Decabit Software
XYZ-Wing

This technique is very similar to the XY-Wing technique. Find a cell with candidates XYZ that has two buddies, XZ and YZ. The candidate Z can be eliminated from the intersection of XYZ, XZ, and YZ.

Consider the sudoku below.

4
9
2
4
2
4
9

The cell r9c1 can take the role of XYZ, where X = 2 , Y = 9, and Z = 4. The cell r8c3 takes the role of XZ and the cell r3c1 takes the role of YZ. No matter what the value of XYZ is, one of the three cells must contain the digit 4. So we can remove the candidate 4 from the intersection of the three cells.

Note: The intersection of three cells is defined as the cells that share a unit with all three cells.
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Last Updated: 8/5/2017 12:27:29 PM CST