Second-Degree Black Belt Sudoku®

Challenge your mind with the Second-Degree Black Belt Sudoku® by Frank Longo, an engaging puzzle book that elevates your Sudoku skills to the next level. Published in 2005, this 192-page book is perfect for those who have mastered the basics and are ready to tackle more complex challenges. The unique grading system, inspired by karate, categorizes puzzles by difficulty: start with the White Belt for easy puzzles, progress to Green Belt for medium, Brown Belt for hard, and finally confront the super-tough Black Belt challenges. Ideal for puzzle enthusiasts and anyone looking to sharpen their problem-solving skills, this book promises hours of stimulating entertainment. Dive into the world of Sudoku and see how far you can go!