Logic Masters Deutschland e.V.

I recently played the CtC Domino Sukoku package in their new app which motivated me to set a Kropki Pairs puzzle after pausing with setting for a while. I am pretty happy with the result, hope you like it too.

❶ Standard Sudoku rules apply
❷ Kropki Pairs: white dots contain consecutive digits, black dots contain digits with a 1:2 ratio. No negative constraints, so not all dots are given

Play online: f-puzzles | CtC app

1. Cells in R2,3 are connected with 8 white dots taking all 8 even numbers of the two rows, therefore the remaining two cells must be odd (r2c3 and r3c9)
2. Of the two cells R2c12, one must be even and one must be odd. Hence r3c3 must be odd too.
3. Now, where can 2 go in row 3? A 2 in c12r3 needs a 3 in c12r2, leading to a 1 in r3c3 and a two in r3c4. The only place for a 2 in the row is r3c4.
4. R4c49 are a 2-6 pair. Two more even numbers are needed for the white dots in row 4. R4c456 contains only odd numbers and the black dot in box 5 can be resolved.
5. The dots in row 4 contain either a 4/5 or a 7/8/9. So r4c6 is a naked single 7.
6. Some numbers can be resolved, leading to r2c45 can only be a 7/8/9 pair that must contain an 8.
7. This 8 on row 2 affects where 9 can go in box 1 (only in r3c3)
8. Two must now go into r1c12 which resolves the black dots between row 3 and 4. Also, 8/9 in r3 must go into r3c78.
9. As the black dots in box 8 are 1/2 and 4/8, the black dot in box 9 can only be 2/4.
10. This due to this 2/4 pair in c9 and the 2/5 pair in box 1 r1c9 can only be 1/7. If it is one r1c7 would be 1 too. So it can only be 7, creating an 8/9 pair in r67c9.
11. Because r6c9 can only be 8/9, r4c78 must be 4/5. Now boxes 2, 3, 5, and 6 can be resolved.
12. Now, two must be in r7c12. If either of r7c12 is a 3, a 2 is placed in box 1 in the other column leaving no place for a 2 on row 7. Therefore r7c12 is 1/2.