The origin of this conventional method is unknown. It is also known under the designation of the San Francisco Convention. The conventional method is also known under the designation California Blackwood. The reason for these additional designations may be regional or even geographical.

Note: it is possible that this concept was developed by Emily Stanley Warren, later Mrs. Emily Stanley Prescott, possibly together Mrs. Elizabeth Clark Boyden of New York, New York, United States. This statement, however, is pure speculation until additional information is forthcoming. These two pioneering women of the 1920s and 1930s were active on the social level in attempting to create a play and recreational scene within the environment of the social establishment. As partners in many endeavors, also including Backgammon, Ma Chiang, and Camelot they also became adherents of the new and developing game of Auction Bridge, Contract Bridge, and Duplicate Bridge.

Among their publications are Auction And Contract Bridge Condensed, published in 1927, and Pocket Contract Bridge: The Culbertson Forcing System (Official), published c1931.

Note: The written English designation for the game of Ma Chiang is correct, but the name is generally written as Mahjong or Mah Jongg.

Note: The game of Camelot is an abstract strategy board game played between two players on a board of 160 squares. Each player begins the game with 14 pieces, namely four Knights and ten Men. The pieces utilize three different move types: Plain Move (one square, any direction), Canter (leap over friendly pieces), and Jump (leap over and capture enemy pieces). Knights may combine Canters and Jumps in a single move. The game is won either by moving any two pieces into the opponent's Castle, or by capturing all of the opponent's pieces.

Principle of the Concept

It is a variation of the concept known and designated as the Norman convention. This variation allows the partnership to more accurately identify the honors after the trump suit has been established in a slam attempt.

It was used by many bridge players when the game of bridge was evolving and it is also, to some degree, very similar to the concept of the Culbertson Four-Five No Trump convention.

The 4 No Trump bidder, after the trump suit has been established or inferred, is required to hold at least two Aces before being able to make this bid. The responses by the partner show the holding of both Aces and Kings by using only one bid. In order to accomplish this, the Aces are counted as 3 points and the Kings as 1 point, and the responses are as follows:

Partner   Responder Meaning
4 NT   5 Shows fewer than 3 points: no Ace and at most 2 Kings.
    5 Shows 3 points: 1 Ace and no Kings, or 3 Kings.
    5 Shows 4 points: 1 Ace and 1 King, or 4 Kings.
    5 Shows 5 points: 1 Ace and 2 Kings.
    5 NT Shows 5 points: 1 Ace and 3 Kings, or 2 Aces.
    6 Shows 7 points: 2 Aces and 1 King, or 1 Ace and 4 Kings.
    6 Shows 8 points: 2 Aces and 2 Kings.
    6 Shows 9 points: 2 Aces and 3 Kings.
    6 Shows 10 points: 2 Aces and 4 Kings.

Alternative Agreement

The responder can also show the number of points for the Aces and Kings even if the opener decides to open the auction with a strong, artificial 2 Clubs bid or, by partnership agreement, a Strong Two-Bid in any suit.

Note: The reader should remember that strong two bids in any suit was rather the norm in the early years of the game of bridge. The assignment of other, significantly different meanings to such opening bids were later developed and became gradually more accepted by the bridge community.

After such a strong opening of a suit on the two level the responder employs other bids immediately to communicate to partner the number of points held, and also to communicate mild to strong slam interest. As above, the Aces are counted as 3 points and the Kings as 1 point.

Opener Responder Meaning
2 // 5 Shows zero points.
5 Shows 1 point.
5 Shows 2 points.
5 Shows 3 points.
5 NT Shows 4 points.
6 Shows 5 points.
6 Shows 6 points.
6 Shows 7 points.
6 Shows 8 points.
6 NT Shows 9 points, etc.

In the case of strong two-bids, made in any suit, the immediate jump to the five level proves to be cumbersome upon the two players since much bidding space has been eliminated, which could have been employed to communicate more slowly additional and more accurate information. The possibility and the percentage rate of inaccuracy of final contract placement are increased since the opener must decide as to the location of Aces and Kings shown by the responder's bid by inference, but also to eventually be faced with the knowledge that a response on the six level places the partnership already in perhaps an unsecured contract.



If you wish to include this feature, or any other feature, of the game of bridge in your partnership agreement, then please make certain that the concept is understood by both partners. Be aware whether or not the feature is alertable or not and whether an announcement should or must be made. Check with the governing body and/or the bridge district and/or the bridge unit prior to the game to establish the guidelines applied. Please include the particular feature on your convention card in order that your opponents are also aware of this feature during the bidding process, since this information must be made known to them according to the Laws of Duplicate Contract Bridge. We do not always include the procedure regarding Alerts and/or Announcements, since these regulations are changed and revised during time by the governing body. It is our intention only to present the information as concisely and as accurately as possible.


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