Naked Quad

A Naked Quad consists of four cells in a house that together contain exactly four candidates. These four digits must occupy these four cells, allowing elimination from other cells.

Technique

1. Find four cells in a house whose combined candidates total exactly four digits.
2. Each cell must contain only subsets of these four candidates.
3. Eliminate these four candidates from all other cells in the house.

Tips

• Naked Quads are uncommon but not as rare as Hidden Quads.
• Look for groups of cells with 2-4 candidates that only use four digits combined.
• Quads are harder to spot visually - use pencilmark highlighting if available.