The New Sudoku Players' Forum

[apaddobs]

Please help with any specific technique that comes to our rescue in solving this.

[SpAce]

Please help with any specific technique that comes to our rescue in solving this.

I don't see anything really simple that solves this. The simplest technique available is a W-Wing but it doesn't really help. Something slightly more complicated is needed. For example:

Code: Select all

...7..4...5..92......3.5..25.7...14..8..1..2..62...5.97..8.3......97..6...3..6...
.--------------.-----------.-----------------.
| 23  a2[3] 9  | 7  8   1  | 4     5     6   |
| 4    5    18 | 6  9   2  | 78    3     178 |
| 6    7    18 | 3  4   5  | 89    189   2   |
:--------------+-----------+-----------------:
| 5    9-3  7  | 2  6   89 | 1     4   d(3)8 |
| 39   8    4  | 5  1   79 | 6     2     37  |
| 1    6    2  | 4  3   78 | 5     78    9   |
:--------------+-----------+-----------------:
| 7    149  6  | 8  25  3  | 29    19    45  |
| 28  b12   5  | 9  7   4  | 3     6    c18  |
| 89   49   3  | 1  25  6  | 2789  789   45  |
'--------------'-----------'-----------------'

XY-Chain:

(3=2)r1c2 - (2=1)r8c2 - (1=8)r8c9 - (8=3)r4c9 => -3 r4c2; stte

...or the same as an ALS-XZ (X=1,Z=3):

(3=2'1)r18c2 - (1=8'3)r84c9 => -3 r4c2; stte

[docjohn]

Locked candidate (2) in row 8