## Casual player, always stuck on Friday newspaper sudoku!

Advanced methods and approaches for solving Sudoku puzzles

### Casual player, always stuck on Friday newspaper sudoku!

Hey guys,

About two weeks ago, I first noticed sudoku in the Washinton Post, and have been hooked ever since! Since I've started, I've been able to beat Monday-Thursday puzzles in about 4-15 minutes, depending on the difficulty; however, I've never been able to beat Friday's puzzle !

I've read some of the pointers on the great sites some of you have published, but I guess I really don't understand some of the proprietary terminology that has sprung up in entheusiast groups like this, and was wondering if someone could give me some "plain English" pointers on this dastardly Friday puzzle!

Here's the original:
|**1|*5*|7**|
|25*|***|*86|
|***|3*6|***|
-----------------
|*7*|*3*|*4*|
|1**|8*4|**5|
|*4*|*7*|*1*|
-----------------
|***|4*5|***|
|49*|***|*67|
|**6|*1*|4**|

Here's with what little progress I've made so far

|**1|*58|7*4|
|25*|***|*86|
|***|3*6|5*1|
-----------------
|*7*|*3*|*4*|
|1**|8*4|*75|
|*4*|*7*|*1*|
-----------------
|*1*|465|***|
|495|283|167|
|**6|*1*|45*|

Thanks in advance for any pointers rendered!
dougthegreat

Posts: 2
Joined: 22 July 2005

There's only one candidate for the fourth cell across in the first row.
jafosei

Posts: 7
Joined: 14 May 2005

jafosei wrote:There's only one candidate for the fourth cell across in the first row.

Wow, that's great! You seemed to get that really quick, is there a specific method you subscribe to, or am I just an idiot?
dougthegreat

Posts: 2
Joined: 22 July 2005

When I'm playing with paper and pencil, I normally use dots to indicate which candidates have been eliminated from each cell (when I find the puzzle hard). Top left corner is 1, top center is 2, etc. until bottom right is 9. When I fill in a new number, I eliminate it from other cells in that box, row, and column by adding the appropriate dot.

In this case, though, I just plugged it into Angus' Simple Sudoku program. It automatically keeps track of the obvious remaining candidates for you, which eliminates having to manually fill in the dots.
jafosei

Posts: 7
Joined: 14 May 2005

Doug,

For me the key to your puzzle is that cols. 5 & 6 both conatin the numbers 5&6 (in your second version), which creates a naked 5-6 pair in box 5, and that gives you a 1 in row 4 and another one in row 2 and a 9 in row one, and from there it's pretty basic.
lkb

Posts: 1
Joined: 23 July 2005

jafosei wrote:There's only one candidate for the fourth cell across in the first row.

I see both 6 and 9 as possible candidates. What am I missing? (I'm brand new TODAY to Sudoku.) Thanks.

Posts: 2
Joined: 26 July 2005

There is already a 6 in box 2 at r3c6. Don't forget the rule of sudoku.
scrose

Posts: 322
Joined: 31 May 2005

scrose wrote:There is already a 6 in box 2 at r3c6. Don't forget the rule of sudoku.

Ooops! It's so obvious when it's pointed out.