Other Resources You May Find Of Interest A Google search on Sudoku currently calls up 51,000,000 sites (or so they claim; I only verified the existence of the first 600). This is vastly more than one could ever use. Two especially informative websites are those by Michael Mepham at Sudoku Online and Andrew Stuart at Scanraid Ltd. Few books on Sudoku go into strategies in any depth. Stuart's The Logic of Sudoku (Michael Mepham, 2007) is a wonderful exception. But his book and mine represent the two opposite poles of Sudoku-solving strategy. I regard many of his methods as superfluous, and I am sure that he regards most of my strategies as heretical. You need to have a close look at both.
The classical guide to Sudoku solving is that which Michael Mepham published in 2005, just as interest in Sudoku was building: Solving Sudoku. In a sense it is an ancestor of the book by Stuart. Mepham's forte is its clarity and simplicity.
Wayne Gould is the man who brought Sudoku from Japan to Great Britain in 2004 and introduced it through the London Times. He has an informative website, Wayne Gould Puzzles, which offers both a three-volume "Extreme Su Doku Gift Set" and a computer program that will generate endless new puzzles for you to solve. (Regrettably, the program does not work on a Mac.)
Will Shortz is the third giant of the Sudoku world, along with Mepham/Stuart and Gould. Shortz was the Crossword Puzzle editor at the New York Times for many years, but in 2004 broadened his base to include Sudokus. The New York Magazine has an interesting article about Shortz. He has produced a great number of Sudoku collections at all levels of difficulty. See Age of Puzzles or Amazon.
Other sites containing instructions on solving Sudokus can be found on the web, but they have two problems: (1) None of them is as clear and comprehensive as Andrew Stuart's book, and (2) None of them has anything to say about the strategies and approaches found in my book.
The analysis of how many different Sudoku puzzles exist can be found in an article, Unwed Numbers, by Brian Hayes, a mathematical columnist for American Scientist magazine. But note his later correction of the final number: How many Sudokus?
Two excellent pdf files are The Mathematics of Sudoku I and The Mathematics of Sudoku II. Jarvis and coworkers produced most of the calculations reported by Hayes.
Email questions or comments to support@sudoku-strategies.net Copyright ©2008 R. E. Dickerson