TABLE OF CONTENTS

INTRODUCTION ………………………………………….. 04
CHAPTER 1: HISTORY OF SUDOKU ………………… 06

CHAPTER 2: SUDOKU EXPLAINED …………………. 08
Variants ………………………………………………… 08
Japanese Variants ………………………………….. 10
Terminology and Rules ……………………………. 12

CHAPTER 3: THE MATH BEHIND SUDOKU ……….. 13
A Latin Square ………………………………………… 14
Unique Grids …………………………………………… 15

CHAPTER 4: CONSTRUCTION OF THE PUZZLE ….. 16
CHAPTER 5: SOLUTION METHODS–SCANNING ... 18
Cross-Hatching And Counting ……………………. 20

CHAPTER 6: BEGINNING THE CHALLENGE ………. 21
Guessing ………………………………………………… 23
Starting The Game …………………………………… 23

CHAPTER 7: CHANGE OF STRATEGY ………………… 28
Searching For The Lone Number ………………… 28
Twins …………………………………………………….. 30
Triplets …………………………………………………… 32

CHAPTER 8: ELIMINATE THE EXTRANEOUS ……… 34
Three Numbers Exclusively ………………………. 38
Step Up The Action …………………………………… 39

CHAPTER 9: WHEN EVERYTHING ELSE FAILS …... 41
Ariadne’s Thread ……………………………………… 42

CHAPTER 10: SOLVING A DIABOLICAL PUZZLE … 43

CHAPTER 11: SAMPLE SUDOKU PUZZLES …………. 47

CHAPTER 12: SOLUTIONS ……………………………… 53

CONCLUSION ………………………………………………. 58