Negative Double
Most commonly used by responder to show an unbid major with a hand not suitable to bid the major directly (too short or too weak).
Examples
| Opener | Overcall | Response | Meaning |
|---|---|---|---|
| 1♣ | 1♥ | Dbl | 6+ points, exactly 4♠s (1♠ would show 5+♠s) |
| 1♣ | 1♠ | Dbl | 6+ points, 4+♥s (note the + here - it can show 5♥s (and weak), as there is no room for a comparable bid to 1♠ shown above) |
| 1♣ | 1♦ | Dbl | 6+ points, exactly 4-4 in the majors |
| 1♦ | 2♣ | Dbl | 6+ points, at least one 4+ major (can’t have 5 card major and 10+ points) |
| 1♥ | 2♦ | Dbl | 4♠s and 6+ points OR 5+♠s and 6-9 points (denies heart support) |
| 1♥ | 1♠ | Dbl | 6+ points, at least 4-4 in the minors (denies heart support) |
Hearts Showing Negative Double

Note the double in this context shows 4+♥s
Minors Showing Negative Double

Misleading Negative Double

North’s double denies spade support
Robot Nuance

With 10 points and a 5 card major, I’d expect 2♠ rather than a negative double (perhaps the robot down-graded its weak 10 count)