The Single Possible Position technique is a beginner-friendly Sudoku method where one specific number can go in only one place within a row, column, or 3×3 block.
Instead of asking which number fits in one cell, this technique asks where a certain number can still go inside a house. If only one position is possible, that is where the number must be placed.
This is one of the most useful early Sudoku techniques because it helps you spot moves that are not obvious at first glance.
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Why Is the Single Possible Position Technique Important?
This technique is important because it teaches a different way of reading the puzzle.
With Last Possible Number, you focus on one cell. With Single Possible Position, you focus on one number inside a row, column, or block.
That shift is essential in Sudoku. It helps players see structure more clearly and unlocks progress when simple cell-by-cell scanning is no longer enough.
When Should You Use the Single Possible Position Technique?
You should use this technique when:
- a number is still missing from a row, column, or block
- several cells are open, but most are blocked
- only one cell can legally hold that number
This technique often appears in beginner and easy puzzles, but it stays useful at higher levels too.
How Does the Single Possible Position Technique Work?
Pick a row, column, or 3×3 block and choose one missing number.
Then test where that number could go:
- some cells are blocked by the row
- others are blocked by the column
- others are blocked by the block
If only one position remains possible, place the number there.
Example of Single Possible Position Logic
Imagine a 3×3 block is missing the number 5.
There are three empty cells in that block. One cell cannot take 5 because the same row already contains a 5. Another cell cannot take 5 because the same column already contains a 5.
That leaves only one valid cell in the block, so 5 must go there.
What Makes Single Possible Position Different From Last Possible Number?
Last Possible Number asks: what number fits in this cell?
Single Possible Position asks: where can this number go in this row, column, or block?
So they are close, but not the same. One starts from the cell, the other starts from the number.
This is why Single Possible Position is often called a hidden single. The number is not obvious from the cell alone, but it becomes clear when you study the house.
Is Single Possible Position Good for Beginner Sudoku?
Yes. It is one of the best techniques for moving beyond the absolute basics.
Many players improve quickly once they learn to look for hidden singles in rows, columns, and blocks. It is a simple technique, but extremely powerful.
FAQ
What is the Single Possible Position technique in Sudoku?
It is a Sudoku method where one number can only go in one place within a row, column, or 3×3 block.
Is Single Possible Position the same as a hidden single?
Yes. In most Sudoku terminology, this is the same idea as a hidden single.
Do you need notes for Single Possible Position?
Not always. In easy puzzles, you can often spot it visually. In harder puzzles, notes make it easier.
Why is this technique useful?
It helps you find moves that are not obvious from one cell alone and teaches you to think more strategically.
What should I learn after Single Possible Position?
After this, many players move on to candidate-based beginner techniques and early elimination strategies.
Final Thoughts
The Single Possible Position technique is one of the most valuable early Sudoku skills to learn. It helps you stop looking only at cells and start looking at the puzzle more intelligently. Once you understand it, your solving speed and confidence usually improve fast.
See the full Single Possible Position lesson in the Sudoku Academy.