- Blackwood convention
The Blackwood convention is a popular bidding convention in
contract bridgethat was developed by Easley Blackwood Sr.It is used to explore the partnership's possession of aces, kings and (in some cases) the queen of trumps, in order to judge more precisely whether a (ie making all, or all but one, tricks) is likely to be possible.
Two main styles of Blackwood exist - "standard" Blackwood, and a more sophisticated variant known as "Roman key card" Blackwood, named for the Italian team that developed it. Whilst the former allows inquiry about aces and kings in general, the latter allows precise inquiry about the key cards related to a particular agreed trump suit. In both cases, an initial bid of 4NT (No trumps) is commonly used as the conventional bid to ask partner about their high cards.
When this convention is in force, a bid of 4NT (No Trump) asks the partner to provide information on the number of aces in his or her hand (as long as the previous bid is not 1NT, 2NT, or 3NT). With no aces or four aces partner replies 5Clubs; with one ace, 5Diams; with two aces, 5Hearts; and with three aces, 5Spades. The asking bidder usually has one or two aces, so it is easy to discover the partnership's combined assets. A continuing bid of 5NT asks for kings with the replies following the same pattern. However, asking for kings tends to confirm that your partnership has all the aces and the responder may simply bid the slam at the seven level if he has an appropriate hand.
The responder should not count a void as an ace. Eddie Kantar recommends bidding the void suit at the 6 level with three aces and a void and 5NT with two aces and a void.
Although alternatives to the Blackwood convention exist (e.g. the Norman four notrump convention), virtually all bridge partnerships deploy a variant of the Blackwood convention (see below) as part of their slam investigation methods.
Roman Key Card Blackwood (RKCB)
In modern times, a system called Roman Key Card Blackwood (RKCB) has largely replaced the original system, at least among more advanced players. It originated from Roman Blackwood (see below). The king of trump is included as a control or a "key card"— in effect, as a "fifth ace"— and so more information is gained. The responses are basically the same as for Roman Blackwood, but with five "aces" in play, and additionally queen of trumps:
Kickback has the advantage that it saves bidding space and, especially for minor-suit fits, provides safe haven on level 5 if the required keycards are missing. Since the kickback bid takes up the normal cue bid, 4NT is usually substituted as the cue bid for that suit (e.g. 4NT is cue bid for hearts if diamond fit is discovered). The drawback is that in unpractised partnerships there can be a misunderstanding whether the bid on level 4 is Kickback, cuebid or suit preference:BridgeHandWE
K10642|A|AQ104|A53East intended 4Hearts as kickback, but West thought it was a secondary support for hearts, and decided to pass with minimal values. As result, a good grand slam in diamonds was missed.
An established partnership will have agreed that as hearts were not supported after opener's rebid, 4Hearts cannot possibly show support, and must be ace asking in diamonds.
Exclusion Blackwood or Voidwood
The Bridge World, May 1981 Volume 52, Number 8, by Ron Gerard] . was devised by Bobby Goldmanas an attempt to resolve the situation when the Blackwood-asker has a void. In that case, he is not interested in the partner's ace in the void suit, as he already has the first-round control; partner's ace would present a duplicated value in that case. It should be noted, however, that many players, even experts, refuse to play Exclusion Blackwood because of the potential disaster of forgetting the agreement.
It is usually played as the Roman Keycard Blackwood, with only four keycards: the three Aces outside the void suit and the King of trumps. However, the asking bid is not 4NT, but the void suit— Voidwood is made by jumping on level 4 or 5 in the void suit after a fit has been found, for example:Bids of 5Clubs, 5Diams and 5Hearts present a Voidwood, denoting the void in the suit bid and asking for other keycards. The responses are, as in RKCB:
*1st step – 0 or 3 key cards (1 or 4, if playing 1430)
*2nd step – 1 or 4 key cards (0 or 3)
*3rd step – 2 key cards without trump queen
*4th step – 2 key cards trump queen
The Blackwood convention is not without problems. When the Blackwood bidder has a void, he is not able to tell whether partner's ace is in the void suit (where it would not be of great help) or in a side suit (where it would be very useful.) For this reason
cue bidding to show aces is a superior method with hands that contain a void. In fact, most beginner-level players misuse this convention; they ask for aces when they really need other information from partner.
Beginners—and even more advanced players—often fail to comprehend the fundamental purpose of the Blackwood convention. They believe—incorrectly—that the convention is designed for the purpose of ascertaining if the partnership holds all four aces. In fact, the purpose of Blackwood is fundamentally to determine if the partnership is missing two or more aces. If the partnership is missing only one ace, then contracting for 12 tricks may still be reasonable, assuming that the partnership resources are sufficient to capture this many tricks.
Blackwood should not be used when the information gleaned will not answer the question that needs to be answered. A simplified, but instructive, way to think about Blackwood is this: "I am concerned that we may lose the first two tricks, if we bid a slam. I can use Blackwood as a kind of insurance policy, to guarantee that this will not happen." But Blackwood will not help if, due to the structure of the hands, there are multiple ways to lose the first two tricks. It only helps, for the most part, if the exclusive risk of losing the first two tricks is due to the opponents' holding two cashable aces. Obviously, the opposition might hold the ace and king of a side suit, and could bang those tricks right down, resulting in an immediate set.
Thus, a player should use Blackwood only when he can ascertain that the partnership holds at least second-round controls in all suits (kings or, if a suit fit is found, singletons). Thus, a Blackwood query by the player holding two quick losers in a side suit is a wild gamble, as it is still possible that the suit is not controlled by an Ace or a King.
For the same reason, it is generally wrong to use Blackwood with a void. (This is not always true, but the rule of thumb is: Don't use Blackwood with a void unless you are absolutely sure you know what you are doing, and why you are doing it. If you don't understand why it is correct, in a given case, to use Blackwood with a void, then it's very likely that its usage will be incorrect.) You may be missing two aces, but your void may compensate for the lack of one of the enemy aces. Thus, Blackwood will not tell you what you want to know: Are we at risk of losing the first two tricks? If your side has two aces and a void, then you are not at risk of losing the first two tricks, so long as (a) your void is useful (i.e. does not duplicate the function of an ace that your side holds) and (b) you are not vulnerable to the loss of the first two tricks in the fourth suit (because, for instance, one of the partnership hands holds a singleton in that suit or the protected king, giving your side second round control).
Other problems can easily occur when clubs is the agreed upon trump suit. The reply to Blackwood could take the partnership past their agreed suit and going to the next higher level may be one trick too high. The adage is 'don't use the convention if there is a possibility you won't like the reply.'
A further problem occurs when, after hearing his partner's response, the player who bid 4NT wants to stop in 5NT — as this is a forcing bid asking for Kings. The usual situation here is to bid a previously unbid suit instead (if there is one available) - your partner should recognise that this cannot be a genuine bid and corrects to 5NT.
Ron Klinger, collab Husband & Kambites. (1994) "Basic Bridge" Victor Gollancz, London, UK. ISBN 0-575-05690-8
Paul Mendelson, "Mendelson's Guide to The Bidding Battle" (1998) Colt Books, Cambridge, UK. ISBN 0-905899-86-5
* Ben Cohen and
Rhoda Barrow(ed). "The Bridge Players' Encyclopedia" 1967 Paul Hamlyn, London UK.
William S. Root, "The ABCs of Bridge" (1998) Crown Publishers Inc, New York, USA ISBN 0-609-80162-7
Eric Crowhurst& Andrew Kambites. "Understanding Acol. The Good Bidding Guide" 1992 Victor Gollanczin association with Peter Crawley, London, UK. ISBN 0-575-05253-8
* cite book
author = William S. Root and Richard Pavlicek
year = 1981
title = Modern Bridge Conventions
publisher = Crown Trade Paperbacks
* [http://www.bridgeguys.com/Conventions/RomanBlackwood.html Roman Blackwood]
* [http://www.bridgeguys.com/Conventions/BlueTeamRomanResponses.html Blue Team Roman Blackwood]
* [http://www.bridgeguys.com/Conventions/RomanKCB.html Roman Key Card Blackwood]
* [http://www.bridgeguys.com/Conventions/ExclusionKCBlackwood.html Exclusion Keycard Blackwood]
*PDFlink| [http://www.omahabridge.org/MHemPubs2/Kickback.pdf Kickback] |68.0 KiB
* [http://www.bruntonbridgeclub.org/ygreen_aces.htm Green Aces]
* [http://www.kantarbridge.com/tips_bid.htm Eddie Kantar's bidding tips]
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