The New Sudoku Players' Forum

[angelog1]

Here is where I am. What is my next move & why?

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

[Shazbot]

Not sure how far you've got in eliminating candidates.

Code: Select all

 *-----------------------------------------------------------------------*
 | 1458    345   13458   | 1678    2     134678  | 14568   56    9       |
 | 9       24    7       | 5       1468  1468    | 1468    3     2468    |
 | 1458    6     123458  | 18      9     1348    | 1458    7     2458    |
 |-----------------------+-----------------------+-----------------------|
 | 57      8     359     | 4       156   167     | 569     2     356     |
 | 2       1     6       | 3       58    9       | 7       4     58      |
 | 457     345   3459    | 678     568   2       | 5689    1     3568    |
 |-----------------------+-----------------------+-----------------------|
 | 1456    9     1245    | 126     146   146     | 3       8     7       |
 | 468     7     48      | 689     3     5       | 2       69    1       |
 | 3       245   12458   | 12689   7     1468    | 4569    569   456     |
 *-----------------------------------------------------------------------*


You have locked candidates (4) in row 8 as well as box 9
Again, locked candidates (5) in box 9
Now you should be able to place a few numbers.
If you get stuck again, look for an x-wing on 9s.
From there, it just unraveled with hidden and naked singles.

[masb]

Numbler (http://www.axcis.com.au/numbler) finds as a first step "Box Row @ 9> r9c2 r9c2=2 r9c3x4 r9c3x5 r9c6x4", so box 9 has 4s and 5s only on row 9 so they can be eliminated from other cells on row 9. The solution is simple from there with no x-wing needed.

[Spider]

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