This is my first post so I don't know if I'm going about this the correct way.
I have a concern about puzzles that have multiple solutions (invalid?).
I just got the Dell "Original Expert Sudoku" and tried the 3 puzzles at the beginning of the Expert section.
2 of the 3 were "ambiguous" in that there were two valid solutions (I tried both).
I find this extremely frustrating because I don't know when a puzzle is invalid or I just haven't figured it out yet.
I'm wasting time on invalid puzzles.
Being a big source of puzzles I would expect Dell to do better.
Is there any way to put pressure on Dell to validate their puzzles?
Is there a good source of verified valid puzzles?
A list of good sources in this forum would be great.
Thanks