Author Archives: Sudent

About Sudent

My real name is John Welch. I'm a happily married, retired professor (computer engineering), timeshare traveling, marathon running father of 3 wonderful daughters and granddad to 7 fabulous grandchildren. The blog is about Sudoku solving. It covers how to start, basic solving to find candidates efficiently, and advanced solving methods in an efficient order of battle. It is about human solving methods, not computer solving.

The Especially Nice Loop of KD Insane 465


This post reports several features of an update of the post that introduced nice loop coloring. The illustrating nice loop was in itself remarkable. As shown already from books 1 through 5, KrazyDad’s hardest, the Insane collection, is hard enough … Continue reading

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The Insane 455 Pink/Olive Pattern Trial


This post reports on the updated KrazyDad Insane still at its posted date of August 20, 2013, but now updated to continue the introduction of pattern slicing, or pink/olive pattern analysis, by showing how it leads to decisive trials when … Continue reading

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Books 3 and 4 In the KD Insane Review


Welcome to 2019 Systematic Sudoku. This post continues on the updated KrazyDad v4 review, with KD Insane 435 and 445. This is a brief report on what you’ll find in the updated posts of August 2013. The review update begins … Continue reading

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KrazyDad Insane 425 Introduces Pattern Slicing


This post reports on the introduction of pattern slicing, a.k.a. the pink olive, in KD Insane v4, b2, n5 of 7/30/13. The method is defined, and demonstrated on the 3-panel of Insane 425. This review is being updated first, as … Continue reading

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The KD Insane 425 Boomerangs


This post reports on the introduction of spotting techniques for the boomerang ANL in the updated KrazyDad Insane v4 b2 n5. The cell based examples of this KD Insane review post of July 23, 2013 suggest the inclusion of both … Continue reading

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KD Insane 415 Updated


This post tells the story in the solving of Krazy Dad Insane v4, b1, n5, as reported in updated Sysudoku posts of 7/13/13 and 7/20/13. It’s one way that coloring and pattern analysis work together. Important features of Sysudoku Basic … Continue reading

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Beware 195 Ends a Basic Review


In this final post of the review of Will Shortz’ Hard Sudoku v.1, Beware! Very Challenging 195 is solved in the bypass. The review table is included for comparisons.  A new mode of blog posts will include reports and links … Continue reading

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