The New Sudoku Players' Forum

[possum]

I cannot get further than this with this puzzle:

*72 | 451 | *9*
*4* | 63* | 71*
13* | 7*8 | 4*5
------------------
*** | 2** | *3*
3*4 | *** | 6**
*6* | **3 | ***
------------------
9** | 38* | 147
*1* | 5*4 | *8*
48* | 917 | 5**

Any tips gratefully received.

[shakers]

There's only one place for the 2 in col 7.

STOP READING NOW IF YOU WANT TO WORK IT OUT FOR YOURSELF. Otherwise:

It has to go in r6c7 - it cannot go in r2c7 or r4c7 obviously. It cannot go in r8c7 because the only possible place for a 2 in r9 is either r9c8 or r9c9 so 2 can be eliminated from r8c7.

[possum]

Thank you shakers. I can't believe I missed the fact that the 2 had to be at the bottom of box 9. Thanks again.

[shakers]

No problem - I know what it can be like staring at the puzzle for ages. Another pair of eyes is often all that's needed.

[SteveF]

If it's any consolation, I spent quite some time over two days at the end of last week before spotting the above. In fact I solved the following day's fiendish before returning to this one!

Not for the first time, having spotted it you wonder why you have missed it for so long.

[shakers]

I feel as if I've noticed that when the only move forward is in column, row, or box 8 or 9 it can take an awful lot longer to find than if it's in col, row, or box 1 or 2.

Is this something that could be put in when the puzzle's designed, or am I just imaging things now..?

Maybe when going through possibilities it would be worth working 9 to 1 for a change?!

[Guest]

I have posted the steps that show the logic for
the 2 in r6c7.

See Example #7 @

http://www.easysurf.cc/su-doku.htm