Tag Archives: XYZ-wing

A BARN Storming UHC 353 Finish


This posts finishes left page ultrahardcore 353, using several notable moves to expand a cluster.  Sudokuwiki starts it with a grouped terminal ANL with line and box winks, a regular swordfish expands the cluster, trapping four candidates. Expansion creates an … Continue reading

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Two Solvers Play With UHC 265


Heine’s left page ultrahardcore 265 is solved in two posts. This post follows the alternative methods of the review solvers Beeby and Sudokuwiki until they converge on a long series of AIC in the second post. Here is the grid … Continue reading

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Complex 1-ways Take Out KDI 475


This post updates KrazyDad Insane v.4, b.7, #5 with a bypass 4-fill and a solution free of trials, unless you consider the complex 1-way a trial. To the line marking, we add Beeby’s UR. If 6r1c7, the 9 slinks carry … Continue reading

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Nakamoto Extreme 123 Is, Briefly


Nakex 123 limps into AIC building briefly,  then succumbs to Sudokuwiki XY chains, simple coloring traps,  a coloring bridge and an outstanding BARN. Here is the grid at the end of a bypass exceptional among Nakamoto Extreme puzzles. The slink … Continue reading

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Sudokuwiki’s Nakamoto Extreme 103


After Sysudoku Basic, this post describes the Sudokuwiki advanced and AIC solution path on Nakex 103. The next post reports an alternative path shortened significantly by a freeform pattern analysis. Nakex 103 starts a little differently, with some bypass success: … Continue reading

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A Timely Finned Fish in funster Extreme 88


Continuing the review of Charles Timmerman’s funster Hard to Extreme Sudoku, with Extreme 88. The basic compensates for a modest  bypass with a favorable line marking. A naked single early and a finned 2-wing late. Finned fish is a topic … Continue reading

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Only Extreme 132 Is Cut From the Extreme Team


Another example of expansion of a limited coloring network via the not-both test on an AIC slink. It’s an extreme tactic that need only be tried as a last resort. While the expansion does work in OnEx 132, it is … Continue reading

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Only Not Extreme 46


The review of Castillo’s Only Extreme collection continues with Only Extreme 46.  A very extensive bypass is survived, to leave very little to add in box marking, and an interesting line marking.  The rest is murder by the usual suspects … Continue reading

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The Limited XYZ-wings of THLS


The XYZ-wing is limited in The Hidden Logic of Sudoku, as it generally is in Sudoku literature, by  a limited conception of the weak link.  This post presents a resolution of Royle 17-12407 using an iXYZ-wing, a form of the … Continue reading

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CLEF Homework on Unsolvable 190


Here is a checkpoint Sysudoku reader’s homework on the Sysudoku Cross Line Exocet Filter introduced in the previous post. Was it hard?  I stumbled many times on the 3467 case of the last week, and I may need corrections on … Continue reading

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