Sudoku Rules and Techniques

Sudoku Rules

Acknowledgements

I would like to acknowledge these sites referenced for strategy ideas and solving techniques.

SudokuWiki.Org by Andrew Stuart

PaulsPages.co.uk by Paul Stevens

Sudopedia.Org

Sudoku Rules

Cross Hatching

Counting

Naked Set

Hidden Set

Claiming

Remote Pairs

X Wing

XY Wing

Simple Coloring

Fishy Things

Unique Rectangle

X Chain

Aligned Pair Exclusion

Finned Fishy Things

Almost Locked Sets

Counting

Naked Set

Hidden Set

Claiming

Remote Pairs

X Wing

XY Wing

Simple Coloring

Fishy Things

Unique Rectangle

X Chain

Aligned Pair Exclusion

Finned Fishy Things

Almost Locked Sets

Acknowledgements

I would like to acknowledge these sites referenced for strategy ideas and solving techniques.

SudokuWiki.Org by Andrew Stuart

PaulsPages.co.uk by Paul Stevens

Sudopedia.Org

This same process can be applied to a given number in a given box that is contained in a single column.

The number 1 has to be placed in one of the blue cells in box 1 so it cannot be placed anywhere else in row 1.

Any instances of the number 1 in row 1 that are not in box 1 can be removed.

The number 4 has to be placed in one of the blue cells in box 7 so it cannot be placed anywhere else in column 3.

Any instances of the number 4 in column 3 that are not in box 7 can be removed.

If all possible candidate locations for a given number in a given row are contained in a single box, that row can be said to claim the given number. All candidate instances of the given number in the box that are not in the given row can be removed.

This same process can be applied to a given number is a given column that is contained in a single box.

The number 9 has to be placed in one of the blue cells in row 3 so it cannot be placed anywhere else in box 2.

Any instances of the number 9 in box 2 that are not in row 3 can be removed.

The number 7 has to be placed in one of the blue cells in column 5 so it cannot be placed anywhere else in box 2.

Any instances of the number 7 in box 2 that are not in column 5 can be removed.