Category Archives: Advanced Solving

Techniques applying after candidates are identified. Why they work. How and when to look for them.

Only Extreme 218 Straight Up


Barely escaping the bypass, Manuel Castillo’s Only Extreme 218 gets tough, and brings out some seldom used methods. An alternative trial path by Single Alternative Sue de Coq, normally held in reserve,  follows in a second post. The bypass filled … Continue reading

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The Akron 2017 Championship Sudoku


This is another Sysudoku analysis of the championship puzzle of the Sudoku tournament put on by the Akron-Summit Public Library. It’s an annual tournament of four rounds, the last being a three person solve – off on poster board grids, … Continue reading

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Almost Extreme 175 Tags Five Advanced Bases


This post reaches the halfway point in the review of Manuel Castillo’s Only Extreme collection, with Only Extreme 175. A double UR, a regular Sue de Coq and irregular XYZ-wing prepare the bv field for coloring, and an XY chain … Continue reading

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Only Not Extreme 46


The review of Castillo’s Only Extreme collection continues with Only Extreme 46.  A very extensive bypass is survived, to leave very little to add in box marking, and an interesting line marking.  The rest is murder by the usual suspects … Continue reading

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Fick’s Advanced Path on Only Extreme 3


In the pre-review post of August 29, Cluster Extension by Not-Both Trials, a series of coloring cluster expansions were made by testing the not-both condition for AIC slink coloring. Like other trials, this tactic is considered extreme here in Sysudoku. … Continue reading

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A Surprising Dave Green Sunday 5-Star


My Sunday morning ritual Sudoku, the Dave Green 5-star of September 3, 2017,  sent me upstairs for PowerPoint support. This one breaks tradition by surviving Sysudoku basic, and with a heavy line marking. After no other advanced progress,  a four … Continue reading

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AIC Slinks Finish Only Extreme 3


This post continues the finishing coloring cluster expansion in Castillo’s Only Extreme 3, via not-both testing of AIC slinks.  After extending the blue/green cluster in the North bank via AIC slink, we continue with a second AIC slink adjoining the … Continue reading

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