In this advanced Sudoku strategy tips tutorial post I’ll be doing another example of where you can use the advanced X wing method to help you solve very hard Sudoku puzzles. You can also visit my previous post for more X wing column variation tutorials with examples.
Following on from my previous post on advanced Sudoku tips and tricks, in which I introduced the X wing strategy. This post is an introduction to an even more difficult method. In fact it is one of the most complex Sudoku strategies, and that is the Swordfish technique. Please note, this is just an overview, for now of this technique. A more detailed tutorial will follow in due course, once I have outlined all the different Sudoku strategy methods.
In this post I’ll go over some simple Sudoku strategy tips based on the main Sudoku rules. Sudoku is a simple yet entertaining logic game which anyone with a bit of spare time can enjoy. Though they vary in difficulty, the basic rules of Sudoku are the same and are easy to pick up.
The Sudoku grid is made up of 9 3×3 boxes which are arranged to make a 9×9 grid. (See diagram 1).
Diagram1 - Sudoku Grid
The main Sudoku rules:
1. The numbers 1-9 must all appear in each row, column and 3×3 box of the 9×9 grid.
2. The numbers 1 to 9 can only appear once in each row, column and 3×3 box of the 9×9 grid.
3. There is only one solution to a Sudoku puzzle.
By applying these rules it is possible to deduce and eliminate squares where a number a. couldn’t appear or b. could appear based on whether that number is already in the column, row, or 3×3 box.
This is an overview of the basic principles of Sudoku, which are relevant whether you are doing easy or advanced puzzles. In the next few posts, I will be working through a variety of Sudoku puzzles with a step by step guide on how to solve Sudoku.