Blackwood: asking for aces with 4NT
With Blackwood you bid 4NT to ask how many aces your partner holds, so you never bid a slam with two aces missing.
There are two kinds. Ordinary Blackwood asks for the four aces. Roman Key Card Blackwood (RKCB) asks for five key cards: the four aces and the king of trumps. RKCB comes in two orders, 3014 (also written 0314) and 1430. VosBridge starts English players on ordinary Blackwood; you can choose RKCB on your convention card.
The replies to 4NT
| Reply | Ordinary Blackwood | RKCB 3014 | RKCB 1430 |
|---|---|---|---|
| 5♣ | 0 or 4 aces | 0 or 3 key cards | 1 or 4 key cards |
| 5♦ | 1 ace | 1 or 4 key cards | 0 or 3 key cards |
| 5♥ | 2 aces | 2 key cards without the trump queen | 2 key cards without the trump queen |
| 5♠ | 3 aces | 2 key cards with the trump queen | 2 key cards with the trump queen |
When is 4NT Blackwood?
- When you have agreed a trump suit and have enough for a slam between you: about 33 points. That is when the bots ask.
- 4NT straight after partner's no-trump bid is not Blackwood. It invites 6NT: with a maximum partner bids 6NT.
- After the reply: with two aces missing, stop in five of your trump suit. With one missing, bid the small slam. With all the aces and about 37 points between you, bid the grand slam.
- Holding all the aces, 5NT asks for kings: 6♣ 0 or 4, 6♦ 1, 6♥ 2, 6♠ 3. With RKCB the trump king is not counted again.
Examples
Example 1: you ask
- ♠ A K 6
- ♥ K Q 9 4
- ♦ A K 8 5
- ♣ 7 2
Partner opened 1♥ and you have agreed hearts. With 19 points and a fit a slam is possible, so you bid 4NT (ordinary Blackwood). You hold two aces. If partner replies 5♦ (one ace), you have three between you: bid 6♥. If partner replies 5♣, that means no aces, since four is impossible. Two are missing: stop in 5♥.
Example 2: you reply
- ♠ K J 7 5 3
- ♥ A 8 4
- ♦ A 6 2
- ♣ 9 5
Spades are agreed and partner bids 4NT. You hold two aces and the king of trumps. Playing ordinary Blackwood you reply 5♥: two aces. Playing RKCB you have three key cards: 5♣ with 3014, 5♦ with 1430.
Common mistakes
- Bidding 4NT with no trump suit agreed, or straight after partner's no-trump. Then it is an invitation to 6NT, not Blackwood.
- Not agreeing which Blackwood you play. Look at your convention card together: ordinary, 3014 or 1430.
- Misreading 5♣. It means 0 or 4 aces; your own hand tells you which.
- Using Blackwood to find out about points. It counts aces, not points: first make sure you have enough for a slam.
See also: Counting points · Bridge scoring · Acol
Practise this soon
In VosBridge the bots ask and answer Blackwood as your convention card says. VosBridge is not open to everyone yet: a small group of testers already plays.
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