How do I necessitate the use of the X-Wing pattern during Sudoku creation?

Question

I want to create a Sudoku puzzle, and I want it to be of moderate difficulty.

There's a specific pattern I want to include, called the X-Wing pattern:

This occurs when two numbers form locked pairs - the two squares are the only ones of a specific number in a row or column. As a result, the other in that row or column can be eliminated.

I want to create Sudoku puzzles which require the use of this pattern to be solved, partially because I want to practice it, but also partially because my friends and I like to swap difficult puzzles.

Currently, I use the "generate a random Sudoku and remove numbers" method to create new puzzles, then check in a solver to see whether it's valid and what patterns are used.

How do I go about modifying or creating a new generation process to ensure I will create puzzles with the X-Wing pattern?

Answer 1

I don't think you can force someone to use the X-Wing technique. There are several techniques to eliminate clues. If they eliminate the 7s in your example by a different technique , then the X-Wing will be gone.

Eliminating clues in a different order will also cause the grid to look different. This site has been around for years and may give some insight: http://www.setbb.com/sudoku/