The New Sudoku Players' Forum

[Rainman127]

I can easily solve the Easy, Medium, and Hard puzzles, but the Expert puzzles are giving me a bit of an issue. I'm finding that I can clear most of the board, but then the remaining squares come down to a guess; there doesn't appear to be a definitive solution from what I can see and that is how this game should be! I'm posting a puzzle that I was recently working on and am curious if I'm just missing something that is overly obvious, perhaps a strategy? Thanks so much for the help, I do love working on these puzzles during my lunch break (though this one I was working on at 1am).

After looking at this puzzle again, it is clear that the middle block above the 1 has to be a 7 because the two potential 7 columns are the same for the top middle block and the bottom middle block, but other than that ... I just don't see how to proceed without guessing.


https://drive.google.com/file/d/0BxPjZrYj_AORdjQybWUzWTNBVGxDbm9mRHRpQU1XSU95QmRj/view?usp=sharing

[JasonLion-Admin]

I'm posting a puzzle that I was recently working on

No sign of a picture or text version of a puzzle. Difficult to comment without a puzzle for an example.

[Rainman127]

My post seemed to disappear. The IMG link doesn't appear to be working so I placed the direct link to my google drive. Thanks!

I can easily solve the Easy, Medium, and Hard puzzles, but the Expert puzzles are giving me a bit of an issue. I'm finding that I can clear most of the board, but then the remaining squares come down to a guess; there doesn't appear to be a definitive solution from what I can see and that is how this game should be! I'm posting a puzzle that I was recently working on and am curious if I'm just missing something that is overly obvious, perhaps a strategy? Thanks so much for the help, I do love working on these puzzles during my lunch break (though this one I was working on at 1am).

After looking at this puzzle again, it is clear that the middle block above the 1 has to be a 7 because the two potential 7 columns are the same for the top middle block and the bottom middle block, but other than that ... I just don't see how to proceed without guessing.


https://drive.google.com/file/d/0BxPjZrYj_AORdjQybWUzWTNBVGxDbm9mRHRpQU1XSU95QmRj/view?usp=sharing

[JasonLion-Admin]

You need to put the direct link inside URL tags for it to work correctly, which I did for you. I also merged your two topics.

EDIT: Fixed again.

Jason

[Rainman127]

Thanks!

[SpAce]

After looking at this puzzle again, it is clear that the middle block above the 1 has to be a 7 because the two potential 7 columns are the same for the top middle block and the bottom middle block

That's one way to see it. Another is to simply look at the middle column and see that it's the only candidate 7 there (i.e. it's a line-based hidden single). Your puzzle in text format after placing 7r4c5:

Code: Select all

.------------.-----------------.--------------.
| 7    9  1  | 2     3    6    | 45   8    45 |
| 3    5  4  | 79    8    79   | 6    2    1  |
| 2    6  8  | 1     45   45   | 7    3    9  |
:------------+-----------------+--------------:
| 8    2  59 | 459   7    3    | 459  1    6  |
| 6    4  3  | 8     1    59   | 2    59   7  |
| 59   1  7  | 6     459  2    | 8    459  3  |
:------------+-----------------+--------------:
| 459  8  6  | 459   459  1    | 3    7    2  |
| 1    3  59 | 4579  2    4579 | 459  6    8  |
| 459  7  2  | 3     6    8    | 1    459  45 |
'------------'-----------------'--------------'

That, however, was the only trivial move left.

but other than that ... I just don't see how to proceed without guessing.

If you want to solve this puzzle logically, you need to study some non-basic techniques. Probably the simplest path with the least number of different techniques requires one X-Wing and three W-Wings (+ basic pointing pair and claiming moves, and singles of course). You can study those here, for example:

X-Wing
W-Wing