Here is a valid example of the circle rule:
In the example above, you can't put a 3 in the cell west of the 2, since that would mean that the two has three unique kropki neighbors.
Solution code: Digits from last row (9:th), no digits or spaces.
on 19. March 2023, 18:09 by KyleBaran
I understood the rules but wasnt clever enough to make logical deductions so I had to bifurcate to solve some parts. Seems the knight rule interacts with the bubbles wonderfully. I enjoyed it and hope it gets a feature on CTC
on 12. March 2023, 10:20 by zhall12570
Wow! Great puzzle. Very nice solve path
@zhall12570 Thanks! Glad you enjoyed it. /Andreas
on 11. March 2023, 20:37 by Nylimb
Thanks for the clarification, and for the difficult puzzle. I bifurcated several times, so I probably missed the intended solution path.
on 11. March 2023, 07:53 by andreasv
@Nylimb Thanks for asking for clarifications. I have added some more info and an example. Hope this helps in understanding the rule.
on 11. March 2023, 07:44 by Nylimb
I'm not sure what the circle rule means. Are the "orthogonally connected digits" supposed to be in a kropki relation with the digit in the circle, or with each other? Also, what does "unique" mean here?
E.g. if a 2 had orthogonal neighbors 1,1,3,4 would that count as 4 neighbors in a kropki relation with 2, or just 3 since the 1 only counts once? Or would there just be 1 kropki relation, between the 3 and the 4?