Here I have to report a surprisingly poor showing, as an advanced solving collection, of Will Shortz’ “Beware! Very Challenging” puzzles from his 2008 book, Ferocious Sudoku.
Will Shortz collection books are by far the best known among U.S. Sudoku solvers. Though Sudoku is not his personal specialty, Will has probably done more than anyone else to popularize Sudoku in the United States. His books dominate the airport circular stands and bookstore shelves.
So naturally, the question arises: How tough are Will Shortz’ toughest? That would be the Beware series currently available in Ferocious Sudoku of 2008 and Trickiest Sudoku of 2011. The table below summarizes a review I’ve completed on the Ferocious Bewares. I preselected one of every 10, starting at puzzle 110, and ending on the last puzzle, number 200. If you have not pored through earlier review tables, the conventions are detailed in the Reviews page.
Compared to the review tables of Frank Longo’s Level 4, CrazyDad’s SuperTough, and Paul Stephens’ Extremes, this just doesn’t measure up. While travelling without a laptop, I enjoy Shortz’ Difficult collection in Ferocious and his Demanding collection from Trickiest. The Beware series offers a decent challenge for basic solving, but clearly, Will has to develop a tougher collection if he wishes to live up to his titles in advanced solving. These are lacking in ferocity and trickiness.
Only two of the ten review puzzles get to a full complement of candidates for advanced solving. Beware 160, your homework puzzle, is finished in box marking. If it didn’t for you, read through this trace.
When I first tangled with the Bewares, I must have been intimidated by the Shortz puzzle cred. On the first two I tried, Bewares 110 and 190, I couldn’t handle them, and I kept thinking I was going to get an insight into them as I went through advanced techniques for this blog. Then, when I was forced to consider the possibility that I might have made a mistake transcribing them to a template, I discovered that I had left out a crucial clue in each of them. Duh!
These corrections made, the review conclusion is that the Ferocioius “Beware! Very Challenging” collection is a challenge for basic solving skills, but falls short for advanced solving. Too much work for too little action. I’ll be confirming this unexpected conclusion with a similar review of theTrickiest Sudoku “Beware! Very Challenging” collection.
I can say that Shortz’ Beware puzzles give sysudokies a clear incentive to wring every clue possible out of basic solving. If you don’t, you are likely to be drowned in a sea of candidates, and will lack bv and slinks to make progress.
The first and only legitimate puzzle to breach the gap into advanced sysudoku solving was Beware 120.
Right out of line marking it contributes a worthwhile lesson. The bv map reveals a 259-wing and a 256 wing with hinges in the same box. Especially interesting is the effect each has on the other. Can you read the diagram and put it into words?
The example raises a general question: if two removing configurations are found on the same grid, but a removal by one destroys the second, does the removal caused by the second count? Of course, the answer is “yes”. The second removal was not contingent upon all of its candidates being true, and the removal of some of them does not change the fact that they established as candidates.
Have you read the diagram yet? Each of the 259-wing and 256-wing removes a 5-candidate from the other’s hinge cell, but each removal is already established before either removal is made.
Then a pleasant surprise: two interlaced XY ANL which work together to remove all extra 5-candidates from r7, creating three immediate clues. Beware 120 collapses immediately, with a 2-wing along the way.
Next we will explore Beware 190, to suggest ways to deal with multiple solution puzzle. In case you would like to preview the trail to this incredible result, here is Beware 190.