Expert Sudoku — Extreme Difficulty

Expert grids rarely fall to singles alone. Master the XY-Wing technique — the wiki's guide walks the three-cell pivot pattern step by step.

Expert sudoku is the hardest of the standard difficulty tiers — the rung above Hard, and the point where casual scanning stops working. Each grid starts with only 19 to 21 given numbers, compared with 22 to 26 on Hard, so most of the board is blank and every placement has to be earned. Basic and intermediate moves alone won't get you to the finish. To crack an expert puzzle you'll lean on advanced techniques like X-Wing and Swordfish to eliminate candidates across rows and columns, plus chain-based logic such as XY-Wing when a single pivot cell links three others. Expect to spend anywhere from 40 minutes to over an hour on a tough grid.

Wondering where Expert sits among the very hardest tiers? Think of it as the top of the everyday ladder: Master comes next with just 18 or 19 givens and longer chains of inference, and Evil is the floor at 17 or 18 givens — the proven minimum for a uniquely solvable 9×9 puzzle. Expert is for solvers who have outgrown Hard and want a real fight without committing a full evening; if it starts to feel routine, the switcher above steps you up to Master and Evil. Every puzzle is verified solvable by pure logic — no guessing, ever — and if you get truly stuck, our advanced strategy guides walk through the exact techniques each one needs.