Rules don't always work

Everything about Sudoku that doesn't fit in one of the other sections

Rules don't always work

Postby solgor100 » Sun Mar 30, 2008 4:40 pm

I am fairly new to Sudoku but have learned enough over the past few months to be able to solve most of the puzzles even through the expert category. I use Simplesudoku solver and find it a wonderful solving and learning tool. The thing that really frustrates me all the time is when I study up on a specific strategy and use it in solving, and the rules don't always work. They may work most of the time but not always, and as soon as I see the light come on at the bottom of the solver I consider the game lost and delete the puzzle. For example, yesterday I had a perfect X-wing formation in a puzzle according to the rules I learned, yet when I started deleting the proper numbers in the columns the error indicator appeared. This is just one example. Does anybody else have this problem? Any advice? I am really frustrated.
solgor100
 
Posts: 4
Joined: 16 March 2008

Postby hobiwan » Sun Mar 30, 2008 4:51 pm

I have never seen a valid X-Wing causing invalid eliminations (and I can't imagine how it could). It would be helpful if you could provide us with examples.
hobiwan
2012 Supporter
 
Posts: 321
Joined: 16 January 2008
Location: Klagenfurt

Postby ab » Sun Mar 30, 2008 7:55 pm

there are two reasons I can think of why you're having a problem when you make eliminations using an x-wing. One is that you made a mistake and it turned out there were 3 or more of the specific candidate on one or both of the lines. The other is that the puzzle that you were trying to solve doesn't have a solution. I guess there is a third possibility, that you haven't quite understood how to search for/apply the x-wing technique and you're making eliminations that don't follow from the x-wing.

As solgor100 said if you are applying any of the standard techniques to a valid sudoku puzzle, they will not cause invalid eliminations, period.
ab
 
Posts: 451
Joined: 06 September 2005

Postby wintder » Mon Mar 31, 2008 6:29 am

ab wrote:if you are applying any of the standard techniques to a valid sudoku puzzle, they will not cause invalid eliminations, period.


True.
wintder
 
Posts: 297
Joined: 24 April 2007

Re: Rules don't always work

Postby ronk » Mon Mar 31, 2008 9:59 am

solgor100 wrote:I had a perfect X-wing formation in a puzzle according to the rules I learned, yet when I started deleting the proper numbers in the columns the error indicator appeared. This is just one example. Does anybody else have this problem? Any advice? I am really frustrated.

Make sure that your "elimination cells" are the only cells highlighted. I've used Simple Sudoku for 2-years, and I still make that mistake occasionally.
ronk
2012 Supporter
 
Posts: 4764
Joined: 02 November 2005
Location: Southeastern USA

Postby Pat » Mon Mar 31, 2008 10:26 am

solgor100 wrote:The thing that really frustrates me all the time is
when I study up on a specific strategy and use it in solving,
and the rules don't always work.

They may work most of the time but not always,
and as soon as I see the light come on at the bottom of the solver
I consider the game lost.

For example,
yesterday I had a perfect X-wing formation in a puzzle
according to the rules I learned,
yet when I started deleting the proper numbers in the columns
the error indicator appeared.

This is just one example.

Does anybody else have this problem? Any advice? I am really frustrated.


hey solgor100,

what you gave is not an example
    next time you seem to have such a problem,
    please post the specific example
    so that we can offer you an intelligent response
User avatar
Pat
 
Posts: 4056
Joined: 18 July 2005

Postby ronk » Mon Mar 31, 2008 11:46 am

Pat wrote:please post the specific example
so that we can offer you an intelligent response[/list]

Are you implying our responses didn't show intelligence?:)
ronk
2012 Supporter
 
Posts: 4764
Joined: 02 November 2005
Location: Southeastern USA

Postby eleven » Mon Mar 31, 2008 12:01 pm

ronk wrote:Are you implying our responses didn't show intelligence?:)
At least they are very creative to say 2+2=4:)
eleven
 
Posts: 3094
Joined: 10 February 2008

Postby Pat » Mon Mar 31, 2008 1:34 pm

ronk wrote:Are you implying our responses didn't show intelligence?


i'm sorry if my post sounds that way,
the responses are obviously intelligent
    my poorly-phrased post
    was intended to get a reply from solgor100
User avatar
Pat
 
Posts: 4056
Joined: 18 July 2005


Return to General