The Secret of Sudoku

Discover the x-wing sudoku technique, using two-row domains and column elimination to prune candidates, with examples from rows c and f and columns three and six.

Master the swordfish method in Sudoku by forming three chain rows (domain rows) and elimination columns, then eliminate candidates with X-wing logic and deformed fish cases.

Learn the jellyfish (four Cheyne Row) structure, extending the x-wing concept to four levels and eliminating candidates like seven and six from affected cells across related rows and columns.

Explore finned x-wing in sudoku, covering outer fin and two chain column structures, fish body and fish fin, and how to delete candidates from the overlapping area in a block.

Explore the finned grouped x cycles method to identify external fins in double and triple chain rows, ensuring fish body cells lie in block and deletions occur in overlapping region.

Explore the sashimi finned fish strategy in Sudoku, including the outer fin and the degenerated two chain column, and learn how deleting candidate six from the overlapping area aids solving.

Master the xy-wing technique in sudoku by analyzing three bi-valued cells with a pivot point, eliminating a candidate in common influencing region, and forcing placements such as nine or six.

Explore the xyz-wing technique in sudoku, understanding its three-cell structure, shared influence region, and how removing candidates and deducing numbers like one, eight, and nine leads to solving the puzzle.

Apply the w x y z wing technique to eliminate candidates in shared influence zones, and recognize pivot deficiency to solve Sudoku puzzles.

Explore the unique rectangles technique in sudoku by analyzing four-cell rectangles across boxes and rows to deduce a cell's value through elimination of candidates.

Demonstrate the hidden unique rectangle method by identifying a four-cell rectangle in two blocks, then remove candidate nine from the shared impact zone to uphold Sudoku’s uniqueness.

Learn the same side conjugate pair and the unique rectangle technique to eliminate a candidate and prevent multiple solutions in sudoku, such as removing three from C2 and E2.

Explore the extended rectangle in sudoku, expanding the unique rectangle to six cells across blocks and two columns, where C1 must be six and candidates 1, 3, 7 are shared.

Explore alternating inference chains, or nice loops, in Sudoku puzzles, using two-candidate interactions to form unique loops and uphold the unique-solution theorem.

Learn the avoidable rectangle technique to remove candidates and guarantee a Sudoku puzzle has a unique solution by using both given and entered numbers.

Apply the avoidable rectangle with candidate dependencies to remove a shared candidate from the rest of a row and its box, preserving the sudoku unique solution rule.

Learn the avoidable rectangle with explicit candidate dependencies in Sudoku, and how the rectangle allows removing seven and eight from box cells to preserve a unique solution.

Explore the avoidable rectangle with conjugate pairs in sudoku. Learn to eliminate candidates and ensure a unique solution through structured examples.

Master the almost locked sets technique by analyzing binary and ternary grids, identifying the true number that appears three times, and using it to deduce contradictions and solve Sudoku.

Explore the pseudocode method for sudoku deadlocks, using almost locked sets and trinary grids to remove candidate numbers in the joint impact region and reveal true numbers.

Apply the pseudo coq method to sudoku by eliminating candidates through two-cell interactions and ternary/dual value boxes, using column two, deadly patterns, and row deductions to reach contradictions.

Explore the aligned pair exclusion method in sudoku, using two cells with four candidates forming a conjugate pair in a row, column, or block to remove candidates.

Explore hidden pairs and almost locked sets in sudoku, learning how candidates are restricted to two cells in a block. Remove other candidates to narrow down the grid.

Explore hidden triples and almost locked sets (ALS) in Sudoku, learn how hidden triples form with cells, and apply eliminations through explicit and implicit triples across boxes, rows, and columns.

Explore merged almost locked sets with xy chains to reduce sudoku candidates by forming four-seven and three-nine pairs, enabling deletions in columns and blocks.

Explore the ins and outs method for sudoku by using arrays and pseudo arrays to track candidate numbers and eliminate options in overlapping row and block areas.

Learn to apply the finned fish technique in sudoku by identifying cross region arrays and eliminating candidates such as 2, 5, 7, and 9 from related rows and columns.

Explore almost locked sets and Z chains in Sudoku, identify strong relationships and weak links, form dual chains, and eliminate candidates using the alternative locked sets technique.

Explore alternating interference chains with almost locked sets, using pending arrays to form relationships across two way, three way, and multi way chains; eliminate candidates when ends must be true.

Explore almost locked sets (ALS) and ALS chains in sudoku, forming weak and strong relationships to eliminate candidates, and apply double strong chains to delete key candidates.

Demystify the bi-value universal grave in Sudoku by building strong and weak relationships, forming explicit by value graves and implicit by value graves, and removing candidates to reach elimination.