Sudoku Rules
Pointing Pairs
Master the "Pointing Pairs" technique, a powerful advanced Sudoku strategy. This guide teaches you how to find a candidate (e.g., '4') within a block that is confined to a single row or column, and then eliminate that candidate from all other cells in that same row/column outside the block.
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Pointing Triples
Master the "Pointing Triples" technique, an advanced Sudoku strategy. This guide teaches you how to find a candidate (e.g., '1') within a block that is confined to a single row or column, and then eliminate that candidate from all other cells in that same row/column outside the block.
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X-Wing
Master the "X-Wing" technique, a powerful advanced Sudoku strategy. This guide teaches you how to find a candidate (e.g., '4') that appears in exactly two cells in two parallel rows, and crucially, in the same two columns. This "rectangle" pattern allows you to eliminate that candidate from all other cells in those two columns.
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Y-Wing
Master the "Y-Wing" technique, an elegant advanced Sudoku strategy. This guide teaches you to find a "pivot" cell (AB) and two "pincer" cells (AC, BC), allowing you to eliminate the shared "victim" candidate (C) from any cell that sees both pincers.
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Swordfish
Master the "Swordfish" technique, a powerful advanced Sudoku strategy like X-Wing but using three rows. This guide teaches you how to find a candidate (e.g., '6') that appears only in the same three columns across these three rows, allowing you to eliminate that candidate from all other cells in those three columns.
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