Tag Archives: naked singles

Wayne Gould and Super Fiendish 4-57


This post reports two puzzles in the review of Brian Challenger’s Super Fiendish Sudoku, Sufi 47 and 57. Both are basic level, and in fact, half of the review puzzles are. For Sysudoku solvers, the term ‘fiendish’ is an overreach. … Continue reading

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Naked Singles in SudoRules


This post reveals how naked singles are produced, in Berthier’s rule hierarchy of increasing logical complexity,  by single rule that is a member of the set of rules for every resolution method. This explains why number scanning candidates, and maintaining … Continue reading

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