Blackwood convention
Encyclopedia
In the partnership card game
contract bridge
, the Blackwood convention is a popular bidding convention that was developed by Easley Blackwood
. It is used to explore the partnership's possession of aces, kings and in some variants, the queen of trumps, to judge more precisely whether slam is likely to be a good contract.
Two versions of Blackwood are common: "standard" Blackwood, developed by Easley, and "Roman key card" or "RKC" Blackwood, named for the Italian team which invented it. Standard Blackwood enables one partner to count partnership aces and kings in general. Key card variants are defined by a particular "key" suit and enable counting the trump king and queen, as well as aces and kings. Both versions are initiated by a bid of four notrump (4NT), and the entire family of conventions may be called Blackwood 4NT in both versions, or Key Card 4NT in the key card variation.
There are other 4NT conventions, such as Norman four notrump
, San Francisco
and Byzantine Blackwood
, but almost all bridge partnerships employ some member of the Blackwood family as part of their slam-investigation methods.
If the partnership's preceding call is a natural bid in notrump, then 4NT is also natural. Over an opposing pass it is simply a raise and a quantitative invitation to six notrump, a small slam. Over a four of a suit it is likely to be a competitive raise, expecting to play four notrump. Those natural interpretations may hold in other auctions where the partnership has previously bid notrump naturally or shown a balanced hand conventionally. In some situations where 4NT is a quantitative invitation, especially where 4 is a jump, many partnerships use the Gerber convention
by some analogy to the Blackwood family: 4 asks for the number of aces or key cards.
Where both sides are bidding, 4NT is likely to be a conventional takeout asking partner to help choose one of two or three suits, similar to a lower-level takeout double or cue reply to a double.
The continuation bid of 5NT asks for the number of kings according to the same code of replies at the six-level: 6 shows no kings or four, etc. Asking for the number of kings confirms that the partnership holds all four aces, so partner may reply at the seven level with expectation of taking thirteen tricks. (A common agreement is that when spades is not the trump suit, 5♠ asks respondent to bid 5NT. That is useful when the reply to 4NT bypasses the intended trump suit but also shows that slam is likely to be a poor contract because two aces are missing.)
A void may be as good as an ace in some situations but it should not be counted as an ace. Some experts (Kantar for one) recommend the 5NT reply to 4NT – the cheapest with no standardly assigned meaning – to show a void plus two aces and six of a suit to show a void in the bid suit plus one ace.
Although the replies to 4NT are more compressed, it is almost always possible to infer which number of keycards is correct: 0 or 3, 1 or 4, 2 or 5. Evidence for that inference includes the entire auction as well as the number of key cards that the 4NT bidder holds.
The 5 and 5 replies with 2 of 5 key cards also deny and show the trump queen respectively. (Respondent may also show the queen with extra length in trumps, where the ace and king will probably draw all outstanding cards in the suit.)
The 5 and 5 replies tell nothing about the queen or extra length, but the 4NT bidder may ask about that using the cheapest bid other than five of the trump suit. The code for replies to that "queen ask" vary; a common rule is that the cheapest bid in the trump suit denies the queen or extra length and any other call shows it.
Roman Key Card Blackwood is predicated on existence of a trump suit, which determines which of the four kings and queens respondent should show as key cards. Trump agreement is not necessary, however. One common rule is that the last suit bid before 4NT bid is the key suit, lacking trump agreement.
in the 1960s. In Roman Blackwood, the responses are even more ambiguous, but more space-conserving. The basic outline of responses is:
In practice, the ambiguity is unlikely to occur, as a strength difference between hands with 0 or 1 and 3 or 4 aces is big enough that it can be established in previous rounds of bidding. In other words, a partner who has previously shown, for example, 12-15 range of high points is unlikely to hold 3 aces for his bid, etc.
Even Roman Blackwood convention has several variations, revolving around 5 and 5 responses. In all variants, they denote 2 aces. One variation is that 5 shows extra values, while 5 does not. In other variations, responses 5 - 5NT denote specific combinations of aces (same color, same rank, or "mixed").
If the querying partner ascertains that all aces are present, he can continue as follows:
in accordance with the Useful space principle
. The step responses are the same as in RKCB, but the ask is not necessarily 4NT. Instead it is the 4-level bid immediately above the agreed trump suit; i.e.:
Kickback has the advantage that it saves bidding space and, especially for minor-suit fits, provides safety at the 5-level if the required key cards are missing. Because the Kickback bid would otherwise be a control bid, 4NT is usually substituted as the control bid in that suit (e.g., 4NT is a control bid in hearts if the agreed trump suit is diamonds). The drawback is that in unpracticed partnerships there can be confusion as to whether a bid is Kickback, a control bid or preference for a different strain:
East intended 4 as Kickback, but West thought it was secondary support for hearts, and decided to pass with minimum values. As result, a reasonable grand slam in diamonds was missed.
An established partnership might have agreed that as hearts were not supported after opener's rebid, 4 cannot possibly show support, and must be ace asking in diamonds.
4– RKCB for clubs
4– RKCB for diamonds
Using "Redwood," the ace/key card ask of 4NT is still used when the trump suit is a major (hearts or spades).
4– RKCB for clubs
4– RKCB for diamonds
as 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 Key Card Blackwood, with only four key cards: 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 5, 5 and 5 present a Voidwood, denoting the void in the suit bid and asking for other key cards. The responses are, as in RKCB:
Often non-experts ask for aces when they really need other information from partner, acting act as if the convention is designed to ascertain whether the partnership holds all of the four aces or five key-cards. In fact the fundamental purpose should usually be to distinguish between lacking one and lacking two, because lacking two aces makes slam a bad bet. In other words, ace and key-card asking conventions should normally be used by one member of a partnership who plans at least to contract for 12 tricks if no more than one ace or key card is lacking.
A simplified 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. 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 a minor is the agreed trump suit, or the key suit when no trump suit is agreed. 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. In these cases experts agree on using the Kickback or Redwood convention to save steps and be able to stop at 5 or 5. An alternative is to avoid using any type of Ace asking and use the cue bid alternative.
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. A common agreement is that the first non-suit asks responder to bid 5NT. Whenever the first non-suit is a "queen ask", then the next non-suit asks to bid 5NT. This has to be planned in advance as if there is no such space partners have to bid a usually unmakeable slam contract.
Card game
A card game is any game using playing cards as the primary device with which the game is played, be they traditional or game-specific. Countless card games exist, including families of related games...
contract bridge
Contract bridge
Contract bridge, usually known simply as bridge, is a trick-taking card game using a standard deck of 52 playing cards played by four players in two competing partnerships with partners sitting opposite each other around a small table...
, the Blackwood convention is a popular bidding convention that was developed by Easley Blackwood
Easley Blackwood Sr.
Easley Rutland Blackwood , American contract bridge player and author and inventor of the Blackwood convention used in bridge bidding....
. It is used to explore the partnership's possession of aces, kings and in some variants, the queen of trumps, to judge more precisely whether slam is likely to be a good contract.
Two versions of Blackwood are common: "standard" Blackwood, developed by Easley, and "Roman key card" or "RKC" Blackwood, named for the Italian team which invented it. Standard Blackwood enables one partner to count partnership aces and kings in general. Key card variants are defined by a particular "key" suit and enable counting the trump king and queen, as well as aces and kings. Both versions are initiated by a bid of four notrump (4NT), and the entire family of conventions may be called Blackwood 4NT in both versions, or Key Card 4NT in the key card variation.
There are other 4NT conventions, such as Norman four notrump
Norman four notrump
Norman four notrump is a slam bidding convention in the partnership card game contract bridge designed to help the partnership choose among the five-, six-, and seven-levels for the final contract...
, San Francisco
San Francisco convention
In the partnership card game contract bridge, the San Francisco convention is a slam bidding convention, or a special usage by partnership agreement in order to help choose among the five, six, and seven levels for the final contract. One partner bids 4NT to ask, and the other replies, in code,...
and Byzantine Blackwood
Byzantine Blackwood convention
Byzantine Blackwood is a bidding convention used in the game of bridge. It is a complex variation of the Blackwood convention devised by Jack Marx of Great Britain which uses a four notrump to enquire about the holdings of partner...
, but almost all bridge partnerships employ some member of the Blackwood family as part of their slam-investigation methods.
If the partnership's preceding call is a natural bid in notrump, then 4NT is also natural. Over an opposing pass it is simply a raise and a quantitative invitation to six notrump, a small slam. Over a four of a suit it is likely to be a competitive raise, expecting to play four notrump. Those natural interpretations may hold in other auctions where the partnership has previously bid notrump naturally or shown a balanced hand conventionally. In some situations where 4NT is a quantitative invitation, especially where 4 is a jump, many partnerships use the Gerber convention
Gerber convention
Gerber is a contract bridge convention devised by Dr. William Konigsberger and Win Nye from Switzerland who published it in 1936; John Gerber of Texas introduced it to North America in 1938 where it was named after him...
by some analogy to the Blackwood family: 4 asks for the number of aces or key cards.
Where both sides are bidding, 4NT is likely to be a conventional takeout asking partner to help choose one of two or three suits, similar to a lower-level takeout double or cue reply to a double.
Standard Blackwood
Where standard Blackwood 4NT is in force, a four notrump bid (4NT) asks partner to disclose the number of aces in his hand. With no aces or four, partner replies 5; with one, two, or three aces, 5, 5, or 5, respectively. The difference between no aces and four is clear to the Blackwood bidder (unless the partnership lacks all four) so one member of the partnership knows the combined number of aces. That is often sufficient to set the final contract.The continuation bid of 5NT asks for the number of kings according to the same code of replies at the six-level: 6 shows no kings or four, etc. Asking for the number of kings confirms that the partnership holds all four aces, so partner may reply at the seven level with expectation of taking thirteen tricks. (A common agreement is that when spades is not the trump suit, 5♠ asks respondent to bid 5NT. That is useful when the reply to 4NT bypasses the intended trump suit but also shows that slam is likely to be a poor contract because two aces are missing.)
A void may be as good as an ace in some situations but it should not be counted as an ace. Some experts (Kantar for one) recommend the 5NT reply to 4NT – the cheapest with no standardly assigned meaning – to show a void plus two aces and six of a suit to show a void in the bid suit plus one ace.
Roman Key Card Blackwood (RKCB)
Roman Key Card Blackwood (RKCB) has largely replaced the standard version among tournament players. It developed from the Roman Blackwood variant (see below). According to RKCB there are five equivalent key cards rather than four aces; the trump king is counted as one. The key card replies to 4NT are more compressed than standard ones and they also begin to locate the queen of trumps.| 5 | – 0 or 3 key cards |
| 5 | – 1 or 4 key cards |
| 5 | – 2 or 5 cards without the trump queen |
| 5 | – 2 or 5 key cards with the trump queen |
Although the replies to 4NT are more compressed, it is almost always possible to infer which number of keycards is correct: 0 or 3, 1 or 4, 2 or 5. Evidence for that inference includes the entire auction as well as the number of key cards that the 4NT bidder holds.
The 5 and 5 replies with 2 of 5 key cards also deny and show the trump queen respectively. (Respondent may also show the queen with extra length in trumps, where the ace and king will probably draw all outstanding cards in the suit.)
The 5 and 5 replies tell nothing about the queen or extra length, but the 4NT bidder may ask about that using the cheapest bid other than five of the trump suit. The code for replies to that "queen ask" vary; a common rule is that the cheapest bid in the trump suit denies the queen or extra length and any other call shows it.
Roman Key Card Blackwood is predicated on existence of a trump suit, which determines which of the four kings and queens respondent should show as key cards. Trump agreement is not necessary, however. One common rule is that the last suit bid before 4NT bid is the key suit, lacking trump agreement.
1430 RKCB
Some partnerships use the club response to show 1 or 4 and the diamond response to show 3 or none; this is referred to as "1430" while the original version is "0314". In order to facilitate the Queen asking, an experts' version has been developed, where "1430" is used by the strong hand and "0314" is used by the weak hand. There are specific rules which determine when the asker hand is the weak one and when it is the strong one.Roman Blackwood
A variation of the standard Blackwood convention, known as Roman Blackwood, was popularized by the famous Italian Blue TeamBlue team (bridge)
The Blue Team represented Italy in international contract bridge tournaments, winning sixteen world titles from 1957 through 1975. From 1964 to 1969 and during a 1972 comeback, the team comprised three regular pairs: Walter Avarelli–Giorgio Belladonna, Pietro Forquet–Benito Garozzo, and Massimo...
in the 1960s. In Roman Blackwood, the responses are even more ambiguous, but more space-conserving. The basic outline of responses is:
| 5 | – 0 or 3 aces |
| 5 | – 1 or 4 aces |
| 5 | – 2 aces |
In practice, the ambiguity is unlikely to occur, as a strength difference between hands with 0 or 1 and 3 or 4 aces is big enough that it can be established in previous rounds of bidding. In other words, a partner who has previously shown, for example, 12-15 range of high points is unlikely to hold 3 aces for his bid, etc.
Even Roman Blackwood convention has several variations, revolving around 5 and 5 responses. In all variants, they denote 2 aces. One variation is that 5 shows extra values, while 5 does not. In other variations, responses 5 - 5NT denote specific combinations of aces (same color, same rank, or "mixed").
If the querying partner ascertains that all aces are present, he can continue as follows:
- 5NT is the Grand slam forceGrand slam forceThe Grand Slam Force is a bidding convention in contract bridge that was developed by Ely Culbertson in 1936. It is intended to be used in cases where the combined hands of a partnership are so strong that a slam is a near-certainty and a grand slam is a possibility...
- The first available bid which is not the agreed suit is the Roman Blackwood for kings. The partner responds stepwise, as above.
Kickback
"Kickback" is the variant of RKCB devised by Jeff RubensJeff Rubens
Jeff Rubens is a bridge player and writer; he is the editor of the magazine The Bridge World and the author of several bridge books, including Secrets of Winning Bridge....
in accordance with the Useful space principle
Useful space principle
The Useful Space Principle, or USP, was first articulated in a series of six articles in The Bridge World, from November 1980 through April 1981...
. The step responses are the same as in RKCB, but the ask is not necessarily 4NT. Instead it is the 4-level bid immediately above the agreed trump suit; i.e.:
| 4 | – RKCB for clubs |
| 4 | – RKCB for diamonds |
| 4 | – RKCB for hearts |
| 4NT | – RKCB for spades |
Kickback has the advantage that it saves bidding space and, especially for minor-suit fits, provides safety at the 5-level if the required key cards are missing. Because the Kickback bid would otherwise be a control bid, 4NT is usually substituted as the control bid in that suit (e.g., 4NT is a control bid in hearts if the agreed trump suit is diamonds). The drawback is that in unpracticed partnerships there can be confusion as to whether a bid is Kickback, a control bid or preference for a different strain:
| West | East |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 4 | 4 |
| Pass |
An established partnership might have agreed that as hearts were not supported after opener's rebid, 4 cannot possibly show support, and must be ace asking in diamonds.
Redwood
"Redwood" is a variation of Kickback, in which the kickback principle is used only when a minor suit is trumps. The name comes from the fact that the resulting ace/key card ask will be a red suit:4– RKCB for clubs
4– RKCB for diamonds
Using "Redwood," the ace/key card ask of 4NT is still used when the trump suit is a major (hearts or spades).
Minorwood
"Minorwood" is a variation of Blackwood, in which the minor suit which the partners agree will be trumps is itself used as the ace/key card ask. The ask will be at the four level. Hence:4– RKCB for clubs
4– RKCB for diamonds
Exclusion Blackwood
Exclusion Blackwood or Voidwood. was devised by Bobby GoldmanBobby Goldman
Robert Goldman was an American bridge player, teacher and author. He won three Bermuda Bowls , Olympiad Mixed Teams 1972, and 20 North American Bridge Championships...
as 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 Key Card Blackwood, with only four key cards: 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:
| West | East |
|---|---|
| 1 | 3 |
| 5 |
- 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 with trump queen
Application
When the Blackwood bidder has a void, and partner shows one or more but not all missing aces, "asker" will not know whether partner's ace duplicates the void suit (where it would not be of great help) or covers side suit losers. For this reason cue bid to show aces explicitly, or Exclusion or Voidwood convention to ask for useful aces, is used with hands that contain a void.Often non-experts ask for aces when they really need other information from partner, acting act as if the convention is designed to ascertain whether the partnership holds all of the four aces or five key-cards. In fact the fundamental purpose should usually be to distinguish between lacking one and lacking two, because lacking two aces makes slam a bad bet. In other words, ace and key-card asking conventions should normally be used by one member of a partnership who plans at least to contract for 12 tricks if no more than one ace or key card is lacking.
A simplified 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. 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 a minor is the agreed trump suit, or the key suit when no trump suit is agreed. 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. In these cases experts agree on using the Kickback or Redwood convention to save steps and be able to stop at 5 or 5. An alternative is to avoid using any type of Ace asking and use the cue bid alternative.
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. A common agreement is that the first non-suit asks responder to bid 5NT. Whenever the first non-suit is a "queen ask", then the next non-suit asks to bid 5NT. This has to be planned in advance as if there is no such space partners have to bid a usually unmakeable slam contract.
See also
- Grand slam forceGrand slam forceThe Grand Slam Force is a bidding convention in contract bridge that was developed by Ely Culbertson in 1936. It is intended to be used in cases where the combined hands of a partnership are so strong that a slam is a near-certainty and a grand slam is a possibility...
- Norman four notrumpNorman four notrumpNorman four notrump is a slam bidding convention in the partnership card game contract bridge designed to help the partnership choose among the five-, six-, and seven-levels for the final contract...
- Quantitative no trump bidsQuantitative no trump bidsIn natural bidding systems most notrump bids are made with balanced hands and within a narrowly defined high card point range. In these systems, such as Acol and Standard American, NT bids are limit bids and therefore are not forcing...
- Slam-seeking conventionsSlam-seeking conventionsSlam-seeking conventions are codified artificial bids used in the card game contract bridge. Bidding and making a small slam or grand slam yields high bonuses ranging from 500 to 1500 points. However, the risk is also high as failure to fulfill the slam contract also means failure to score the...
Further reading
- Ron KlingerRon KlingerRon Klinger is a leading bridge author, writing more than 50 books on the game. He is an Australian Grand Master and a World Bridge Federation International Master.-Biography:...
, collab Husband & Kambites. (1994) Basic Bridge Victor GollanczVictor GollanczSir Victor Gollancz was a British publisher, socialist, and humanitarian.-Early life:Born in Maida Vale, London, he was the son of a wholesale jeweller and nephew of Rabbi Professor Sir Hermann Gollancz and Professor Sir Israel Gollancz; after being educated at St Paul's School, London and taking...
, London, UK. ISBN 0-575-05690-8 - Paul MendelsonPaul MendelsonPaul Mendelson is a television, film and radio scriptwriter.- Early life and career :He studied Law at Cambridge University, where he gained a first class honours degree, after attending Newcastle Royal Grammar School, Glasgow High School and Harrow County Grammar...
, 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 HamlynPaul HamlynPaul Hamlyn, Baron Hamlyn of Edgeworth, CBE , was a German-born British publisher and philanthropist.-Family:...
, 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 GollanczVictor GollanczSir Victor Gollancz was a British publisher, socialist, and humanitarian.-Early life:Born in Maida Vale, London, he was the son of a wholesale jeweller and nephew of Rabbi Professor Sir Hermann Gollancz and Professor Sir Israel Gollancz; after being educated at St Paul's School, London and taking...
in association with Peter CrawleyPeter CrawleyPeter Crawley was a British bare-knuckle boxer. He became Heavyweight Championship of England in 1827.-1816-1817:*Bill Hunt - WIN*Jack Bennett - WIN*Tom Price - WIN...
, London, UK. ISBN 0-575-05253-8 - Eddie Kantar, Roman Keycard Blackwood: The Final Word (2008) Master Point PressMaster Point PressMaster Point Press is a Canadian book publishing company located in Toronto, Canada. It grew out of Canadian Master Point magazine , which was published by Ray and Linda Lee. The company began publishing books in 1994...
, Toronto, Canada ISBN 978-1-897106-35-8
External links
- [www.bridgebum.com/roman_key_card_blackwood.php "Roman Key Card Blackwood" at BridgeBum]
- "Roman Key Card Blackwood" (broken link) at BridgeGuys
- "Roman Blackwood" at BridgeGuys
- "Blue Team Roman Blackwood" at BridgeGuys
- "Exclusion Keycard Blackwood" at BridgeGuys
- Eddie Kantar's bidding tips