>This has been used in the past by a devious creator that built his sudoku in such a way that the final n numbers to be filled led to two deduction paths; one l

>This has been used in the past by a devious creator that built his sudoku in such a way that the final n numbers to be filled led to two deduction paths; one leading to a single solution, the other to two possible solutions. I don't see how this differs from there being three solutions, thereby not following the unique solution role. Like, what is functionally the difference between picking the path that leads to one solution rather than two, and just picking one of the two solutions at the end?