Sudoku strategies explained with graphics

Strategies


Overview Singles Naked Pairs Naked Triples Hidden Pairs Hidden Triples Naked Quads Hidden Quads Pointing Pair Pointing Triple Box Reduction X-Wing Finned X-Wing Sashimi Finned X-Wing Franken X-Wing Finned Mutant X-Wing Skyscraper Chute Remote Pairs Simple Coloring Y-Wing W-Wing Swordfish Finned Swordfish Sashimi Finned Swordfish Franken Swordfish Mutant Swordfish Finned Mutant Swordfish Sashimi Finned Mutant Swordfish Sue De Coq XYZ-Wing X-Cycle Bi-Value Universal Grave XY-Chain 3D Medusa Jellyfish Jellyfish Jellyfish Avoidable Rectangle Unique Rectangle Hidden Unique Rectangle WXYZ-Wing Firework Subset Exclusion Empty Rectangle Sue De Coq Extended SK Loop Exocet Almost Locked Sets Alternating Inference Chain Digit Forcing Chains Nishio Forcing Chains Cell Forcing Chains Unit Forcing Chains Almost Locked Sets Forcing Chain Death Blossom Pattern Overlay Bowman Bingo



❮ Previous Next ❯

W-Wing


If two Bi-Value Cells containing the same Candidates are connected by a Strong Links based on one of these Candidates, then the other common Candidate can not be the solution in any Cell that sees both Bi-Value Cells.


W-Wing

In the example above if candidate 3 is false in C8, then candidate 8 is true in C8, hence candidate 8 is false in B8, true in B5, false in G5 which implies that candidate 3 is the solution in G5 and thus false in G8.
Conversely, if candidate 3 is false in G5, a similar reasoning leads to candidate 3 being the solution in C8, which eliminates candidate 3 in G8.



You can practice this strategy by installing the SudokuCoach application on your Android™ device.

Get it on Google Play

❮ Previous Next ❯