Tag Archives: unique rectangle

A funster Extreme 116 Labor Day Special


An effective bypass, and a simple uniqueness rectangle, and three choices to close down funster Extreme 116 early. Charles Timmerman’s funster Extreme collection is less than  extreme, but a good introduction to advanced solving methods. The basic work is easy, … Continue reading

Posted in Advanced Solving, Puzzle Reviews | Tagged , , , , , , , | Leave a comment

Another Look at Ardson Very Hard v.2 38


This post brings up an interesting question about the multiple solution puzzle: Does its ambiguity prevent strictly logical solving from reaching a solution? Introducing the first selected review puzzle of the A.D. Ardson Very Hard v.2 collection on April 11, … Continue reading

Posted in Advanced Solving | Tagged , , | 6 Comments

A Run Through Ardson’s Very Hard Volume 2


This post begins a review of A.D. Ardson’s Sudoku Very Hard Puzzles, volume 2. The review will cover 10 pre-selected puzzles from 400, every 40 starting with number 38. Well, almost. The puzzle at the end of the previous post … Continue reading

Posted in Puzzle Reviews | Tagged , , , , , , , | Leave a comment

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

THLS vs. Unique Rectangle


This post updates the UR chart, with credit to Denis Berthier, then debunks another unfortunate THLS pronouncement. The homework puzzle illustrates another penalty a human solver pays for interpreting  The Hidden Logic of Sudoku as solving advice. Now in our … Continue reading

Posted in Advanced Solving, Berthier, Expert Reviews | Tagged , , , , | 4 Comments

Suset Jelly in nrc Space


Here we work through an advanced supersymmetry example from The Hidden Logic of Sudoku, without the symmetries.  The humanly practical tools of Sysudoku are entirely adequate to the task. The theme of this review is that the burdensome emulation SudoRules, … Continue reading

Posted in Advanced Solving, Berthier, Expert Reviews, Sudoku Toolware | Tagged , , , , , , | Leave a comment

Longo’s Nastiest Ever Collection


This post begins the review of Frank Longo’s The Nastiest Sudoku Book Ever with a  review table and  solving highlights of two review puzzles, Nastiest 607 and 629. The original post was revised to correct errors found by my backup … Continue reading

Posted in Advanced Solving, Longo, Puzzle Reviews | Tagged , , , , , , | Leave a comment