Tag Archives: Berthier c-chains

Berthier’s xyt-Chains Rated Extreme


This post suggests a limited role for Denis Berthier’s xyt chain in human solving. I found no THLS examples of longer chains not requiring prior xyzt or hidden chains.The last prospect, Royle 17-33442 proves to be both unjustified and unnecessary. … Continue reading

Posted in Advanced Solving, Berthier, Extreme Solving | Tagged , , , , | 2 Comments

A Chicken Chok’in Checkpoint on Unhidden Chains


This post checkpoints Royle 17-16774, a rare example in The Hidden Logic of Sudoku of conjugacy chains dealing with a monster cloud of candidates. The checkpoint also catches SudoRules dismembering a “useless” XY nice loop that somehow sneaked into THLS. … Continue reading

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