## Solving Sudoku by Jerry Janusz

### Solving Sudoku by Jerry Janusz

Hello,

I have read a while ago (three months perhaps) a wonderful, powerful book on Sudoku written by the Emeritus Professor of Mathematics Jerry Janusz, entitled "Solving Sudoku. Illustrated Strategies", published by Trustworth Communications, LLC, 2016.
The book has 259 pages and around 120 pages on Sudoku techniques, including: elementary methods, subsets, empty rectangle, basic fishes, wings (XY-wings, XYZ-wings, WXYZ-wings, W-wings), chains, nice chains and nice loops, aligned exclusions, ALS-xz rule, uniqueness***, BUG. The first 27 pages cover elementary methods. The second part of solving techniques on advanced methods go from page 29 to 119.
Written by a mathematician, the description is very precise and (in my opinion) cristal clear. Most importantly, it was a real pleasure to read! First, a puzzle requiring only basic techniques is solved from start to finish. Several puzzles (to mention two of them: one Extreme 2026 in Hodoku standard setting, the second Extreme 2424) are solved from start to finish in the book. The second half of the book has 200 excellent* puzzles with a previous comment by the author on the difficulty levels and solving techniques needed****. When reading carefully the book, one realizes the author powerful skills in Sudoku**, because of the way you are guided during the resolution of difficult puzzles.
My only (very slight) criticism to the book is its conciseness. I understand that it is part of the author style of writing. The way the author describes each subject is very, very insightful (explanations by a master), but as soon as its done, its done!

Regards,
jco.

* in OTHER book I own, with good description of techniques, good practical advices on chains, the so-called diabolical last puzzle in the book was solved without pms! i.e., the author did not bother to add at least more challenging puzzles to allow the reader to use what is explained in the book. This is certainly NOT the case in J. Janusz's book. The puzzles ARE very challenging, requiring the excellent choice of techniques taught in the book.
** sad to say that many times this is NOT the case in many books written on Sudoku.
*** the author describes the basics and refer the reader to the Hodoku tutorial for more.
**** I did solve only a couple of them, because my main motivation to read Sudoku books is not in the proposed puzzles (see * above), although for THIS book I will solve more than just a couple.
[Edit: corrected part on the puzzles solved in the book]
JCO
jco

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Joined: 09 June 2020