Pocket Sudoku

A pocket sudoku book where Easy means easy: 120 puzzles sorted by a program into three levels by the hardest technique each one needs, one bold grid per 4 x 6 inch page.

This book is for an adult who does sudoku on a break, on a train or in bed, and for the daughter, son or partner who buys it as a small gift for a sudoku player. The goal is a puzzle at your own level, finished with a pencil and logic alone, without reaching for your phone. A level printed on a cover is only useful if it was measured, and a pocket grid is only useful if you can read it: this book does both. You solve one puzzle per page with a pencil, writing small candidates along the top of each cell, and check your answer at the back. It makes a small gift or a stocking stuffer for someone who already does sudoku, and it fits in a purse or a travel bag.

What's inside:

• 120 puzzles in three levels. 40 Easy (puzzles 1 to 40), 40 Medium (41 to 80) and 40 Hard (81 to 120), all classic 9 x 9 sudoku.
• Levels measured, not guessed. A program solved every puzzle by logic and placed it in the level of the hardest technique it needs. Easy needs only naked and hidden singles. Medium adds pointing, box/line reduction and pairs. Hard adds triples, the X-wing, the swordfish and the Y-wing.
• Fewer clues as you climb. 34 to 42 given digits in Easy, 28 to 34 in Medium, 26 to 30 in Hard.
• One solution each, and no guessing. A second program checked every puzzle: one solution, reached by logic alone, no grid printed twice, every printed solution matching its puzzle.
• A grid you can read at pocket size. One puzzle per page, the clues in bold 16-point digits, thick lines around the nine boxes, and room in each cell for pencil candidates.
• Answers you can find. All solutions sit at the back, two to a page, in puzzle number order. Under every grid, "Answer p." gives the page of its solution, so no answer faces a puzzle you are still working on.
• How to play, in plain words. Two short sections at the front: How to Play, and The Three Levels, which explains each technique in one line. Each level opens on a page of its own that says what it asks of you.
• The real size. A paperback of 4 x 6 inches, about the size of a postcard, 193 pages, black ink on white paper.

What it is not. It is not a large print book, it is not spiral-bound, and it has only classic 9 x 9 sudoku: no killer, jigsaw or other variants. The hardest technique inside is the Y-wing, so it is not for expert solvers looking for chains. The pages are printed on both sides: use a pencil, not a marker.

Put it in your bag, start at Puzzle 1, and keep a pencil with it.