Sudoku Help - Glossary

Here are some assorted terms and phrases used within the Sudoku Dragon help system.

Alternate pairs

For the hard, challenging puzzles you need to do some serious analysis. We have a full description for working with Advanced strategies and key to many a hard puzzle is the analysis of Alternate pairs. Alternate pairs make use of the linkage of pairs of possibilities in different groups. A pair is present when there are only two squares in a group where a possibility can go.

Annotation

You can add notes to any number of squares in the grid. This is useful for hard puzzles when you want to remember what options are available or have already been tried. Squares with annotations are indicated in the grid with a marker star in the bottom right corner. You edit the annotation using the Notes panel.

Automatic allocation

If you want to concentrate on just solving the harder squares you can use the automatic allocation facility to quickly mop up the easier squares. Just press the F12 key or the Automatic allocation toolbar button to solve 'easy' squares. One of the program options lets you choose whether to include 'Only choice' as well as 'Only square' solution strategies.

Forums

Our web site has a number of helpful forums where you can seek further help and advice in solving puzzles.

Hook strategy

For very challenging puzzles you may need to use the complex Hook or X-Y wing strategy to solve them.

Labyrinth

The trial and error method that is guaranteed to solve any Sudoku puzzle is sometimes called the Labyrinth. This is because the same sort of method can be used to get out of any old maze, you just try all the possible alternatives in turn. Most importantly you need to remember which choices were made and where.

Permutation

Sudoku is all about permutations, that is the order in which numbers are ordered in a puzzle. For all about permutations and the theory behind Sudoku please visit our web page.

Puzzle sizes

Sudoku Dragon provides a wide range of puzzle sizes and types from a tiny 4x4 puzzle up to a mighty 20x20. One of the beauties of Sudoku is that the rules are just the same. Commonly used sizes are the standard 9x9 and for more of a challenge 16x16.

Symmetry

The vast majority of Sudoku puzzles that you see are symmetric, that is the pattern of initial squares is deliberately made so that they look the same when the puzzle is rotated or viewed in a mirror.

Tentative possibilities

These are the marks you make to indicate where numbers can go in squares. A square can have multiple numbers. These are easily set by using CTRL+number key. There are also tentative impossibilities which indicate where you think a number cannot go - these can be set with CTRL+number key. All the settings can be seen and changed in the notes panel.

This page is part of the extensive help system for Sudoku Dragon 2. This information is for the version that is only available for download from Microsoft Store. For information on the legacy Sudoku Dragon please refer to the separate help system.