The New Sudoku Players' Forum

[dmashton]

I'm stuck at this point in this puzzle. Can some one help me shake loose and explain the technique to do so.
Thank you very much,
Dave
145,1457,8,2,1479,6,3,1459,59
3,147,1246,5,1479,47,1246,149,8
12456,9,1246,8,14,3,1246,7,56
9,6,7,1,8,2,5,3,4
8,2,5,3,47,47,9,6,1
14,14,3,6,5,9,7,8,2
16,8,9,4.3.5,16,2,7
7,45,26,9,26,1,8,45,3
12456,3,1246,7,26,8,146,1459,569

[bennys]

In row 2 for the candidats 1479 are locked for cells r2c2,r2c5,r2c6,r2c8
So you can eliminat them from r2c3 and r2c7

[simes]

Code: Select all

Row 2: hidden pair 26 in cells r2c3, r2c7 - removing other candidates for these cells
Column 3: naked pair 26 in cells r2c3, r8c3 - updating candidates for r3c3, r9c3
Row 3: naked pair 14 in cells r3c3, r3c5 - updating candidates for r3c1, r3c7
r9c7 = 4: only cell in column 7 that can contain 4

Read about naked pairs and hidden pairs.

S

[dmashton]

Bennys and simes,
Thanks for the insight. That was all I needed to finish it off. I can't believe I missed the hidden pair in row 2 since I can generally solve most puzzles in the newspaper and I have been looking at this one on and off for a few weeks. Now I can sleep peacefully again. I was especially interested in the relationship between the 4-numbers/4-squares application and the hidden pairs. Perhaps they will always occur together.
Thanks again,
Dave