dailysudoku.com

[Ali Al-Aref]

I very often find variations in the level of diffuclty in some of these puzzles although they are rated the same. For example, 23-May-2006,
9-May-2006, and 2-May-2006 (all classic) are all rated "very hard" but
I found that solving 23-May-2006 was a lot easier than the other two.

So far I have been able to solve all the puzzles that I have tried to solve. Sometimes the very hard ones take a very long time to do.

[David Bryant]

Hi, Ali!

This topic has been discussed extensively. Briefly, Samgj uses a computer program to set the ratings -- if a puzzle has 3 or more "choke points" it's rated very hard.

The thing is, some of the logic steps necessary may seem easier to you than others. As I recall, all three of the puzzles you mentioned contain an "X-Wing" formation. Sometimes that's easier to spot (for me) than at other times ... it depends on how close together the four corners of the X-Wing are.

If you want a harder puzzle, try this other site. dcb