Tag Archives: almost nice loop

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. Here … Continue reading

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Only Extreme 390 – a Fitting Finale


In this post, the last preselected Sudoku of the review, Only Extreme 390, is solved by only advanced methods, but by an extremely thin margin.  The first crack in the armor is an irregular XYZ-wing. At first I missed an … Continue reading

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A Bridge Over Insane 485


Insane v.4 b.8 n.5, the eighth puzzle of a review of the KrazyDad Insane collection on http://www.krazydad.com,  had little left after Sysudoku basic solving.  XY chain ANL and a coloring bridge, supported by a cloud of bi-value cells, finishes it … Continue reading

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Stephens’ Extremes Snaps II


Here we continue with snapshots from the review puzzles from Stephens’ The Sudoku Addict’s Workbook.  The review covers 10 of 40 “Extreme” puzzles in this and Paul’s Mastering Sudoku Week by Week. The Extreme collection is highly recommended, even if … Continue reading

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Stephens Extremes Snapshots I


Here we have highlight snapshots from the review puzzles from Paul Stephens’ Extreme collection.  Recent posts have been about the Stephens approach to basic and advanced solving.  The Sysudoku solving of two of the review puzzles, Weeks 48 and Addicts … Continue reading

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To Nishio or Not to Nishio


This post examines Paul  Stephens’ favored form of Nishio, from his two current books on advanced Sudoku solving.  The analysis of the Addicts 140 determines the relationship between Stephens’Nishio and a simple test for grouped almost nice eliminating loops on … Continue reading

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Cell Forcing Chains


Here we examine forcing chains starting from all candidates in a cell.  When the number of chains is 2, there is nothing new.  Above that,  there is a new strategy to explore, which rivals LPO in complexity, but falls behind … Continue reading

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