Blackwood is the most popular of the slam conventions. It is used to find out if there is enough Aces and Kings to bid a slam. A bid of 4 NT signals to your partner you are using Blackwood.

The Blackwood responder counts the number of Aces in their hand and responds according to the result:

5C : 0 or 4 aces.
5D : 1 ace.
5H : 2 aces.
5S : 3 aces.

A count of the Kings in partner's hand is requested with a subsequent bid of 5 NT. Your partner replies in a similar fashion at the 6 level:

5C : 0 or 4 kings.
5D : 1 king.
5H : 2 kings.
5S : 3 kings.

Caution: The 4 NT is considered to be Blackwood in various notrump sequences including direct raises and after Stayman. A bid of 4 NT over partner's opening 1 NT is not Blackwood, but a quantitative raise of the opening bid. In notrump situations the Gerber Convention is more appropriate.

Caution: Blackwood should only be used when the number of Aces is what you need to know. If you need to know if your partner has a specific Ace, use Ace-showing methods of slam bidding.



: AKQ62
: A7
: 62
: KQJ8

West North East South
- - - 1
Pass 1 Pass 2
Pass 4NT Pass 5
Pass 5NT Pass 6
Pass 7NT Pass Pass
Pass - - -

4NT: Blackwood. Aces?, 5: 2 Aces,
5NT: Ask for numbers of kings, 6: 2.

North needs only to know how many aces pd has to bid slam.


: T974
: K62
: AK93
: A3