The twins look identical but if you get to know them better then you will find out they are quite different. Both follow the traditional Rundweg rules (8x8 grid, with the given digits), further they are also both 4x4 Sudokus (in the large cells containing 4 Rundweg cells each) with the numbers 1 to 4 in every row, column and quadrant of the puzzle.
For the first twin, the sudoku numbers are equal to how many of the 4 rundweg cells are INSIDE the Rundweg.
For the second twin, the sudoku numbers are equal to how many of the 4 rundweg cells are OUTSIDE the Rundweg.
Solution code: The size of the areas outside each rundweg, clockwise starting in the top left. First for the first twin, then for the second.
on 13. November 2011, 22:12 Uhr by kiwijam
I found the first twin here the hardest of all the family members in the series...
on 8. May 2011, 13:08 Uhr by rob
Sehr schön. Die Varianten unterscheiden sich deutlich mehr, als die symmetrische Beschreibung vermuten lässt.
on 30. October 2010, 05:57 Uhr by Richard
Brilliant puzzle! Daughter one gave much more problems as her sister...
on 16. October 2010, 13:09 Uhr by pin7guin
Absolut genial! Haben diese Zwillinge auch noch Geschwister? :)
on 14. October 2010, 21:00 Uhr by CHalb
Good idea and very well done.
on 12. October 2010, 10:07 Uhr by CHalb
It's a great puzzle. I'm half way through. But I had a big problem in understanding the rules. Not because of the text but because of the diagram. The four sudokuareas should be marked with thicker lines.
@CHalb: Fixed. I didn't mark them before since they are not really necessary, the solution is unique even without them.
on 5. October 2010, 11:21 Uhr by flaemmchen
Ist jemand so freundlich und erklärt mir die Anleitung auf Deutsch? Das mit den Sudokuzahlen habe ich nicht verstanden :-((
on 4. October 2010, 10:49 Uhr by Luigi
Das war eine knifflige, aber schöne Herausforderung!
on 2. October 2010, 18:22 Uhr by Mody
Really great :)
on 2. October 2010, 17:02 Uhr by ibag
Great construction! Thank you!
on 2. October 2010, 11:39 Uhr by Alex
nice new idea and tricky!
on 2. October 2010, 11:38 Uhr by pokerke
It would be nice to make a bigger version of this puzzle (not necessarily a twin), maybe even a full 9x9 Sudoku, which would be a 27x27 Rundweg.
I haven't patented the idea so anyone is of course free to make as many as they want ;-).
on 1. October 2010, 21:06 Uhr by SilBer
I liked it very much!! LG Silke
on 1. October 2010, 19:39 Uhr by Statistica
Wow! Wonderful idea!