Mensa Guide to Solving Sudoku: Hundreds of Puzzles Plus Techniques to Help You Crack Them All

After solving many puzzles, I found 3 star and lower puzzles too easy, but I occasionally came across a 4 star puzzle that I could not solve without guessing. This book gives you multiple advanced solving strategies that should allow you to solve any "solvable" puzzle. I was disappointed to learn from the author of this book that some puzzles that indeed have one unique solution can only be solved by guessing. The 798 puzzles in this book, however, are guaranteed by the author to be solvable without guessing. So far, I have found this to be true. Hence, I have spent long hours on some of the puzzles with ultimate success without the fear that I am simply wasting my time. I agree with other reviewers that the grids are too small for the amount of note taking that is required to solve them, so I have been transcribing the puzzles onto larger photocopied grids. This strategy also saves the puzzles for another solver or for me at another time.

This book gets five stars because it is the first book I found that actually helped me get better at working hard puzzles (and I was no slouch before I got this). I see some reviewers complaining about the puzzles being smaller than many books, which is true, but this book has over 700 puzzles in it. I'll take more puzzles any day.

This wasn't the first sudoku book i bought, so i already new some techniques, but i bought it hoping this book could help me solve those difficult puzzles in which i was stuck. And it did, great book, explaines and repeats all techniques, most of them are easy to understand, others are preety long. All in all great book.

Peter Gordon's Sudoku solving techniques and Frank Longo's puzzles are a great combination. The book is a must read for anyone wanting to master Sudoku. Once you tire of the ordinary level Sudoku puzzles and want to solve the real tough ones, you will feel the need for this book. Prepare, however, to devote quality time, free of distractions, as the book needs to be studied carefully and understood and is not a fast read. The book also includes a huge number of puzzles of increasing difficulty which will keep you engaged for a long long time.

If you're looking to improve your Sudoku technique and are confused by the many books on the market, this is the one to get. Here's why: Strengths: It starts with the basics and clearly explains all the techniques you'll ever need, including some that are very advanced. Topics include scanning, elimination, subsets, and interaction (the basics, which will enable you to solve easy to intermediate puzzles); the x-wing family (including swordfish), which will enable you to solve difficult puzzles; and advanced techniques such as Gordonian logic and forcing chains, which will enable you to solve very difficult puzzles that you'll rarely encounter. Even if you can't follow some of the advanced techniques, you'll still learn enough to do most puzzles. The author also includes a website that solves Sudoku puzzles, which will tell you if a puzzle can be solved by logic or if you have to guess. The program uses X-wing and swordfish, but I don't think it includes every advanced technique, so it may guess in some situations where an expert would not. But it is very helpful, since it includes an option to suggest the next step rather than proceeding directly to the solution. Weaknesses: Yes, the grids are small. A simple solution is to copy each puzzle on a larger piece of paper, which will also preserve the binding. To me, the biggest weakness concerns the answers to the puzzles. The answers at the end of each chapter are okay, since you know that the puzzle deals with the contents of that chapter. But for the 700 or so puzzles at the end of the book, the author should have given the answers in stages, predicting where you're likely to get stuck and indicating what would help at that point (X-wing, swordfish, etc.). Of course, you can use the computer program to help you figure that out. In sum: Don't be put off by the weaknesses. If I were teaching a course in Sudoku (and I am a teacher), I'd make this the required text.