Crane

Level 5 · Orange Belt

Strategy:

Single-Digit Patterns

Requires:

X-Wing

Overview

Crane uses two conjugate pairs of the same digit: one in a box and one in a line. The pairs connect through a shared cell, forming a pattern where one of the two tail cells must contain the digit.

How It Works

  1. Find a digit that forms a conjugate pair (exactly 2 occurrences) in a box.
  2. Find another conjugate pair for the same digit in a row or column.
  3. The pairs must share exactly one cell (the connection point).
  4. Eliminate the digit from cells that see both tail cells (the non-shared endpoints).

Example

Look for Crane.

1

Crane

Find a box and a line that each have exactly 2 cells with candidate 7.

2

Crane

Box 9 has a conjugate pair, and column 1 has a conjugate pair for digit 7.

3

Crane

These pairs are connected through row 7, forming a Crane pattern.

4

Crane

Either r8c7 or r8c1 must be 7. So these cells seeing both tails cannot keep 7: r8c4 and r8c5.

5

Crane

Remove 7 from the cells that see both r8c7 and r8c1: r8c4 and r8c5.

6

Result after applying the technique.

Tips & Patterns

  • Crane is closely related to Skyscraper and Two-String Kite - all three use two conjugate pairs connected through a shared unit.
  • The elimination targets cells that see both endpoints of the 'crane arms'.
  • Look for digits with exactly 2 occurrences in both a box and a line.