The New Sudoku Players' Forum

[mjo1943]

Although i solved the fiendish example he gives i am unable to understand how his initial deduction of the 3's works.Surely col 2 as well as col 3 would be a safe 3 in row 9? Please put me out of my agony.

[Guest]

If you post the puzzle then I might be able to explain it...

[mjo1943]

If you post the puzzle then I might be able to explain it... :)

I tried to post it last week , but i did not get the hang of it.Lets try again!

Code: Select all

--8|-9-|--6
---|---|-2-
9--|5-3|1--

-1-|-78|6-5
---|---|---
6-5|14-|-8-

--1|6-7|--3
-2-|---|---
4--|-1-|5--

but my problem was not solving the puzzle , but understanding morrison's expalantaion of the 3 in box 7, ie c3r9...why not c2r9 ?

[Guest]

Hi mjo1943,

I'm not sure at which point you reach the choice between c2r9 and c3r9 (I havn't seen the explanation you refer to) but the following may help.

You should be able to establish that the only place a 3 can go in column 7 is c7r1 or c7r2.

Thus the only positions for a 3 in column 8 are c8r4 or c8r5.

Now consider row 6. The 3 cannot go in box 5 or box 6, so it must go in box 4. The only spare square in box 4 on row 6 is c2r6.

Thus the 3 in column 2 is already placed and so c2r9 is no longer a possibility.

Hope this helps.

[Guest]

Helped me Steve

I had played before, once.

Today I bought the book and have been obsesssed. Followed some of the logic threads on this site. I can go to sleep now feeling I have made some progress in my understanding of the problem: I need to switch between considering Columns, rows and cells as new facts emerge.

Thank you

[Guest]

got the three's explanation but not the two's explanation. Somebody pointed out you need to deduce the 9 in c6r9 first.

It's all very clever i have to say