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# Solving Techniques 18 WXYZ Wing

In a pattern like the one below, the red Z can be removed as a candidate.

For an example, please look below. The [9] comes up in all cells. This [9] is the [Z].

If the lower left [19] cell is a [9], obviously a [9] can’t be entered in the other cells of this box.

If the lower left [19] cell is a [1], then a [9] has to be entered somewhere in the upper line, and it can’t be in the place indicated on the diagram.

The WXYZ Wing is a technique which uses a combination of four cells and four candidate numbers to eliminate candidates from other cells.

## WXYZ Wing 2

This pattern is also a WXYZ wing. “Which number?” You might ask. It is the [5]. Lets examine together.

If, in the diagram below, the [59] in the center box is a [5], the [5]’s from the same box and same line will be eliminated as candidates.

If, in the diagram below, the [59] in the center box is a [9], either one of the right hand box’s blue cells will become a 5.

Therefore, the X’s, which apply in both cases, can be eliminated as candidates.

## WXYZ Wing 3

This pattern is also an WXYZ wing. It is quite a distorted pattern. The [4] will be [Z]. Lets examine together.

If, in the diagram below, the left box’s [14] cell is a [4], then the [4]’s in the same row can be eliminated as candidates.

If, in the diagram below, the left box’s [14] cell is a [1], the blue cell in the right box will be a [4].

しTherefore, the X’s, which apply in both cases, can be eliminated as candidates.

## WXYZ Wing 4

Here we have a distorted pattern again. There are a variety of patterns, so it’s good to look for four cells and four numbers.

If, in the diagram below, the left box’s [29] cell is a [9], then the [9]’s in the same row can be eliminated as candidates.

If, in the diagram below, the left box’s [29] cell is a [2], then the [9] would be one of the two cells in the center box.

Therefore, the X’s, which apply in both cases, can be eliminated as candidates.

reference: sudokuwiki.org

## Names of cells in Sudoku

 A1 A2 A3 A4 A5 A6 A7 A8 A9 B1 B2 B3 B4 B5 B6 B7 B8 B9 C1 C2 C3 C4 C5 C6 C7 C8 C9 D1 D2 D3 D4 D5 D6 D7 D8 D9 E1 E2 E3 E4 E5 E6 E7 E8 E9 F1 F2 F3 F4 F5 F6 F7 F8 F9 G1 G2 G3 G4 G5 G6 G7 G8 G9 H1 H2 H3 H4 H5 H6 H7 H8 H9 I1 I2 I3 I4 I5 I6 I7 I8 I9