Tag Archives: avoidable UR

Hodoku Unique Rectangles


This post lists the Hodoku UR techniques in a convenient reference sheet, and illustrates many of the examples in a more explicit Sysudoku format. I review Sysudoku principles for UR exploitation, and call attention to the Hodoku omission of forcing … Continue reading

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A Bv Scan of Week 48


Here we checkpoint the sysudoku bv scan on the blog homework puzzle, Week 48 in Paul Stephens’ Mastering Sudoku Week By Week.  The scan includes Sue de Coq and APE, two techniques ignored by Stephens’ books, and two techniques, XYZ-wings … Continue reading

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Beyond the Rectangle


The alternative deadly uniqueness formations of the Sudocue Guide are detailed in this post.  Also, there is a UR checkpoint on Sheldon’s Master Class # 3 that goes beyond the UR cases surveyed in recent posts. I can’t leave the … Continue reading

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Stuart’s Avoidable Rectangle


In The Logic of Sudoku, Andrew Stuart introduces a UR method in which corners on one side are known values, i.e. clues, and remaining candidates are prevented from forming a deadly rectangle with these clues.  This is his Avoidable Rectangle. … Continue reading

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