Blackwood in bridge

Blackwood, an essential convention

Blackwood is one of the most famous conventions in modern bridge. Easley Blackwood invented the ace-asking 4NT bid in 1933. The convention quickly established itself thanks to its simplicity and effectiveness, to the point of becoming one of the most widely played conventions in the world (along with Stayman).

Designed to check that the defence does not hold enough aces to defeat a slam in the trump suit, Blackwood has evolved over time: 30–41 Roman Blackwood, RKCB, Exclusion Blackwood, king ask, etc.

The principle of classic Blackwood

When the attacking side has found their trump suit, the bid of 4NT becomes an ace-asking bid. It is used to check how many aces your side holds in order to avoid the defence cashing two aces and defeating a small slam.

Classic responses to Blackwood 4NT

• 5: 0 aces
• 5: 1 ace
• 5: 2 aces
• 5: 3 aces

After the response, the player who has bid Blackwood usually concludes the bidding. We say that they "take the captaincy".

• If 2 aces are missing: you stop at the 5-level in the trump suit.
• If 2 aces are not missing: you can bid small slam at the 6-level.

Modern 30–41 Blackwood (Roman Blackwood)

Popularised by the Italian national team (the Blue Team) in the 1960s, this system changes the first two responses to make the sequence more economical.

30–41 responses

• 5: 3 or 0 aces
• 5: 4 or 1 ace
• 5: 2 aces
• 5: 2 aces + the trump king

The principle is simple: the player who bids Blackwood will distinguish 0/3 and 1/4 on the basis of the previous bids.

RKCB – Roman Key Card Blackwood

Since the 1980s, RKCB has become the standard, considering the trump king to be as important as an ace to play in slam: it is a key card.

Key cards: 4 aces + trump king = 5 key cards.

RKCB responses

• 5: 3 or 0 key cards
• 5: 4 or 1 key cards
• 5: 2 key cards
• 5: 2 key cards + the trump queen

RKCB allows you to deal more accurately with issues related to trump quality (trump king and queen).

Your turn: using Blackwood

Put the classic Blackwood convention into practice on a Funbridge deal.

Using Blackwood with a void

In principle, this is not recommended. Knowing how many aces your partner holds does not answer the real question because you do not know whether they have the "useless" ace in your void. You might occasionally resort to it if you know that your partner has no control in the suit.

Your turn: using Blackwood with a void

Learn how to handle Blackwood in situations where your hand contains a void.

Exclusion Blackwood

Exclusion Blackwood allows you to ask for the number of key cards excluding the ace in the suit where you are void.

It is shown by a jump control bid above the game level in the suit of the void.

Example:

1 – 3 – 5 with AKxxxx KQJxxx x / → "Partner, tell me your number of key cards other than the ace of ."

Responses (by levels)

• 1st available bid: 3 or 0 key cards (excluding the void suit)
• 2nd available bid: 4 or 1 key cards (excluding the void suit)
• 3rd available bid: 2 key cards (excluding the void suit)
• 4th available bid: 2 key cards + the trump queen (excluding the void suit)

After Blackwood: how to conclude?

After your partner’s response:

• If 1 key card is missing: you can stop with a small slam if everything else fits.
• If 2 key cards are missing: you must stop at the 5-level in the trump suit (if possible).
• If you hold 5 key cards: you can explore the grand slam if the trump quality and controls justify it.

Your turn: knowing when to stop

Practise interpreting Blackwood responses and concluding the bidding at the right level.

5NT: king ask

If the player who bid 4NT continues with 5NT, this is usually a king ask.

Message: "Partner, we have all the key cards (and often the trump queen). A grand slam is possible: show me your kings or sign off if you have extras."

Two common systems

1. Responses by number of kings (excluding the trump king):

6: 0 kings

6: 1 king

6: 2 kings

2. Responses by showing kings at the lowest level:

6: king of (if the trump suit is not )

6: king of but not king of , etc.

When 4NT is not Blackwood

Before using Blackwood, there must be a trump suit clearly set.

Otherwise, 4NT is often quantitative and invites to 6NT. Example with 1NT P 4NT

When your opponents make a high-level pre-empt, 4NT shows a wish to agree on a trump suit at the 5-level. Example: 4 4NT.

When your partner suggests a minor trump at the 4-level, 4NT is discouraging: it shows a misfit or a poor fit and a desire to play the contract of 4NT.

Technical precautions before using Blackwood

Before bidding 4NT, check:

• Is 4NT really Blackwood? (trump agreed without ambiguity)
• Do I have a genuine potential for 12 tricks?
• Is the trump suit reliable?
• Is a control missing in any suit?
• Does my partner know more than I do (should I let them bid Blackwood)?
• Could my partner’s response put me in a difficult position?

Conventions that revolve around Blackwood

1) Controls

Before Blackwood, it is recommended to check that you are not losing two immediate tricks in a suit (control bids).

2) Asking for the trump queen

The captain uses the first "useless" bid (often below 5 in the trump suit) to ask for the trump queen.

3) DOPI/ROPI

If the opponents overcall over Blackwood:

• Double or Redouble = 0 key cards
• Pass = 1 key card
• Higher bid = at least 2 key cards

4) 5NT Grand slam force

Jump to 5NT: asks partner to bid grand slam if they hold at least two top honours in trumps.

5) Asking bids

After a pre-emptive opening: a jump in a suit can ask for a specific control ("if you control this suit, we will play in slam").

Conclusion

Blackwood is an essential convention in modern bridge. It helps you avoid the dramatic scenario of bidding a slam with two aces missing. Like all major conventions, it has evolved over time. It requires a minimum of work (alone and with your partner) to avoid being used inappropriately.