Tag Archives: bi-value map

KrazyDad Super Tough Review


This is a sysudoku grading review of the Super Tough puzzles available on the KrazyDad website. KrazyDad is the creation of the very creative Jim Bumgardner.  It offers for download a huge number of free Sudoku  puzzles at levels ranging … Continue reading

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Absolutely Nasty 4 Review Snaps I


Here we link back to advanced solving posts as we enjoy sysudokie solving snapshots from the review table puzzles 0f Frank Longo’s Absoutely Nasty Level 4 (AN4) collection.  Did you ever get trapped looking at a neighbor’s vacation slides ?  You … Continue reading

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Snapshots from Sheldon’s Master Class


Here are some images from the Master Class review puzzles that illustrate Systematic Sudoku solving in action.  I deemed the collection strong in basic solving, with very limited excursions into advanced techniques. First is the #40 grid at the close … Continue reading

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Riding the XY Rails


This post illustrates the complete enumeration of all XY-chains and toxic end pairs by drawing curves through the bv along XY-chain routes. XY-chains are then systematically divided into sub-chains with toxic ends. It’s a Sysudoku innovation. The puzzle is from … Continue reading

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XY-Chains


This post explains the XY-chain, the most specific, easy to spot, and prolific of Alternating Inference Chains. It includes what many call the XY wing, as the shortest possible XY-chain. One XY-chain can generate multiple toxic candidate pairs. An XY-chain … Continue reading

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Regular XYZ-wings


This post explains how the regular XYZ-wing and WXYZ-wing make eliminations with toxic sets. Regular XYZ-wings are illustrated, and the XYZ form of the bv map is introduced. If you are following the Order of Battle, you should be returning … Continue reading

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