The New Sudoku Players' Forum

[Maria]

-3-/-6-/41-
--7/---/-3-
--1/-3-/--5
-------------
---/3--/8-1
39-/---/-2-
168/427/--3
-------------
-2-/583/17-
--3/--1/---
51-/-7-/389

[JasonLion]

Code: Select all

289   3     259   | 2789  6     2589  | 4     1     278 
24689 458   7     | 1289  1459  24589 | 269   3     268 
24689 48    1     | 2789  3     2489  | 2679  69    5   
------------------+-------------------+------------------
247   457   245   | 3     59    569   | 8     4569  1   
3     9     45    | 168   15    568   | 567   2     467 
1     6     8     | 4     2     7     | 59    59    3   
------------------+-------------------+------------------
469   2     469   | 5     8     3     | 1     7     46   
46789 478   3     | 269   49    1     | 256   456   246 
5     1     46    | 26    7     246   | 3     8     9   

.3..6.41...7....3...1.3...5...3..8.139.....2.168427..3.2.58317...3..1...51..7.389

There are a number of ways to make some progress from there. For example there are several locked candidates, and a hidden pair. However, I would go for the finned X-Wing on 4 in rows 5 & 7. Once you have done that, everything else should fall into place.

[Maria]

Got it, thanks - do you mind explaining me what a locked candidate and a hidden pair are and how they can be identified in this specific sudoku - sorry trying to improve

[JeJ]

So you know what a finned x-wing is but you don't know what a hidden pair or locked candidate is? That would be weird.

Anyway I am going to give you my definitions, but if you want more, you can always check http://www.sudopedia.org/wiki/Main_Page

Locked candidates: when the position of the candidates forces them to be at one specific house (row, colum or box) so they can't be in another. In your puzzle if you check the candidates for 9 in row 6, they are only on box 6 and not in box 4 or 5, this means that 9 in box 6 can only be in row 6 and you can eliminate the candidate in row 4, a similar situation occurs for the same candidate in row 8. A similar situation occurs for candidates 2, 5 and 6, but I am going to leave that unexplained to see if you understood the definition.

Regarding hidden pair, i assume you know what a naked pair is, a hidden one is when the two candidates are accompanied by other candidates, but they still comply with the condition that they are only in two cells of a house (again column, row or box). They are more difficult to spot of course.

[Maria]

Thank you I will check carefully, knowing about X-wing is because this is the only technique explained in the booking I have, I will come back if still difficult for me to get

[JeJ]

Thank you I will check carefully, knowing about X-wing is because this is the only technique explained in the booking I have, I will come back if still difficult for me to get

Just so you know, an X-wing is not the same as a finned X-wing. If you want to know the difference you can search http://www.sudopedia.org/wiki/Main_Page

[Maria]

I see I have a lot to learn.... would like to tell you that locked candidates and hidden pair are the techniques I use the most, the other just trying to learn, yr links are of much help but the best is to keep on using them at the right time.

[Maria]

do not wish to bother any one, I am stopped at another one

3../.8./75.
5.8/73./69.
..4/.2./138
--------------
.83/1.7/2.5
24./.5./81.
..5/8.2/3.9
------------------
.9./4../5.3
45./.1./9..
836/.../4.1
I wonder if I could have some help..........
Thanks

[JeJ]

EDIT

I hope you did not pay too much attention to my previous advice, because I didn't check well and it wasn't completely right.

What you need to find is:

Naked pair on column 9
Locked candidates (2) in column 3
Naked triple in box 2

[JeJ]

Also, when you post your puzzles, it would get you more help if you enclose your candidates using the CODE button

[PIsaacson]

Maria,

SSTS gets your puzzles quickly to the following PM grid, at which point Simple Sudoku can make no further progress.

Code: Select all

 *-----------------------------------------------------------*
 | 3     126   19    | 69    8     14    | 7     5     24    |
 | 5     12    8     | 7     3     14    | 6     9     24    |
 | 679   67    4     | 569   2     569   | 1     3     8     |
 |-------------------+-------------------+-------------------|
 | 69    8     3     | 1     69    7     | 2     4     5     |
 | 2     4     79    | 369   5     369   | 8     1     67    |
 | 167   167   5     | 8     4     2     | 3     67    9     |
 |-------------------+-------------------+-------------------|
 | 17    9     127   | 4     67    68    | 5     2678  3     |
 | 4     5     27    | 236   1     368   | 9     2678  67    |
 | 8     3     6     | 25    79    59    | 4     27    1     |
 *-----------------------------------------------------------*

A W-Wing at r8c3.<27> and r9c8.<27> with a stong link on 2 between col 3 and col 8 produces r8c89 <> 7, and that reduces the puzzle to singles from there on.

Cheers,
Paul

[eleven]

Code: Select all

 +-------+-------+-------+
 | 3 x . | . 8 x | 7 5 x |
 | 5 x 8 | 7 3 x | 6 9 x |
 | . .*4 | .*2 . | 1 3 8 |
 +-------+-------+-------+
 | . 8 3 |*1 . 7 | 2 . 5 |
 | 2 4 . | . 5 . | 8 1 . |
 | . . 5 | 8 . 2 | 3 . 9 |
 +-------+-------+-------+
 | . 9 . |*4 . . | 5 . 3 |
 | 4 5 . | . 1 . | 9 . . |
 | 8 3 6 | . . . | 4 . 1 |
 +-------+-------+-------+

There is a nice DP in the first 2 lines. To avoid 124 in the cells marked x, one of the 3 digits must be in r1c34.
Only possible are 12 in r1c3. So one of the digits must be there - and a 9 cant be there -> r5c3=9.

[daj95376]

.... would like to tell you that locked candidates and hidden pair are the techniques I use the most ...

Am I the only one who thinks Maria shouldn't be working on this puzzle in the first place?

If she's still trying to learn X-Wing, then many of the next steps offered for this puzzle are excessive to say the least.

What we should be doing is directing her to Simple Sudoku (or some other player/solver) that comes with a library of puzzles with known solution paths/techniques. Then, she can learn new techniques by working the library puzzles. At the very least, we should be directing her to Mike Barker's zoo puzzles.

http://angusj.com/sudoku/

post32822.html#p32822

[Maria]

.... would like to tell you that locked candidates and hidden pair are the techniques I use the most ...

Am I the only one who thinks Maria shouldn't be working on this puzzle in the first place?

If she's still trying to learn X-Wing, then many of the next steps offered for this puzzle are excessive to say the least.

What we should be doing is directing her to Simple Sudoku (or some other player/solver) that comes with a library of puzzles with known solution paths/techniques. Then, she can learn new techniques by working the library puzzles. At the very least, we should be directing her to Mike Barker's zoo puzzles.

http://angusj.com/sudoku/

post 32822

[Maria]

Code: Select all

 +-------+-------+-------+
 | 3 x . | . 8 x | 7 5 x |
 | 5 x 8 | 7 3 x | 6 9 x |
 | . .*4 | .*2 . | 1 3 8 |
 +-------+-------+-------+
 | . 8 3 |*1 . 7 | 2 . 5 |
 | 2 4 . | . 5 . | 8 1 . |
 | . . 5 | 8 . 2 | 3 . 9 |
 +-------+-------+-------+
 | . 9 . |*4 . . | 5 . 3 |
 | 4 5 . | . 1 . | 9 . . |
 | 8 3 6 | . . . | 4 . 1 |
 +-------+-------+-------+

There is a nice DP in the first 2 lines. To avoid 124 in the cells marked x, one of the 3 digits must be in r1c34.
Only possible are 12 in r1c3. So one of the digits must be there - and a 9 cant be there -> r5c3=9.

excellently presented, thanks!!!