Negative Double
The negative double (aka "Sputnik") is a conventional double used by responder after opener starts the bidding with one-of-a-suit and the next player makes a suit overcall. The double always promises 6+ points and, depending on the auction, at least four cards in at least one of the unbid suits. If one major suit is unbid, the negative double always shows that suit. If both majors are unbid, then the double shows both majors at the one-level. After an opposing 2-level overcall, the double only promises one major. A negative double usually shows 4 cards in the unbid suit(s), although it may also be made with a 5-card or longer suit in a hand too weak to bid it directly (see below). Note also that a negative double usually denies support if partner has bid a major.
Examples of negative double sequences:
| Opener | Overcaller | Responder |
1 | 1 | Dbl |
Usually shows 4-4 in the majors. With 5-4 or longer distribution, responder should bid his longest major first. With 5-5 distribution, responder should bid 1
, planning on rebidding his hearts.
| Opener | Overcaller | Responder |
| 1 | 2 | Dbl |
Shows at least one 4-card (or longer) major suit. Note that if responder has a 5-card (or longer) major, he must have fewer than 10 points. Otherwise, he should bid his 5-card major immediately.
| Opener | Overcaller | Responder |
1 | 2 | Dbl |
Shows 4 spades with 6+ points or 5+ spades with 6-9 points. Again, with 5+ spades and 10+ points, responder would bid 2S instead.
| Opener | Overcaller | Responder |
| 1 | 1 | Dbl |
Shows at least 4-4 in the minors.
Rebids by opener
With 4+ cards in partner's shown suit, opener can bid it at the cheapest level with a minimum hand. Lacking 4 cards, opener can do one of the following:
- Rebid a 5-card (preferably at least 6-card) suit.
- Bid notrumps with a stopper in the enemy suit.
- Bid a new suit naturally (a reverse still shows a strong hand).
- Cue-bid the enemy suit with a strong balanced hand that lacks a stopper in that suit.
- Bid partner's shown suit with only 3 cards (last resort).
Examples of opener's rebids:
| Opener | Overcaller | Responder | Opponent2 |
| 1 | 1 | Dbl | Pass |
| 1 |
Shows 3+ spades (usually 4) and 11-14 points.
| Opener | Overcaller | Responder | Opponent2 |
| 1 | 1 | Dbl | Pass |
| 2 |
Shows 4 spades and 15-17 points.
| Opener | Overcaller | Responder | Opponent2 |
| 1 | 1 | Dbl | Pass |
| 3 |
Shows 4 spades and 18-19 points.
| Opener | Overcaller | Responder | Opponent2 |
| 1 | 1 | Dbl | Pass |
| 4 |
Shows 4 spades and 20-21 points.
| Opener | Overcaller | Responder | Opponent2 |
| 1 | 1 | Dbl | Pass |
| 1NT |
Shows less than 4 hearts, a spade stopper, balanced or semi-balanced distribution, and 11-14 points (if playing a 15-17 1NT).
| Opener | Overcaller | Responder | Opponent2 |
| 1 | 1 | Dbl | Pass |
| 2NT |
Shows less than 4 hearts, a spade stopper, balanced or semi-balanced distribution, and 18-19 points (if playing a 15-17 1NT).
| Opener | Overcaller | Responder | Opponent2 |
| 1 | 1 | Dbl | Pass |
| 2 |
Shows 6+ clubs and 11-16 points.
| Opener | Overcaller | Responder | Opponent2 |
| 1 | 1 | Dbl | Pass |
| 3 |
Shows 6+ clubs and 17-19 points.
| Opener | Overcaller | Responder | Opponent2 |
| 1 | 1 | Dbl | Pass |
| 2 |
Strong and artificial. All cue-bids are a one-round force.
How high to play negative doubles is a matter of partnership agreement. If an opponent makes a 3 jump overcall, for example, is a double negative or penalty? Some popular limits for negative doubles are 2, 3 and 4; in other words, the opponents' interference could be no higher than those limits in order for a double by responder to be negative.