Tag Archives: XY-wing

Wrapping Up Nakamoto Extreme With 183

Posted on April 28, 2020 by

This post completes the review of the Nakamoto Extreme collection. The review table follows the finish of Nakex 183. A Sudokuwiki assisted solution of Nakex 183 continues with the second APE triggered by the first’s removal of 8r2c9. In this one, … Continue reading →

Posted in Extreme Solving, Nakamoto, Puzzle Reviews | Tagged , , , , , , , , | Leave a comment

Brian Challenger’s Super Fiendish 7

Posted on December 3, 2019 by

The review of Challenger’s Super Fiendish collection opens with a long post, revisiting some advanced methods not seen here recently. Somewhat fiendish is the stonewalling in basic. The bypass gets nowhere, and the hidden triple alone removes candidates. Here is … Continue reading →

Posted in Advanced Solving | Tagged , , , , , | Leave a comment

Books 3 and 4 In the KD Insane Review

Posted on January 1, 2019 by

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 →

Posted in Advanced Solving, KrazyDad, Puzzle Reviews | Tagged , , , , , , , | Leave a comment

Funster Extreme 60 and 74 Go Together

Posted on August 14, 2018 by

Two brief advanced appearances are reported in this post in review of the Extreme section of Charles Timmerman’s Funster Hard to Extreme Sudoku. In Extreme 60, the bypass starts with a 3-fill and uses them to solve a big wedge. … Continue reading →

Posted in Basic Solving Procedures, Puzzle Reviews | Tagged , , , , , | Leave a comment

The World’s Most Over-Titled Sudoku Book

Posted on May 1, 2018 by

This post starts the review of World’s Hardest Sudoku Book, tracing Very Hard 25, the only one rated a 1.00. The review will cover the highest rated 10, taking the rating down to 0.90. The lowest of the 200 is … Continue reading →

Posted in Advanced Solving, Puzzle Reviews | Tagged , , , , , , , | Leave a comment

Decoding Hodoku Chain Notes

Posted on September 29, 2015 by

This post comments on the first part of the Hodoku “Chains and Loops” page. It reveals the premise dependent view of chains to be based on computer coding, and unsuited for human solving advice. It explains Hodoku’s chain notations as … Continue reading →

Posted in Expert Reviews, Hobiger | Tagged , , , , , | Leave a comment

Hodoku’s Limited XYZ Wings

Posted on September 22, 2015 by

In this post reviewing the Hodoku Wings page linked under Techniques, we see how an expert programmer can go wrong in explaining how to recognize where a technique applies and why it works . The omission of irregular wings is … Continue reading →

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

Wings and Chains With the Gordon Guide

Posted on January 13, 2015 by

This post reviews the Chapter 9 of Peter Gordon’s Sudoku Guide, entitled Forcing Chains and Grid Coloring. The guidance is very limited, and what there is, promotes guessing as opposed to solving by logic. This verdict is confirmed in the … Continue reading →

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

Bent Naked What?

Posted on July 8, 2014 by

Here I object to Bob Hanson’s use of the XY-wing and the XYZ-wing, in Sudoku Assistant – Solving Techniques, to introduce his more complicated concept of “bent naked subsets”. This treatment limits the wings to unit based links.  Also I’m … Continue reading →

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

The X-Panel and X-Chains

Posted on January 17, 2012 by

We will now be leaving methods relying on the bv map as the primary visual aid. With puzzles that survive these methods,   we need to remember that the bv map file remains an important resource.  With every clue or candidate … Continue reading →

Posted in Advanced Solving, Sudoku Toolware | Tagged , , , , , | Leave a comment