Blackout convention

The Blackout convention is used after a 1-over-1 response followed by opener's reverse bid at the 2-level.

Responder then rebids as follows:

A rebid of his own suit shows 5+cards in the suit and is forcing one-round, but does not promise any extra strength.

The cheapest bid of 4th-suit-forcing and 2NT shows exactly 4-cards in his own suit and a minimum hand for his 1-over-1.

The non-cheapest bid of 4th-suit-forcing and 2NT shows exactly 4-cards in his own suit, forcing to game but not suitable for any higher bid.

A preference back to the opening suit or raising the reverse-suit are both natural, game-forcing with mild slam-try or better.

"Examples:"

1Clubs - 1Spades - 2Diams -:2Hearts: "artifical:" exactly 4-cards Spades-suit, and minimum hand for 1Spades.:2Spades: 5+ Spades-suit, forcing one-round, but does not promise any extra strength.:2NT: "artificial:" exactly 4-cards Spades-suit and is game-forcing, but hand not suitable for any higher bid.:3Clubs: game-forcing with 3+ Clubs-support. At least mild slam-try.:3Diams: game-forcing with 4+ Diams-support. At least mild slam-try.:3Spades: game-forcing with 6+ Spades-suit.:3NT: natural with stopper in 4th suit.

1Diams - 1Spades - 2Hearts -:2Spades: 5+ Spades-suit, forcing one-round, but does not promise any extra strength.:2NT: "artificial:" exactly 4-cards Spades-suit, and minimum hand for 1Spades.:3Clubs: "artificial:" exactly 4-cards Spades-suit and is game-forcing, but hand not suitable for any higher bid.:3Diams: game-forcing with 3+ Diams-support. At least mild slam-try.:3Hearts: game-forcing with 4+ Hearts-support. At least mild slam-try.:3Spades: game-forcing with 6+ Spades-suit.:3NT: natural with stopper in 4th suit.

David Stevenson writes:

Note that while the principle is the same, many people play the detail as somewhat different. For example, all the people with whom I play Blackout use the following scheme:

1. After a reverse, the cheaper of fourth suit and 2NT is forcing, showing a relatively weak hand. Opener bids the next bid upwards unless he has game values.

2. If a rebid of responder's suit would be cheaper than fourth suit then it is non-forcing.

3. Other bids are natural and game forcing.

4. Responder's 3NT rebid after bidding the cheaper of fourth suit and 2NT is a mild non-forcing slam try in opener's first suit.