Sudoku: Linked Pairs and an XY-Wing Resolve a Stubborn Row

Sudoku XY-Wing logic breaks open this expert puzzle after the early singles, naked pairs, and locked candidates have taken us as far as they can. Follow the complete solve of Puzzle 12844 from Sudoku Extreme Techniques 99, Volume 1. The key moment is an XY-Wing built from candidates {2,4}, {1,2}, and {1,4}. It removes a 1, creates a single, and starts the finishing sequence. This puzzle appears on page 93 of the book, with its solution on page 212. Watch how each earlier deduction prepares the grid for the advanced technique—and how one precise elimination turns into a full solve. Which part of the XY-Wing was hardest to spot: the pivot, the two wings, or the elimination? Chapters 0:00 Puzzle setup and opening scan 6:44 Candidate notes and pattern search 8:09 How to spot Naked Pair 9:09 How to spot Locked Candidates 9:37 How to spot XY-Wing 15:55 Final solve and recap