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Today's Dragon Tip

Word puzzles
Sudoku can be easily be adapted to work with letters rather than numbers. In our Word Sudoku puzzles there is a hidden nine letter word for you to find. If you work out the word then that can help you solve the puzzle.
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Possibility Explanation [Page 7 of 15])

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You will need to know which numbers can go in particular Sudoku squares. Many other Sudoku puzzle solvers do not give detailed explanations of what can go where and more importantly why.

Sudoku Dragon gives a clear explanation of why certain numbers are not possible according to the Sudoku rules. You select the 'depth' of analysis to determine which strategies will be made use of in making the analysis. As you increase the 'analysis depth' squares marked as 'looking possible' may be excluded to reflect subtler strategy rules. In the case illustrated only the numbers 1 and 4 are possible as all the other possibilities are excluded due to a conflict with a number in a row, column or region.

The more complex twin and shared subgroup exclusion rules can also be used in possibility explanations. Here the exclusion rules have knocked out the possibility of 6; 7 and 9 occurring in this square. The analysis has also spotted that 4 forms one of an alternate possibility pair.

The possibility panel is conveniently located just to the right of the main puzzle display.

Sudoku Possibility Explanation

sudokudragon You can download Sudoku Dragon for a free 23 day trial and investigate the possibility explanations for yourself. Go to our download page.

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