The New Sudoku Players' Forum

[kenngyk]

Please help......I use all the technique I knew but no hit....
Thank you so much!!

[svwluke]

Hi Kenny,

I'm new to this forum and I am not really familiar with the notation.

If you look at the last column, sixth row, the field with 7 and 9 as candidates: You have two cases here:

Case 1: That cell is a 7, than the cell in the same line (with 3/7) is a 3, then directly below that (3/6) is a 6. Line 7 column 8 (6/9) is a 9 then.
Case 2: The starting cell (with 7/9) is a 9.

In both cases you have a 9 either in the starting cell or in the end cell. There are two other cells that contain a 9 as a candidate and are adjacent two start cell and end cell: Line 6, column 8 (with 3/5/9 as candidates) and line 8, column 9 (with 2/9 as candidates). You can delete the 9 there as candidates since either start cell or ed cell are a 9. The 2/9 cell is a 2 then. From then on the rest of the sudoku is easy.

This strategy is called XY Chain.

I hope my explanation was understandable. English isn't my native language.