Monthly Archives: July 2017

Bean’s Extremely Hard I

Posted on July 25, 2017 by Sudent

A review of Rebecca Bean’s 600 Extremely Hard Sudoku Puzzles with Answers begins with the review table and two puzzles, 7-6 and 12-6. The collection is mostly basic, with the half of them solved by the slink marking bypass. Puzzle … Continue reading →

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

Dave Green’s Three Column Bypass 3-Fill

Posted on July 18, 2017 by Sudent

This post traces the bypass solution of Dave Green’s Friday **** of July 7, 2017, an amazing follow up to my recent addition of 3-fill’s to the slink marking bypass. This puzzle, starting with  three column 3-fills among the givens, … Continue reading →

Posted in Basic Solving Procedures, Green | Tagged , , | Leave a comment

Slink vs. Coloring Networks and Illogical Sudoku

Posted on July 11, 2017 by Sudent

This post reports a surprising fact about multiple solution puzzles, that solutions found by backtracking tree search can be logically inconsistent. Specifically, such solutions violate the coloring network implied by the givens. I happened on this fact by means of … Continue reading →

Posted in Advanced Solving | Tagged , , , , | 4 Comments

Closing Very Hard v.2 with the Real 38

Posted on July 4, 2017 by Sudent

To be fair, here is my do over of the real Ardv2 38, the one with a given 7 in r7c6.  My omission of it hatched a productive distraction, having no bearing on the collection it came from. The basic … Continue reading →

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