Extreme Sudoku: Over 300 Super-Challenging Puzzles with Tips & Tricks

For those beginners looking for more challenging puzzles and lessons, for intermediates who want more helpful tips and some step-by-step guides for the solving of puzzles, and for those who are anxious to try "squiffy sudoku," sometimes called "samurai sudoku" by other writers; sudoku 16, with squares of sixteen, not nine, boxes; and "killer sudoku," complex puzzles with grids and no numbers printed in, this is the perfect place to start. The puzzles are printed on sturdy paper which survives erasures, and the boxes are large enough to accommodate many options. Vorderman's instructions are terrific--the clearest I've come across in any book I've found so far. She shows the whole puzzle so that the puzzler can see how a technique works relative to the whole puzzle, which many other writers do not do, and she takes the puzzler, step-by-step through two complete puzzles, showing WHY a number MUST go where it does. One of the examples she uses is puzzle #200, the most difficult one from her original Master Sudoku book. Unfortunately, those who are looking for truly "extreme" sudoku puzzles may be disappointed with this collection. None of the puzzles require advanced puzzle techniques, such as tracing unmatched pairs throughout a puzzle to fill in one number, and none even require something as basic as the "swordfish" to break through gridlocks. All of the puzzles in Vorderman's book can be solved by an intermediate puzzler who pays attention to the logic of the puzzles and fills in boxes by eliminating the obviously incorrect options. Note: A collection which some fans of more extreme sudoku may enjoy is The Sudoku Addict's Workbook: 150 Brand-New Puzzles with Gridlock-Busting Tips and Techniques by Paul Stephens. The last thirty puzzles in that book, labeled "extreme," are, for the most part, truly extreme, requiring advanced strategies not covered in Vorderman's book. Tom Sheldon's Sudoku Master Class is also very challenging. n Mary Whipple

Carol Vorderman seems to be an excellent sudoku editor, in the sense that the puzzles she presents are usually interesting and fairly fit the stated category. Still, this book is on the easy edge of "extreme." It is an excellent book for someone reaching out to more difficult and tricky puzzles than the common "easy, medium, hard" categories. Those looking for puzzles requiring single-number solving and multiple worksheets should pass it by.

If you have read Carol Vorderman's first book, MASTER SUDOKU, then you will be familiar with how she teaches. This volume picks up where the last one left off. What do you do when a puzzle is too hard and slicing and dicing just isn't getting you anywhere? Well, you could try the lessons in this book. These lessons take you to new levels of puzzles. Carol clearly shows techniques for solving the hardest of puzzles. She does so in a clear and easy to understand manner. Each lesson is then followed by sample puzzles for the reader to practice their new skills upon. But the book does not stop there. There is more to sudoku than just hard 9X9 grids. There are tougher variations and Carol takes the reader through some of the more popular variants and shows how to apply her techniques to them as well. You get squiffy puzzles where the 3X3 sub-grids have been replaced by other shapes. Sudoku 16 where the 9X9 grid has been replaced by a 16X16 grid. And then there is my favorite, killer sudoku, where the clues are given in the form of relationships between the answers. 300 puzzles are included in this volume to make anyone a true sudoku master.

Another 300 puzzles from Carol Vorderman. This volume throws in some increasingly difficult 9x9 standard sudoku puzzles, together with several variations. As with her Massive Sudoku, you get 16x16 puzzles (using numbers, not letters) as well as the jigsaw sudoku variation she calls "Squiffy." The big add here are several of the variation known as "Killer Sudoku," which require some minor math to solve (as with the new Kakuro puzzles, clues are given as sums and you must deduce the number pattern from the sum provided, still following the other traditional Sudoku rules.) Was that confusing? That, I suppose, is the value of the book - Vorderman provides solid instruction and very good solving tips for the new variations.