Straights - 200 Master Puzzles 9x9 (Volume 9)

About Book
This book introduces you to the amazing world of Straights puzzles. It will help you understand the rules of this puzzle. This book is perfect for players of all ages. You will find 200 exciting puzzles, for professionals. HOW TO PLAY
It is a 9x9 grid, partially divided by black cells into compartments. Each compartment, vertically or horizontally, must contain a straight - a set of consecutive numbers, but in any order (for example: 2-1-3-4).
The aim is to fill all white cells with the numbers from 1 to 9, same rule and goal as Sudoku.
No single number can repeat in any row or column.
Additional clues are set in some of the black cells - these numbers remove that digit as an option in the row and column. Such digits do not form part of any straight. As Straights belongs to the same class of puzzles as Sudoku the puzzle can demonstrate a wide spectrum of relative difficulty. The grade is determined by a combination of opportunities to solve at each stage and the difficulty of the strategy that grants each solution.