John Welch writes an excellent blog for advanced Sudoku Solvers called Systematic Sudoku.
Every Tuesday he posts a new detailed analysis of a tough puzzle, one of his goals being to understand the comparative difficulties of various sudoku publications. Sudoku difficulty is hard to measure and describe, and different publications (including this website) use different metrics and language to describe puzzle difficulty. How do the “Super Tough” puzzles that I offer here compare to the “Diabolical” puzzles you might find in your local newspaper? John Welch aims to find out.
Today, I had the honor of seeing John review a puzzle from this website: Namely Super Tough Volume 5, Book 1, Puzzle 5. If you’re new to John’s website, you will probably find his notation system, reminiscent of algebraic chess notation, hard to understand. He explains the notation elsewhere on his blog. I suggest reading the introductory links he has posted at the top of his blog, as well as some of his earlier posts on easier puzzles, to help get a feel for his lingo.
Today’s review is the first of a series, and you’ll see a few follow up reviews of Krazydad puzzles in the coming weeks. I, for one, am looking forward to see what John has in store for the next few Tuesdays!
Link: Systematic Sudoku