Thank you SamanthaJoy for pointing me to the expert from March 29, 2013. That was a toughie!
Yesterday's easy: 17.
Difficulty score 20. No green.
I just can't get that one. I've tried every trick and technique I know. It's frustrating beyond words.
Try using greens, but only greens where there are only two possibilities in each of the 9 boxes.
Even with greens, it's not easy. I would suggest identification of impossibilities by testing the results of different choices. Some people won't do it because they call it guessing, but it's a valid mathematical technique I learned more than 50 years ago under the Latin name reductio ad absurdum.
Wild guesses are not the same thing. What makes the difference is keeping track of what you have tested and proved to be impossible.
Finished the [expletive deleted]/ Time to move on.