gman and jackt, I have an answer to how to solve the middle square of column 1 without green (yesterday's puzzle at the point gman got stuck). Consider the cell at row 3, column 6 (R3C6). If it is not a 9 then the cell at R6C6 must be a 9. If the cell at R6C6 is a 9 then so must the cell at R5C1 be a 9. That means either the cell at R3C6 is a 9 or else the cell at R5C1 is a 9 and therefore the cell at R3C1 can never be a 9. If the cell at R1C1 is never a 9 then the cell at R5C1 must be a 9.
Oops... the last sentance below should be: If the cell at R3C1 is never a 9 ... (not R1C1).
Done - no greens. JackT - I don't show my crack to just anyone! LOL I have no idea what you're talking about? I just do these puzzles for fun and not to prove anything. I know others are much better at them than I am but I'm hoping these will help keep my brain from atrophying later in life - that's my main goal. Have fun and keep your brain supple.
done, no greens
finished ... no greens ... fun puzzle
Gretchen a better way to keep your brain from atrophy is learning to play Go.
Did Thursday's Hard after giving it a two day rest.