Advanced Synthesis: Fish & Wing Mastery
The advanced tier introduced you to powerful pattern-based techniques: fish patterns that span rows and columns, coloring strategies, and wing techniques that chain bi-value cells. Review them all here before moving to expert-level chains and uniqueness arguments.
Techniques Covered
X-Wing
A 2x2 fish pattern eliminating a candidate from two rows or columns.
Finned X-Wing
An X-Wing with an extra candidate that limits but still allows eliminations.
Swordfish
A 3x3 fish pattern extending the X-Wing logic to three rows and columns.
Simple Coloring
Assigning two colors to a single candidate along conjugate chains.
Skyscraper
Two linked conjugate pairs that share a row or column for eliminations.
2-String Kite
A box-linked conjugate pair pattern combining a row and column chain.
Y-Wing (XY-Wing)
Three bi-value cells forming a chain that eliminates a shared candidate.
XYZ-Wing
A three-cell wing where the pivot holds all three candidates.
Remote Pairs
A chain of bi-value cells sharing the same two candidates.
Self-Assessment Checklist
These are the key pattern-recognition skills for advanced solving. Be honest about where you stand.
- ☐Can you spot an X-Wing by scanning two rows or columns?
- ☐Do you understand how a fin changes an X-Wing's eliminations?
- ☐Can you trace a Swordfish across three rows and three columns?
- ☐Can you color a candidate along a conjugate chain and find contradictions?
- ☐Can you identify Skyscrapers and 2-String Kites in a grid?
- ☐Can you set up a Y-Wing by finding the pivot and two pincers?
- ☐Do you know the difference between a Y-Wing and an XYZ-Wing?
- ☐Can you trace a Remote Pair chain and determine which cells see both ends?
What You Should Be Able To Do
Solve Hard-Rated Puzzles Confidently
Hard puzzles typically require at least one fish or wing technique. You should be able to work through them without resorting to trial and error.
Recognize Fish Patterns Across the Grid
You should have a systematic approach for scanning rows and columns for X-Wings and Swordfish, checking whether candidates align into the required rectangular or multi-line patterns.
Apply Wing Techniques for Difficult Eliminations
When subsets and fish are not enough, wings connect bi-value cells to make eliminations. You should be comfortable identifying pivots, pincers, and elimination zones.
Technique Recognition
Test your ability to identify which technique applies in a given situation. These exercises build the pattern-recognition skills that separate reading about techniques from actually using them.