Blackwood, the ace-asking convention, was developed early in the history of contract bridge as an aid to slam bidding. Despite its frequent misuse, it became a popular treatment because of its inherent simplicity. A bid of 4NT (in most constructive auctions) asks partner to reveal how many aces he holds using the following set of responses: 5♣ shows zero or four aces, 5♦ shows one, 5♥ shows two and 5♠ promises three. Easy. Even when used properly, however, there’s a problem that Blackwood fails to address, namely, the strength of the combined trump holding. Consider this situation:
|♠A 7 4||♠K Q|
|♥J 8 6 3||♥A 7 4 2|
|♦10||♦A K 8 5|
|♣A K J 6 2||♣Q 9 8|
Partner opens 1♣. You have an 18-count, but you decide to take it slowly by responding with a calm 1♦. Partner rebids 1♥.
Your hand is improving in value as the auction proceeds. If you are a Blackwood enthusiast, it wouldn’t be unreasonable to bid 4NT at this point. After partner’s 5♥ response (two aces), it would likewise be reasonable to bid 6♥. Your trump holding, however, will be a disappointment to partner. Barring the unlikely occurrence of the doubleton ♥K Q in a defender’s hand, declarer will lose two trump tricks.
This example is just one of many cases where not only is the number of aces held by the partnership a key to making a slam, but also the quality of the trumps.
Enter Roman Key Card Blackwood (RKCB). This approach is “Roman” because it’s a variation of an aceasking scheme developed by the Italian Blue Team. The phrase “Key Card” refers to the way in which this method improves on traditional Blackwood by counting the four aces and the king of the agreed trump suit as “key” cards — a total of five. Additionally, this method allows the partnership to check on the queen of the agreed suit.
Playing RKCB, the responses to the key-card asking bid of 4NT are:
5♣ zero or three keycards
5♦ one or four keycards
5♥ two or five keycards without the queen
5♠ two or five keycards with the queen
If the partnership is missing two (or more!) key cards, slam should be avoided. If the partnership is missing a key card and the queen of the agreed suit, slam is iffy unless the combined trump holding is 10 cards or longer.
On the example hand, therefore, partner would respond to your 4NT call with 5♥, showing two key cards, but without the ♥Q. You would then know that your side is missing either (1) a black ace and the ♥Q or (2) the ♥K and the ♥Q. Either way, slam would be a bad idea. You should pass 5♥.
What about situations where partner’s response is 5♣ or 5♦, but you still want to know about the queen of the agreed suit? In RKCB, the “asker” bids the cheapest suit after partner’s response to ask if he holds the queen. Responder says “no” by bidding five of the agreed suit.
(1) Limit raise.
(3) One or four key cards. Responder made only a limit raise, so it must be one.
(4) “Do you have the ♠Q?”
Responder says “yes” by bidding six of the agreed suit. In the above auction, therefore, responder could reply to the queen-asking bid of 5♥ with 6♠ if he held the ♠Q.
If responder has the trump queen and a side king, however, he can show both. (This can sometimes help the partnership bid a grand slam.)
(2) One key card.
(3) “Do you have the ♠Q?”
(4) “Yes, and I have the ♣K, too.”
(5) “Just what I needed!