Book excerpt: Catch the latest wave in Sudoku-mania! These 275 X-Factor SuDoku puzzles are for the diagonally challenged, in 6 difficulty levels from Simple to Fiendish. X-Factor puzzles follow the same rules as for regular SuDoku puzzles PLUS the two shaded diagonal regions also contain the numbers 1 to 9 once only. Each X-Factor puzzle is joined to a previous and following puzzle through common puzzle solution numbers. As well, this book is an extension of "The World's Longest SuDoku Puzzle", now at 1,271 puzzles in length. Includes strategy guide for solving SuDoku puzzles, and tips on how to find X-Factor numbers. And for those who still can't get enough, try solving 275 riddles! Joe Defries is a current 2-time Guinness World Record holder, and is the joe in suJoku.com & joe-ks.com (the Largest Source of Internet Humour). Betcha Can't Beat That!* * re Joe's 'super-human puzzling feat' - the World's Longest SuDoku Marathon - as published in "The Addict's Guide to Everything Sudoku" by Fiorella Grossi, Fair Winds Press, 2007