Tag Archives: Sudoku UR

Remaining THLS XV hXY Avoided


Here we complete the report on the puzzles selected in The Hidden Logic of Sudoku to show that hidden XY chains are an “inescapable tool for the advanced player”, and therefore  require the generation and maintenance of symmetry grids. None … Continue reading

Posted in Advanced Solving, Berthier, Puzzle Reviews | Tagged , , , , , , | 2 Comments

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

Posted in Advanced Solving, Expert Reviews, Stuart | Tagged , , , , | 5 Comments