The New Sudoku Players' Forum

[zebedee]

I wonder whether any Sudoku fans who are brighter than me might be able to help me with a small clue as to the next step on the Very Hard shown below.

* 4 * * 3 7 2 6 *
1 2 * * * * * 7 3
* 3 7 2 * 8 9 * *
* * * * * 3 * * 6
2 6 * * * * 7 3 4
4 * 3 7 * * * * *
* * 2 5 * 1 3 * *
* 5 * * * * * * 2
* 1 * * 9 2 * 5 *

I've been puzzling over it for days without any joy and I suspect I'm missing something really obvious. Any help would be most gratefully received.

Regards to all.


Zeb

[Animator]

There is an X-wing in the number 4.

When you see that, and do all things this X-wing imply (as in, remove candidates from cells), then there will be only one place for the number 4 in box 5.

[Animator]

Note though that there is also an X-wing in the numer 6...

[Guest]

wat do you mean by an x wing

[chipe]

How about a hint: what are the 4 verticies of the x-wing?
Thanks

[joolslee]

The x-wing of 4's - R3C5/C8 and R7C5/C8

[chipe]

thanks joolslee, I see it now, though the 4's x-wing didn't seem to accomplish much. Working with the 6's x-wing (row 3, columns 1 and 5; and row 7, columns 1 and 5) gave better results. Thanks again. ... ...... I finished it.

[zebedee]

Many thanks for the X-wings tips Animator. I have now managed to solve the puzzle. The X-wing in the 6s was the most useful hint.

Thanks again.

Zeb