Tag Archives: grouped ANL

Andrew’s Solver Tames Worlds 200


This post walks through the “very  hard” part of the solution path taken by  Andrew Stuart’s Solver through puzzle 200 of The World’s Hardest Sudoku Book by authors unknown. This is a remarkable turn of events for a blog devoted … Continue reading

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Bean Gets No Second Extreme


This post describes how I-41, in Extremely Hard v. 10 by Rebecca Bean comes close, but fails to force a deferred Single Alternate Sue de Coq trial. It does force a review of AIC hinges and grouped forcing chains. An update … Continue reading

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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

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