The New Sudoku Players' Forum

[kartikarg]

[JasonLion]

Look for a unique rectangle type 1. More information on unique rectangles here.

After that it is singles to the end.

[nedBlake]

7 in (8,5) must be a solution. If not, then a simple X chain tells you that the 7 in (6,1) and (6,5) both would be solutions which can't happen.

[docjohn]

There's a skyscraper of 7's.
Look at the 7's in these squares:

r4c2 r4c6
r7c1 r7c6

so either r4c2 or r7c1 must be a 7

This will eliminate the 7's in r6c1 and r8c2