I have been solving Sudoku's and kenKen's from the newspaper, and from Sudoku monthly magazines for about 2 years. I love the mental exercise these puzzles provide. I can solve all beginner and intermediate puzzles without assistance. But the "tough", advanced, or "diabolical" send me to the Internet for assistance. I visited Mr. Zambon's web site, and founded somewhat helpful. But I would still prefer to solve based on my own acquired knowledge. That is why I bought the book. The book is very brief. Just a couple of dozen pages, including illustrations and taking the teaching from the beginning. The examples, explanations, and illustrations are based on a numbering system for rows and columns that begins at zero, so the rows go from 0 to 8, and so do the columns. But, let's remember that Sudoku itself uses digits beginning with ONE!. So, this discrepancy plays games with your head, and the understanding of the examples. It becomes frustrating to follow. After reading through the material multiple times, and following the examples with paper and pencil at the side, I still found I had not learned that much. But, maybe for a beginner, the book could be OK?