Tag Archives: iXYZ-wing

Super Fiendish Bookends 67 and 77

Posted on December 31, 2019 by

This post steps through the most fiendish of the 10 puzzles preselected for the review of Brian Challenger’s Super Fiendish Sudoku, SF 67. , and then adds one of the bypass victims, SF 77. Looking at the trace, you might … Continue reading →

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Reviewing James Forest’s Classic Sudoku

Posted on February 26, 2019 by

This post presents a Sysudoku solution of the Classic 24, from James Forest’s Book 30. We’ll do every 24th Classic. The first suggests an easy basic and an interesting diversity of advanced methods. The bypass fills the East boxes with … Continue reading →

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A funster Extreme 116 Labor Day Special

Posted on September 4, 2018 by

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 →

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Pattern Coloring Not-Both on Only Extreme 261

Posted on November 28, 2017 by

On this post of the Manuel Castillo Only Extreme review, Only Extreme 261 justifies its “extreme” label. After limited advanced moves, a pattern based coloring suggests an extension via a not-both trial on a long AIC strong link. The not-both … Continue reading →

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Almost Extreme 175 Tags Five Advanced Bases

Posted on October 31, 2017 by

This post reaches the halfway point in the review of Manuel Castillo’s Only Extreme collection, with Only Extreme 175. A double UR, a regular Sue de Coq and irregular XYZ-wing prepare the bv field for coloring, and an XY chain … Continue reading →

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No THLS Case for Hidden XY Chains

Posted on January 10, 2017 by

This post and the next demonstrate that the examples presented in The Hidden Logic of Sudoku as requiring “Hidden” XY Chains actually have alternative, and much less demanding, resolution paths in the Sysudoku repertoire.  The burdensome maintenance of symmetry grids is … Continue reading →

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Mike Peterson’s Very Hard Sudoku, v.1

Posted on September 6, 2016 by

Resuming posts after a quiet summer, this review identifies the title book as a basic level collection, offering an interesting challenge for the slink marking bypass, and little else.  The brief  introduction offers interesting historical facts, but is another example … Continue reading →

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The Nastiest Ever Party II

Posted on January 26, 2016 by

This post displays some sysudokie snapshots from Nastiest 618, 640 and 651, The bv scan rules, with line marked fish, unique rectangles, Sue de Coq, XYZ-wings, and XY-chains.  A  Sysudoku technique formerly rated extreme gets to stop for a drink. … Continue reading →

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Hodoku Grouped AIC II

Posted on November 24, 2015 by

This post continues with two more Hodoku examples, which illustrate how a human solver finds grouped AIC. As usual, Hobinger attributes them to making just the right premise at just the right place. In the Hodoku Grouped AIC section, the … Continue reading →

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