More than a century ago the great American puzzlemaker Sam Loyd listed four minimal criteria a puzzle must have in order to spark a craze: The invention must be "entirely new," its name must not bear the slightest resemblance to anything that has gone before, its object must be evident to the average person at a glance, and the thing must be so engaging that it "will make a person study over it until he is mad with himself."
By these criteria, sudoku has all the makings of a craze--which, in fact, it has become during the past year worldwide. The idea is so simple that it can be explained in a sentence. Nothing like it has ever been seen before. The very name "sudoku" (pronounced "soo-DOH-koo," and meaning, loosely, "single number" in Japanese) is exotic and appealing. And as nearly anyone who has tried sudoku will attest, the puzzle is utterly addictive. When you finish one, you immediately want to do more--better and faster. Moreover, you can spend weeks doing sudoku and not understand all the subtle solving strategies. Even for experts it remains mysterious and fascinating.
This book contains 300 sudoku puzzles carefully calibrated for difficulty and arranged in approximate order of difficulty, from very easy (#1) to brain-bustingly hard (#298). The last two (#299-#300) are giant 12 x 12 sudoku.
All the puzzles can be solved using certain, step-by-step logic. You never have to guess and hope the path you have chosen is correct.
The sudoku puzzles in this book were created by Peter Ritmeester and the staff of PZZL.com, an Internet-based company specializing in puzzles and games. Peter is the general secretary of the World Puzzle Federation and a onetime director of the annual World Puzzle Championship, which is devoted mainly to logical puzzles like sudoku.
Now, if you're ready, get out a sharpened pencil with an eraser (you'll need it), and have at it!
Copyright © 2006 by Will Shortz