Sudoku Snyder Notation
A Simple and Effective Way to Solve Sudoku Puzzles
Sudoku is a popular logic puzzle that challenges you to fill a 9x9 grid with numbers from 1 to 9, such that each row, column and 3x3 box contains each number exactly once. There are many ways to solve Sudoku puzzles, but one of the most common and useful methods is called Snyder Notation.What is Snyder Notation?
Snyder Notation is a technique for eliminating candidates and finding hidden pairs in Sudoku puzzles. It was invented by Thomas Snyder, who was born in 1980. He won the World Sudoku Championship three times and was also the World Puzzle Champion. The idea behind Snyder Notation is simple:You only write down the candidates for a number in a 3x3 box if there are exactly two possible cells for that number in that box.
You write the candidates in the corners of the cells, like this. This way, you can easily see which numbers are restricted to certain rows, columns or boxes, and use that information to eliminate other candidates or find hidden pairs.Snyder Notation Example 1
For example, in the image above, you can see that the number 2 can only go in two cells in the top-left box: R2C1 and R2C3. This means that the number 2 cannot go anywhere else in row 2 , so you can cross out any other candidates for 2 in those lines.More Examples of Snyder Notation
The Snyder Notation is excels in finding hidden pairs. A hidden pair is when two numbers can only go in two cells in a row, column or box, but those cells also have other candidates.Snyder Notation Example 2
In this example, we have Snyder Notation markings in the first box, first row, for the number 1. We also have Snyder Notation markings are in box 2, row 1, column 5, and row 3, column 6. You might notice that the notes from box 1 rule out the note in box 2, row 1. It tells us that the only available remaining cell to place 1 is row 3, column 6. Congratulations. With some practice, these cases are super handy to spot, and the Snyder Notation is fun to use.Snyder Notation Example 3
This is a fantastic and more advanced example of the Snyder Notation. You can determine that 1 & 2 must go in row 1 of box 1. The consequence is that the remaining 2 cells must be 5 and 9. All of these are marked with Snyder Notation. We can now spot that by looking at the notes for the number 5, row 2 is ruled out in box 2, and wonderfully, only one cell remains where number 5 can go, row 1, column 5. This example shows a bit of a thought chain, which is much harder to comprehend and follow without using the Notation. Your notes would clutter the entire board, and you would miss the forest for the trees!How to Use Snyder Notation?
To use Snyder Notation, you need to follow these steps:- Start with a Sudoku puzzle and scan the grid for any obvious numbers that you can fill in.
- For each number from 1 to 9, look at each 3x3 box and see if there are exactly two cells where that number can go. If so, write down the candidates in the opposite corners of those cells.
- Use the information from step 2 to eliminate other candidates or find hidden pairs in rows, columns or boxes.
- Repeat steps 2 and 3 until you either solve the puzzle or get stuck.
- If you get stuck, you may need to use more advanced techniques or guesswork to proceed.
Why Use Snyder Notation?
Snyder Notation is a simple and effective way to solve Sudoku puzzles because it:- Reduces the amount of writing and clutter on the grid
- Makes it easier to spot patterns and relationships among numbers
- Works well for most easy and medium puzzles
- Can be combined with other techniques for harder puzzles