Tag Archives: XY rail

A.D. Ardson’s Sudoku Diabolical


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

THLS Needs a Ride on the XY Railway


This post solves an XY-chain example to illustrate the simplicity and efficiency of XY-chains, as opposed to the rule based overcomplicated view of them in The Hidden Logic of Sudoku. From the first, this Sysudoku blog emphasized the fundamental nature … Continue reading

Posted in Advanced Solving, Berthier, Expert Reviews | Tagged , , , , | Leave a comment

The Nastiest Ever Party II


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

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

A Little More Extreme


Here is a follow up on the advanced level More Extreme 4, with background looks at the bv map, XYZ map, and X-panel . There is a challenge to find a forcing chain XYZ alongside a regular one. Entering the … Continue reading

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