## Carol Vorderman’s Super Difficults

This post considers Carol Vorderman’s “difficult” collection as a practice field for the Sysudoku bypass. Carol’s tips for solving are described, and sysudokie homework on the walkthough “difficult” example is checkpointed. The review of Master Sudoku is concluded with Vorderman solving tips and a report on the Master Sudoku “super difficult” collection.

Your homework assignment shows that Carol Vorderman’s “difficult” techniques carry you through on puzzles solved by the bypass, making the collection of 50 puzzles a nice challenge for your sysudokie bypass techniques, and your Wayne Gould attitude. My evidence for this is the following trace. I hope you got that far with the bypass, but if not, follow the trace for some instructive moments.

When I followed Carol’s walkthrough in Master Sudoku, her first pass 6 through 9 went as expected, with an “only one fits” on 8, and a “missing numbers” on 9. But from that point, moves came in no order I could identify.

The primary skill in the bypass is to react immediately to dublex, hidden dublex, “walls”, “squares”, and to clue and naked pair opportunities created by 3 free cells or less in units. With a blog trace as demanding as the above, I can expect to have to start over where I missed one.

The solver’s immediate reaction is not urged in Carol’s book, and rightly so. It is not important in basic solving to find and store away every bit of unused information. It is valuable for stretching the bypass as far as it can go. That is the appeal of the bypass for those favoring hard puzzles and advanced techniques.

As you might expect, Vorderman introduces pencil marks for handling “super-difficult” puzzles, her final collection in Master Sudoku. It’s one step beyond the “possibles” she marked with circles for particular numbers. On the first pass through the numbers, Carol adds the pencil mark to every “possible” cell. Her pencil marks are listed across the top of the cell. She does not anticipate naked pairs and triples as we do in the bypass, but finds them among the candidate lists. She covers naked singles (lone numbers) and hidden singles(single options), and naked triples, but does not mention other multiples, strong links or box/line restrictions.

If intending to stop there, where How to Do Sudoku did, Carol should not have allowed her book to be retitled Master Sudoku, or the cover to describe her as “the UK’s leading Sudoku expert”. She and her publisher know better. Her text should have at least alerted readers to advanced techniques beyond the scope of this book.

On the other hand, should you buy the book as a basic solving challenge beyond the bypass? Given that bypass workout, I had to determine if her “super difficult” collection would challenge Sysudoku slink marking and enhanced line marking techniques. With only 50 puzzles to review, I preselected five, 163 through 199 in steps of 9.

The results were disappointing. Two collapsed in the bypass, and one on the first number in boxmarking. One, #172 held out respectably in line marking. The last one tripped up on two box/lines. Carol neglected to mention this basic technique, but could reasonably expect her readers to recognize these in their options lists.

I appreciate Carol Vonderman’s effort to introduce Sudoku to a new audience. Master Sudoku, “Master” being an imperative verb, gives them the ability to handle the puzzles they see in most newspapers and magazines.

However, considering the availability of writings on advanced solving methods, Three Rivers Press of New York, being an imprint of Crown Publishing Group, a division of Random House, did not uphold the reputation of its parent company with their handling of this Sudoku book. It wasn’t necessary to misrepresent the level of Sudoku solving by the clever title change and cover. Let’s have some respect.

From here we leap to a second post on recent Andrew Stuart Unsolvables . It’s a very worthy illustration of the difference between logical trials and trial and error probes on a monster quality puzzle. To look ahead go to Andrew’s Weekly Unsolvables and look up the grid and comments on #183 of January 16, 2016.