ND’s killer sudoku puzzles
I’ve put these all in one spot. Warning: I generally try to make these are hard as possible; these are not good puzzles to learn the ropes with (for which, I’d recommend the Times website or book). I haven’t graded these, but they’re all pretty difficult (Times’ “Tough” to “Deadly”), with #4, #6, #6-alt, #7 and #9 the hardest (very very deadly!).
#1
A much harder variant of #6 (HEERE BEE DRAGONS!):
Killer 10 (for James Hirschfeld):
