The New Sudoku Players' Forum

[bananafish]

Hi folks,

Please help with the following puzzle. I can't find figure out a strategy to solve the next number.

Thanks and I appreciate your help!

[JasonLion]

.2.567.49796..1.....5..9..68.9654.2.5.297..64..421.9.52...9........8..929..7.2...

One approach is to use an ALS-XZ.

[SteveG48]

You're heading for trouble. You have an incorrect elimination in r7c3.

[JC Van Hay]

Code: Select all

+---------------------+-----------------+------------------------+
| 13    2        138  | 5    6       7  | 138       4       9    |
| 7     9        6    | 348  3-4(2)  1  | 38(25)    38(5)   38   |
| 134   348      5    | 38   23      9  | 12378     1378    6    |
+---------------------+-----------------+------------------------+
| 8     137      9    | 6    5       4  | 137       2       137  |
| 5     13       2    | 9    7       38 | 138       6       4    |
| 36    367      4    | 2    1       38 | 9         378     5    |
+---------------------+-----------------+------------------------+
| 2     34568    1378 | 134  9       56 | 1345678   13578   1378 |
| 1346  3456     137  | 134  8       56 | 134567    9       2    |
| 9     38(456)  138  | 7    3(4)    2  | 138(456)  138(5)  138  |
+---------------------+-----------------+------------------------+


[HP(25)r2c57=5r2c8-5r9c8=HT(456)r9c257]-4r2c5=4r9c5
or
[2r2c5==5r2c8-5r9c8==4r9c5]-4r2c5=4r9c5

[Leren]

Here's the ALS move that Jason was referring to :

Code: Select all

*--------------------------------------------------------------------------------*
| 13      2       138      | 5       6       7        | 138     4       9        |
| 7       9       6        |a348     23-4    1        | 2358   a358    a38       |
| 134     348     5        | 38      23      9        | 12378   1378    6        |
|--------------------------+--------------------------+--------------------------|
| 8       137     9        | 6       5       4        | 137     2       137      |
| 5       13      2        | 9       7       38       | 138     6       4        |
| 36      367     4        | 2       1       38       | 9       378     5        |
|--------------------------+--------------------------+--------------------------|
| 2       34568   1378     | 13-4    9       56       | 1345678 13578   1378     |
| 1346    3456    137      | 13-4    8       56       | 134567  9       2        |
| 9       34568  b138      | 7      b34      2        | 134568 b1358   b138      |
*--------------------------------------------------------------------------------*

ALS XZ Rule: X = 5, Z = 4: (4=5) r2c489 - (5=4) r9c3589 => - 4 r2c5, r78c4.

After that the puzzle solves with a pointing pair of 1's in Column 1, a claiming triple of 3's in Column 3 Box 7, a naked triple 456 in Row 8 and singles from there.

r7c3 solves to 1, so you have made an error at some point leading to your diagram, as Steve pointed out.

Leren

[bananafish]

Thank you! Very much appreciate sharing the strategies and pointing out the problems! Looks like I have some Sudoku strategy studying to do.