Tag Archives: color wrap

The World’s Most Over-Titled Sudoku Book

Posted on May 1, 2018 by

This post starts the review of World’s Hardest Sudoku Book, tracing Very Hard 25, the only one rated a 1.00. The review will cover the highest rated 10, taking the rating down to 0.90. The lowest of the 200 is … Continue reading →

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

A.D. Ardson’s Sudoku Diabolical

Posted on February 6, 2018 by

This post begins a brief review of A.D. Ardson’s Sudoku Diabolical, with a review table and analysis of the first of a pre-selected series 30, 70, . . . , 390. Ardson’s Sudoku Very Hard Puzzles, volume 2, very similar … Continue reading →

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

A Very Hard Finale with Ardv2 398

Posted on June 27, 2017 by

A hard basic leaves it to an unusual ALS to shake things loose, enabling an XY and a UR to wrap it up.  Maybe the hardest of the pre-selected Very Hard.   Line marking looks easy, until you look at … Continue reading →

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

More Satisfaction in Saturday 2

Posted on April 4, 2017 by

This post completes the last hour of the Satisfaction Sudoku tour of Sysudoku, with alternative solution paths beyond the bv scan in Saturday 2. It features a finned X-wing, a coloring wrap, and an alternative freeform pattern analysis with a … Continue reading →

Posted in Advanced Solving, Puzzle Reviews | Tagged , , , , , , , | 4 Comments

An xyt Color Wrap

Posted on February 14, 2017 by

In the spirit of Valentine’s Day, I come across a coloring resource in Berthier’s xyt chain. The elaboration of Royle 17-20565 in Chapter XVII of The Hidden Logic of Sudoku is a challenge in itself. By the theory of looking … Continue reading →

Posted in Advanced Solving, Berthier, Extreme Solving | Tagged , , , , , , , | 4 Comments

Berthier’s xyt-chains in THLS

Posted on February 7, 2017 by

Next we review the introduction of xyt-chains in The Hidden Logic of Sudoku. These are modified XY-chains which allow extra candidates in the chain cells, and unlike regular XY-chains, make eliminations regardless of whether the chain starting candidate is true … Continue reading →

Posted in Advanced Solving, Berthier, Extreme Solving | Tagged , , , , , , | 4 Comments

THLS Limps In On Chains

Posted on January 24, 2017 by

This post identifies the conjugacy chain, the last fundamental chain type to be introduced in The Hidden Logic of Sudoku, as a weakened X-chain.  Since the last few chapters introduce extensions for XY chains, it becomes clear that THLS is … Continue reading →

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