Roman Keycard Blackwood by David Bird

A: 4NT. There is no point in starting with a jump shift in diamonds. You are happy to make hearts trumps and can use RKCB to tell how high you should bid.

Your result so far:

A: 6♥. Partner's 5♥ response shows two keycards (which must be the two missing aces) without the ♥Q. You do not want to bid 7♥ when you are likely to be missing four trumps to the queen. Even if partner held six hearts, there might still be a trump loser. So, you sign off in 6♥.

If partner had responded 5♠ instead, you would have jumped to 7♥. (At matchpoints, you might well have bid 7NT instead, trusting that the diamonds would be good.)

Your result so far:

A: 4♣. Bidding 4NT would be premature, because you might be missing the top two diamonds. You should make the cue-bid (sometime called a control-bid nowadays) of 4♣, to show 1st- or 2nd-round club control.

If your partner continues with 4♦, showing the ace or king of diamonds, you can bid 4NT then. Suppose the cards lie like this, though:

____________________♠ K 10 7 4
____________________♥ A K 8
____________________♦ J 6 5
____________________♣ 6 4 3

♠ 9 2_____________________________♠ 8
♥ J 10 9 3 2_____________________♥ Q 7 6 5
♦ A K 9 4________________________♦ 10 7 3 2
♣ 10 8____________________________♣ J 9 7 2

____________________♠ A Q J 6 5 3
____________________♥ 4
____________________♦ Q 8
____________________♣ A K Q 5

Now North will continue with 4♥, showing a heart control but no diamond control. You can then stop in 4♠, knowing that you have two diamond losers off the top.

This is a typical deal where you need to use cue-bids. It is exactly why the Gerber convention has so little support among good players. They realize that cue-bidding is indispensable when investigating slams.

Your result so far:

A: 4NT. You have the playing strength for a slam, opposite a jump raise. Since you have controls in every side-suit, there is little to be gained by making a cue-bid in clubs. You can bid 4NT (RKCB) straight away.

On this occasion, partner responds 5♣, showing 3 or 0 keycards. In view of his bidding so far, it is clearly 3 keycards. So, you are missing one ace. Perhaps there is a trump loser too.

You would like to discover whether partner has the ♠Q. Roman Keycard Blackwood will allow you to do this! You can enquire about the trump queen, by making the cheapest non-trump bid (5♦ here). We will see what happens in the next problem.

Your result so far:

A: Pass. Yes, I realize that I did not give you the responses to the trump queen-ask bid, but you can guess that signing off at the five-level is the action that will deny the queen. Here, you know that an ace is missing too, so you will not risk bidding a slam.

What would partner do when he does hold the ♠Q? Various methods are available. These are the simplest.

(1) Basic. Bid a small slam with the queen, otherwise sign off.
(2) Tell partner how many side-suit kings you have. Two bidding steps would show one such king, three bidding steps would show two, bidding the small slam would show none.

This was the deal:

____________________♠ A 9 6 5
____________________♥ 4
____________________♦ A Q 8 2
____________________♣ A J 6 5

♠ Q J 2_________________________♠ 10 3
♥ J 10 9 5 3____________________♥ A 7 6
♦ 9 4_____________________________♦ 10 7 6 3
♣ 10 8 4_________________________♣ 9 7 3 2

____________________♠ K 8 7 4
____________________♥ K Q 8 2
____________________♦ K J 5
____________________♣ K Q

You will lose a heart and a trump, and be thankful to RKCB that you could know this in advance!

Your result so far: