## Previously Solved...but now I'm stuck!

Advanced methods and approaches for solving Sudoku puzzles
This one was really difficult.

But after following tso's advice, look at the 1's. If you look at columns 3,4,6 and 7, you can see that they have candidate 1 only for rows 1,3,6 and 9.

This allows you to eliminate 1's in rows 1,3,6 and 9 for all other columns. After having made that elimination, you can place a 1. From there you can continue.

There is a similar pattern in 5's, columns 2,8 and 9. But that one only gets you one step ahead.
Anette

Posts: 55
Joined: 09 June 2005

I corrected my typo in my original post -- sorry about that. However, after following all the clues upto and including the x-wing, there is nothing but hidden and naked singles.

-- Only one place for a "1" in box 4,
-- Row 9 column 1 can has only one possibility, etc.
tso

Posts: 798
Joined: 22 June 2005

Thanks, tso - following your advice, I did complete the puzzle on Monday but my userid had disappeared and I have had to re-register.
pch

Posts: 1
Joined: 13 September 2005

I missed eliminating one candidate based on the X-wing - no wonder it was difficult. Thanks tso for pointing that out!