Consider the following partial grid:

- Code: Select all

17* 935 *46

**6 47* 3*1

*34 16* 57*

6** 324 *17

4*3 716 **5

217 859 463

769 243 158

*** 681 7**

**1 597 6**

Looking at row one, we have a 2/8 pair at C3R1 and C7R1

Looking at the centre block, we have a 2/8 pair at C6R2 and C6R3.

Looking at row three, we have 8/9 at C1R3 the 2/8 pair at C6R3, and 2/9 at C9R3.

Ignore any other possible candidate reductions from the rest of the grid, and just look at the distribution of 2,8 & 9 in rows two and three.

We have a "right handed triangle" of 2's, and a "left handed triangle" of 8's, with the "common axis" of the triangle being a 2/8 pair, and the two other points of the triangle having a common third candidate (the 9). The pair on the common axis is the same pair as that currently unresolved in the remaining row.

Whichever way you try out the 2/8 pair in column 6, the top row is forced to the same solution.

Two questions I suppose.

1. Am I just describing an existing technique in a different way (remember I'm ignoring any other potential candidate reduction from the rest of the grid here)?

2. Would you consider this to be a "technique", or do you consider this as "guesswork"?