The New Sudoku Players' Forum

[Bernard Stay]

It looked to me as though the (only) way to solve this was to invoke an X-wing. Is that so? and are we to expect this do you think?

Thanks.

[Karyobin]

Post the puzzle and I'll let you know.

[Bernard Stay]

Post the puzzle and I'll let you know.

Thanks K. Here 'tis:

*9*|**2|5*3
**1|3**|*9*
***|**6|**1
--------------
**9|***|*8*
***|251|***
*5*|***|2**
--------------
4**|9**|***
*1*|**7|4**
9*6|1**|*7*

[Karyobin]

Yup, I concur. The X-wing crops up in rows & columns 2 & 9 in 2's. No other way past this point as far as I can see. Looks like the Times is moving to the next level.

BRING IT ON!!!

[PaulIQ164]

Vaguely irritating that they have to do it on Sundays when I don't get the paper, but nver mind.

[David B]

I've got a little further and after locating the straightforward entries found a triple in row 9 which lead to 145 in columns 456 but I'm still struggling with x-wings and the reference to rows & columns 2 & 9.

I have 2 8 in row 9 column 9, and 2 6 8 in row 7 column 9 am I in the right place and where do I look next.

[simes]

Look where 2 can go in rows two and nine. There are only two possibilities, and they're both in the same columns. This is the xwing.

Both rows two and nine must each have a 2, but they can't be in the same column. So how many places can they go? We've determined that the 2 in columns 2 and 9 must be in rows 2 and 9. So we can eliminate any other 2s in these columns. I suspect that's as clear as mud

Simes

[David B]

Thank you Simes, your explanation is clear.

I may be missing something fundamental but I can see the two possibilities in row 9, but I have three possibilities in row 2: 2,9 and 1. I have reached
*9*|*12|5*3
**1|3**|*9*
***|596|**1
--------------
**9|***|*85
***|251|9**
*5*|**9|2**
--------------
4**|9**|***
*1*|**7|4*9
9*6|145|*7*

It looks to me as if row 2 column 1 could be 2, 5, 6 , 7 or 8

[simes]

But how many cells in row 2 can be 5?

Simes

[David B]

Simes - thanks too obvious but I missed it!