Tag Archives: color trap

Berthier’s xyt-chains in THLS


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

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Paul Stephens’ Extremes Review


Here we review as one collection the “extreme” puzzles in Paul Stephens’  two current books, Mastering Sudoku Week by Week and The Sudoku Addict’s Workbook. In Stephens’ Weeks, puzzles for weeks 26 through 52 are labeled “Extreme”.  By this, Paul … Continue reading

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KrazyDad Super Coloring


This post follows the systematic dismantling of review puzzle SuperTough volume 5, book 8, #5, as it demonstrates the crushing logical power of Medusa coloring.  This completes the Sysudoku review of the excellent Super Tough collection found on http://krazydad.com. Here … Continue reading

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Coloring Sue de Coq and APE


Coloring is a general purpose weapon.  It limits the puzzle’s  ability to satisfy the restrictions imposed by  Sue de Coq and APE .  This explains why sysudokies  record the “almost” patterns found in the bv scan, and return to them … Continue reading

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Coloring Checkpoints


This post contains checkpoints for my sysudokie friends following the blog on Maestro 50 and Maestro 4 On the Maestro 50 coloring: In the first coloring, 8’s in E and SE and 9 in SE, are trapped.  They all see … Continue reading

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Color Wraps and Color Traps


A color wrap kills half the candidates in a cluster, and promotes the other half into clues.  If  you took up the challenge to color Maestro  40,  I’m  confident that you discovered the color wrap. That is a removal or … Continue reading

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