7C4 + R8C34 = 13 = {148/238}, no 5,6,7
24b. R8C34 must contain 2 or 4 (step 9a) -> no 2 in R7C4

25. 8 in R7 locked in R7C457
25a. 36 rule on R78 3 innies R7C457 = 16 = {178/358}, no 6
25b. 5 of {358} must be in R7C5 -> no 3 in R7C5

26. 1 in R7 must be in R7C23 = [71] or in R7C457 = 1{78} -> 7 locked in R7C257, locked for R7
[I then realised that I only got this because I’d missed the clean-up after step 18. I’ve left it like this because it’s an interesting step.]

27. 2 in C56 locked in R13C5 and R24C6, locked for B24

28. Hidden killer pair 1,2 in R6C57 and R56C8 for O6 -> R6C57 and R56C8 must each contain one of {12} (R56C8 cannot be {12} which clashes with R78C8)
28a. R6C57 (step 4) = [17/62] (cannot be [53] which doesn’t contain 1 or 2), clean-up: no 7 in R7C7
28b. Killer pair 1,2 in R56C8 and R78C8, locked for C8
28c. 4 of 7(3) cage must be in R78C8 (R78C8 cannot be {12} which clashes with R56C8), no 4 in R8C7
28d. 4 in O8 locked in R78C8, locked for C8

29. Hidden grouped X-Wing in 1 for C78 -> 21(5) cage at R3C7 and 7(3) cage in O8 must both contain 1
29a. 21(5) cage at R3C7 (step 14) = {12567/13458/13467} (cannot be {23457} which doesn’t contain 1)
[This was there after step 14a but I’ve only just spotted it. Since it doesn’t lead to any immediate candidate eliminations I haven’t moved it.]

30. 16(3) cage in O2 (step 14a) = {358/367} (cannot be {457} which clashes with 21(5) cage at R3C7), no 4, 3 locked for O2

31. R138C7 (step 1) = {125/134}
31a. 4 of {134} must be in R3C7 -> no 3 in R3C7

32. 36 rule on R123 4 innies R3C1378 = 20 = {1478/3458/3467} (cannot be {1568/2468/2567} which clash with R3C24, cannot be {2378} because R3C7 only contains 1,4), no 2, 4 locked for R3, clean-up: no 5 in R3C56

[Mike pointed out that from here there is a much quicker route to my first placement.
33. 14(3) at R6C5+R7C45 = [185/617/635]
33a. R67C5 = {(5/6)..}
33b. -> {56} combo blocked for h11(2) at R45C5 (step 3a)
33c. -> no 5,6 in R45C5
34. 5 in C5 locked in R78C5 for O8
35. 5 in C6 locked in 9(2) at R5C6 = {45}, locked for C6 and N6
36. HS in O2 at R2C5 = 4
I'm not sure why I didn't look at the permutations for the 14(3) cage at R6C5; I'd looked at them for R7C457.]

33. R7C457 (step 25a) = {178/358}
33a. 5,7 can only be in R7C5 -> R7C5 = {57}

34. 4 in C5 can only be in R2C5 or R45C5
34a. If 4 in R45C5, then R45C5 = {47}
34b. -> no 7 in R2C5

35. R2C245 (step 21) = {148/238/247/346}
35a. 13(3) cage at R2C4 = {148/238/247/346}
35b. 4 of {148} must be in R2C5 (R23C4 cannot be [41] which clashes with R45C4)
35c. 3,7 of {247/346} must be in R2C4
35d. -> no 4 in R2C4

36. Combined cage R12368C2 = 18 = {12357/12456}, 5 locked for C2, clean-up: no 4 in R5C3 (step 19), no 3 in R7C3
36a. R34C3 = {38/47} (cannot be {56} which clashes with R57C3), no 5,6

37. Killer singles 8 in R45C2 (step 19), R34C3 or R6C34, locked for O35
37a. 19(5) cage at R3C1 = {12367/12457/13456}

[Mike pointed out that there is a flaw in step 37. Because of the geometrical arrangement it’s possible for R34C3 to be {47} with R6C34 = [57] when there is an 8 in the 19(5) cage = {12358}. Fortunately I found a workaround which showed that this combination is impossible.]

37. 8 locked in R45C2 (step 19)
37a. If R34C3 or R6C34 contain 8 => no 8 in 19(5) cage at R3C1 = {12367/12457/13456}
37b. If neither of R34C3 or R6C34 contain 8 then both must contain 7 => R34C3 = {47} => R6C34 = [57] => 19(5) cage at R3C1 must contain 8 = {12358} with 5 in R34C1 => R3C24 = {16}, locked for R3 => R3C7 = 4 => R3C56 = [27] -> R3C57 clash with R3C3
37c. -> R3C1 = {12367/12457/13456}, no 8

38. 8 in C1 locked in R12C1, locked for O1
38a. 13(3) cage at R1C1 = {148/238}, no 5,6,7

39. R2C245 (step 21) = {238/247/346} (cannot be {148} because R2C4 only contains 3,7), no 1, clean-up: no 6 in R3C2, no 1 in R3C4 (step 2)

40. Hidden killer singles 7 in 19(5) cage at R3C1, 17(3) cage at R4C2, R34C3 and R6C34 for O35, R34C3 or R6C34 contain 7 -> 19(5) cage at R3C1 or 17(3) cage at R4C2 must contain 7
40a. 2 and 7 are linked in 19(5) cage at R3C1 (step 37a) and 17(3) cage at R4C2 (step 19) -> 19(5) cage at R3C1 or 17(3) cage at R4C2 contains 2 and 7
40b. Hidden killer singles 2 in 19(5) cage at R3C1, 17(3) cage at R4C2 and R345C4, 19(5) cage at R3C1 or 17(3) cage at R4C2 contains 2 -> R345C4 must contain 2
40c. 2 locked in R345C4, locked for C4

[After checking my workaround for step 37, Mike pointed out that there is a similar flaw in this step and in this case provided a workaround using the same basic approach that I’ve put into the first part of step 40.]

40. Hidden killer pairs 7,8 in 19(5) cage at R3C1, 17(3) cage at R4C2, R34C3 and R6C34 for O35, R34C3 and R6C34 must contain two occurrences of 7,8 -> 19(5) cage at R3C1 and 17(3) cage at R4C2 must contain two occurrences of 7,8 of which one is 8 locked in R45C2 so either 19(5) cage at R3C1 or 17(3) cage at R4C2 contains 7
40a. 2 and 7 are linked in 19(5) cage at R3C1 (step 37a) and 17(3) cage at R4C2 (step 19) -> either 19(5) cage at R3C1 or 17(3) cage at R4C2 contains 2 and 7
40b. Hidden killer singles 2 in 19(5) cage at R3C1, 17(3) cage at R4C2 and R345C4, 19(5) cage at R3C1 or 17(3) cage at R4C2 contains 2 -> R345C4 must contain 2
40c. 2 locked in R345C4, locked for C4

41. R7C4 + R8C34 (step 24a) = {148/238}
41a. 2 of {238} must be in R8C3 -> no 3 in R8C3
41b. 4 of {148} must be in R8C3 (R78C4 cannot be [14] which clashes with R45C4], no 8 in R8C3, no 4 in R8C4
41c. 8 in O7 locked in R78C4, locked for C4, clean-up: no 4 in R6C3

42. Killer pair 2,6 in R2C2 and R2C67, locked for R2

43. R2C138 (step 8) = {178/358/457}
43a. 4 of {457} must be in R2C1 -> no 4 in R2C3

44. 36 rule on C123 4 innies R1268C3 = 18 = {1467/2358/2457} (cannot be {1278/2367} which clash with R34C3, cannot be {1368} because R8C3 only contains 2,4, cannot be {1458/3456} which clash with R57C3)
44a. 6 of {1467} must be in R1C3 -> no 1 in R1C3
44b. 2,4 of {2457} must be in R18C3
44c. Combining steps 44a and 44b, no 7 in R1C3

45. 13(3) cage at R2C4 (step 35a) = {238/247/346}
45a. Hidden killer triple 1,2,3 in R23C4, R45C4 and R78C4 for C4, R45C4 must contain 1 or 2, R78C4 must contain 1 or 3 -> R23C4 can only contain one of 2,3 -> no 8 in R2C5 (step 45)
45b. R2C5 = 4, R23C4 = [36/72] (step 45), clean-up: no 7 in R45C5
45c. Killer triple 1,2,3 in R23C4, R45C4 and R78C4, locked for C4
45d. R2C5 = 4 -> R1C56 = [18/27] (step 23)

46. 5 in O1 locked in R1C34 + R2C3 -> 23(5) cage at R1C3 must contain 5
46a. 23(5) cage at R1C3 = {12578/13568/23567} (cannot be {13478/23468} which don’t contain 5, cannot be {14567} which clashes with R1C56), no 4
[I could now make further candidate eliminations but the next step is more direct.]

47. 4 in O1 locked in R1C12
47a. 13(3) cage at R1C1 (step 38a) = {148} (only remaining combination), locked for O1

48. Grouped X-Wing on 1 in 13(3) cage at R1C1 and 19(5) cage at R3C1, locked for C12 -> R3C2 = 5, R2C2 = 2, R2C6 = 1, R2C7 = 6, R2C1 = 8, R4C6 = 2, R1C5 = 2, R1C6 = 7 (step 45c), R2C4 = 7 (step 39), R3C4 = 2 (step 45a), clean-up: no 4 in R45C4, no 1 in R5C4 (both step 3)
48a. R45C4 = [15], R16C4 = [64], R6C3 = 8, clean-up: no 3 in R34C3, no 6 in R45C5 (step 3a)

49. R1C8 = 8 (hidden single in R1)

50. R7C3 = 1 (hidden single in C3), R7C2 = 7, R7C5 = 5, R56C2 = [31], R1C12 = [14], R4C2 = 8, R45C5 = [38], clean-up: no 6 in R3C56

and the rest is naked singles

the cyclone cages do make an interesting picture...

wouldnt it work out better with an odd number grid..
that would give it a center to start from

9x9 11x11 or 13x13 ?

oh, some of those need to be jigsaw killers could get a double whirl in the nonets (trixidecinete?)

How nice. A puzzle named after me.

(Seriously, I've used the name "Cyclone" since 2001.)

I stumbled across this board after some linkage leading me through the inactive sudocue.net - what happened to that site? Is it not being updated any further? Should I save all the puzzles I can before it goes away?

Cyclone