Sudoku Hell

The ratings in this little gem suggest that the puzzles range from "difficult" through "very difficult" culminating with a collection of fiendish puzzles. True enough, but ... The trouble with this set of puzzles is that Nishio's solutions focus too often on a series of the simplest of the advanced skills - box, row and column claims; and hidden doubles, triples and quadruples. Even in the "fiendish" puzzles, the solutions only rarely venture into the use of such tools as conjugate pair chains, x-wings, swordfish, or xy-chains. And, in those few instances that these tools are required to squeeze out the solution, the entire back of the puzzle is typically broken by a single application of the more advanced technique. I confess that I haven't completed every solution in the book yet but I haven't found a single instance of a puzzle that required two really advanced techniques to reach a solution. That said, I'm happy to recommend this particular book to advanced Sudoku freaks who enjoy a challenge. Of particular interest is the small set of Sudoku variations included at the end of the book. In the context of this review, it would simply take too long to describe the rules of the variants that Nishio has created but, (trust me here) these are far more devious and challenging than the regular puzzles. Well done, Mr Nishio. I've still got more enjoyment to go in this book and I'd happily pick up any other puzzles books with your byline. Paul Weiss

These are very challenging puzzles. They can be lots of fun if you're willing to be patient and persistent.