simon_blow_snow wrote:
I think for the hands variant, you can try positioning 9 givens in various known non-repeatable regions and compare their solvability. So far I found 3 regions allowing the easiest solving path: R1, N5, and the "hand" from R1C5. They each need only singles & intersections to solve.
I see, You're using the power of 9 clues in a heavily constrained puzzle.
With heavily constrained puzzles where an 8 clue puzzle is easily achievable (like the AK AN variant), your method is one clever way of making some difficult puzzles easier. With so many regions to choose from it can be tedious though. I'm not sure that it is a guranteed success either.
I'm no expert on advanced solving without pencilmarks ... You can read the following thread for ideas though
http://forum.enjoysudoku.com/solving-without-pencilmarks-t3640.html