Sudoku By SunSwallow

A sudoku that teaches as it helps. Every puzzle is rated by the hardest step it takes to solve, and every hint explains its reasoning in plain words. DIFFICULTY YOU CAN TRUST Most sudoku apps grade a puzzle by counting the numbers it starts with. That is why their "easy" can stop you cold while their "hard" falls in ten minutes. Here, each puzzle is solved step by step the way a person would solve it, then rated by the hardest step along the way: • Easy: only the simplest steps, the one number left for a square or the one square left for a number. • Medium: adds pointing pairs and box/line reduction. • Hard: adds pairs and triples. • Expert: adds the X-wing, the Y-wing and the swordfish. No puzzle, at any level, needs a guess. Each has exactly one solution, and logic alone reaches it. A HINT THAT SHOWS ITS WORKING Stuck? The first press of Hint tells you in plain words where to look and…