Sudoku technique, as of yet unnamed. This puzzle felt like a study on this idea. Here's the puzzle:
The technique involves using knowledge that a number must be in one area to infer that it will not be in another. Consider the diagram below.
- The tan arrows show that the top right box must place a "1" in one of the two cells above 3 and 7.
- The green arrow shows that we can exclude "1" from being in any other cell of that row. This leaves us with "1" being in the bottom row of the top center box.
- The blue arrow shows where the lower "1" excludes that cell.
- We can place the "1" (shown in green).
If you play through this puzzle you will see this technique can be applied many times.
