From: tnh@sw.stratus.com (Tim Hill)
Newsgroups: rec.games.bridge
Subject: Re: What does the RKCB abbreviation mean?
Date: 16 Dec 92 16:53:58 GMT
Organization: Stratus Computer, Inc.
NNTP-Posting-Host: bigbootay.sw.stratus.com

In article <JKORPELA.92Dec16095219@lk-hp-17.hut.fi>, jkorpela@snakemail.hut.fi (Jukka Korpela) writes:
> In article <1992Dec14.151558.64@rcwusr> everettts@rcwusr.bp.com writes:
> 
>    - - RKCB is an acronym for "Roman Key Card Blackwood".  Sorry
>    but I lack the details on its use, other than the trump king counting as a
>    fifth ace.
> 
> Could someone please post a description of what can be regarded as
> "standard" RKCB?

Okay.  Since nobody else has taken the bait, I will.

I hereby declare the following to be Standard Roman Key Card Blackwood:

RKCB permits the 4NT bidder to learn about the top three trump honors as well
as side aces.

4NT is ordinary Blackwood when it's an opening bid or the first response
to a one-of-a-suit opening.

Any other unnatural 4NT bid is RKCB.  (When 4NT is natural is outside the
scope of this posting.)

RKCB requires agreement on the trump suit.  If there is ambiguity, then the
last suit bid before the 4NT call is treated as the trump suit for RKCB.
(This isn't the best agreement, but it is the simplest.)

Normal responses to 4NT:

     5C = 0 or 3 key cards
     5D = 1 or 4 key cards
     5H = 2 or 5 key cards, no trump queen
     5S = 2 or 5 key cards, trump queen

The five key cards are the four aces plus the trump king.  If you know there's
at least a 10-card trump fit, pretend you have the trump queen.

If in doubt as to whether partner holds the lower or higher number of key cards,
the 4NT bidder should sign off at the five level.  If partner does hold the
higher number, he should continue.

After a 5C or 5D response, the 4NT bidder may ask about the trump queen by
making the cheapest bid outside the trump suit (e.g., 1H-3H-4N-5C-5D or
1H-3H-4N-5D-5S).  Responses:

     no trump queen:                       cheapest bid in the trump suit
     trump queen, no side king:            5NT
     trump queen, at least one side king:  show the cheapest side king

For example in the auction 1H-3H-4N-5D-5S-6D, responder shows one key card, the
HQ, and the DK, and denies the CK.

If the 4NT bidder doesn't need to ask about the trump queen, he may bid 5NT to
ask for side kings.  This promises that the partnership has all five key cards.
Partner responds by showing his cheapest side king, without going past six of
the trump suit, or by bidding six of the trump suit.

If the 4NT bidder continues, either immediately or after asking about side kings
or the trump queen, by bidding a side suit, he asks partner to bid a grand with
second-round control of that suit.

If the responder to 4NT has a USEFUL void (i.e., not in partner's other suit):

     5NT                 = even number of key cards plus a useful void
     6 of a side suit    = odd number of key cards plus a void in the named suit
     6 of the trump suit = odd number of key cards plus a void in a suit above
                           the trump suit

Over interference, D0P1:

     double      = 0 or 3 key cards
     pass        = 1 or 4 key cards
     first step  = 2 or 5 key cards, no trump queen
     second step = 2 or 5 key cards, trump queen

(However, when a double might be mistaken as showing zero rather than three
key cards, bid the third step.)

Over high interference, DEPO.

I'm certain that everybody on the net will agree that this is The Standard ;-).
(However, if my total agreement with a pick-up partner were "RKCB", I wouldn't
be at all sure that we were on the same wavelength in any auction more
complicated than 1H-3H-4N-5H-6H.)

For a more thorough discussion (and more options), see Kearse. For a much more
thorough discussion (and many more options), see Kantar's new book on RKCB.
-- 
Tim Hill
Stratus Computer, Inc.                  tnh@vos.stratus.com
55 Fairbanks Boulevard                  508-460-2232
Marlborough, MA  01752                  fax 508-624-7488
Newsgroups: rec.games.bridge