Peak Sudoku
Fish, wings, chains & uniquenessPeak Score 60–75

2-String Kite

One strong link on a row and one on a column, sharing a cell in the same box.

Also known as: Turbot Fish Type 2, Kite Pattern

Quick Summary

A 2-String Kite connects a conjugate pair in a row and a conjugate pair in a column whose inner ends share a 3×3 box. The outer ends force an elimination at their intersection.

Understanding the 2-String Kite Technique

The 2-String Kite is another elegant member of the Turbot Fish family. It uses two 'strings' of a single digit: one string in a row and one string in a column, each having exactly two candidate cells. One cell from the row and one cell from the column meet inside the same 3×3 box. Because that 3×3 box can hold that digit at most once, at least one of the outer 'kite tails' must be true, eliminating the digit from the cell where the two tails cross.

Visual Examples

Green cells highlight the 2-String Kite pattern, amber cells denote where candidates are affected, and struck-through pencil marks show the eliminations. Use the buttons or arrow keys to browse examples.

Example 1 of 5
Row 6 has 7 only at R6C1 and R6C7, and column 8 has 7 only at R4C8 and R7C8. R6C7 and R4C8 share the middle-right box, so only one of them is 7. That forces one of the far ends (R6C1 or R7C8) to be 7, so any cell that sees both ends can drop 7.
Removes: 7 from R7C1

How to Spot & Solve a 2-String Kite (Step-by-Step Guide)

The complete visual scanning and logical deduction process to execute this technique:

  • 1Find a row and a column that each have only two candidate positions for a target digit.
  • 2Check that one cell from the row and one cell from the column meet inside the same 3×3 box.
  • 3Because that box can only hold the digit once, those two inner cells cannot both be true.
  • 4Whichever inner cell is false forces the outer cell (the tail) of that line to be true.
  • 5Therefore, at least one of the two outer tails must contain the digit.
  • 6Eliminate the candidate from the cell where the row and column of the two tails intersect.

Common Traps & Mistakes to Avoid

  • The two inner cells must be in the same 3×3 box; if they are in different boxes, the constraint breaks.
  • The row and column must each have exactly two candidates for that digit.

Frequently Asked Questions

Why is it called a 2-String Kite?

Imagine the row as one string and the column as another string, tied together in the 3x3 box like the corner of a kite.

Expand your repertoire by learning prerequisites and advanced counterparts:

SkyscraperPeak Score 60–75

Two rows (or columns) where a digit has exactly two positions, sharing one column (or row).

Read guide →
X-WingPeak Score 55–70

A digit restricted to exactly two cells in two different rows, forming a rectangle.

Read guide →
Nice Loop (AIC)Peak Score 75–90

An alternating chain of strong and weak links – open or closed.

Read guide →

Ready to Practice 2-String Kite?

Try a puzzle in the Tough tier (Peak Score 61–70), or browse all 25 techniques.

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