Skyscraper

Skyscraper is a single-candidate pattern using two conjugate pairs. When two rows each have exactly two cells with a candidate, sharing one column but not the other, eliminations are possible from cells seeing both "roof" cells.

Technique

1. Find two rows where a candidate appears in exactly two cells each.
2. Two of the four cells must share the same column (the "base").
3. The other two cells (the "roof") must be in different columns.
4. Eliminate the candidate from cells that see both roof cells.

Tips

• Skyscrapers are easier to spot than X-Wings when columns don't align.
• The pattern resembles two buildings with different heights.
• One of the two roof cells must contain the candidate.