The Grand Slam Force is a bidding convention in contract bridge that was developed by Ely Culbertson in 1936. [1] It is intended to be used in cases where the combined hands of a partnership are so strong that a slam (winning at least 12 tricks) is a near-certainty and a grand slam (winning all 13 tricks) is a possibility. It enables a player to gain information about the quality of the top trumps held by his partner (i.e., which of the ace, king or queen).
When the Grand Slam Force was invented in the 1930s (when it was called "Josephine," named after Josephine Culbertson), Blackwood had not evolved into what has become the standard: Roman Keycard Blackwood (often called RKCB). Using KCB, there are 5 keycards -- the four aces and the king of trumps. The responses to 4NT are: 5C = 1 or 4 keycards; 5D = 0 or 3 keycards; 5H = 2 keycards without the Queen of trumps; 5S = 2 keycards with the Queen of trumps. As you can see, there is no need to bid 5NT to ask for the A, K, and Q of trumps. These days, the only time the Grand Slam Force is used is when partner opens the bidding or when the opener and responder have voids. In fact, 5NT is now used almost exclusively as "5NT Pick-A-Slam."
When this convention is in force, a bid of 5NT (five notrump), when it does not conflict with other conventions used by that partnership (e.g., a 5NT Blackwood bid), is forcing to slam in the suit last bid, unless the trump suit has already been agreed on earlier in the auction. The partner of the 5NT bidder bids as follows:
Actually, the previous sentence is the way the convention used to be used -- but these days, respond 7C with 2 of the top 3. Maybe partner has his own trump suit which is better than opener's, but responder has potential losers in opener's suit.
For example, if a partnership is using the Grand Slam Force and one member bids 1♥ and his partner bids 5NT, it is implied that hearts are the desired trump suit. The original bidder will sign off in 6♥ with one of the top three heart honors and 7♥ with two of the top three heart honors.
As with all bidding systems, the Grand Slam Force has its limitations, not the least of which is that the chances of employing it directly over an opening one-bid are extremely rare and 5NT must be understood to be the GSF in other situations. Numerous variations of the convention have been developed.
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.
Stayman is a bidding convention in the card game contract bridge. It is used by a partnership to find a 4-4 or 5-3 trump fit in a major suit after making a one notrump (1NT) opening bid and it has been adapted for use after a 2NT opening, a 1NT overcall, and many other natural notrump bids.
Standard American is a bidding system for the game of bridge widely used in North America and elsewhere. Owing to the popularization of the game by Charles Goren in the 1940s and 1950s, its early versions were sometimes referred to simply as 'Goren'. With the addition and evolution of various treatments and conventions, it is now more generally referred to as Standard American. It is a bidding system based on five-card majors and a strong notrump; players may add conventions and refine the meanings of bids through partnership agreements summarized in their convention card. One standardised version, SAYC, is widely used by casual partnerships and in online bridge.
The Jacoby transfer, or simply transfers, in the card game contract bridge, is a convention in most bridge bidding systems initiated by responder following partner's notrump opening bid that forces opener to rebid in the suit ranked just above that bid by responder. For example, a response in diamonds forces a rebid in hearts and a response in hearts forces a rebid in spades. Transfers are used to show a weak hand with a long major suit, and to ensure that opener declare the hand if the final contract is in the suit transferred to, preventing the opponents from seeing the cards of the stronger hand.
Zar Points (ZP) is a statistically derived method for evaluating contract bridge hands developed by Zar Petkov. The statistical research Petkov conducted in the areas of hand evaluation and bidding is useful to bridge players, regardless of their bidding or hand evaluation system. The research showed that the Milton Work point count method, even when adjusted for distribution, is not sufficiently accurate in evaluating all hands. As a result, players often make incorrect or sub-optimal bids. Zar Points are designed to take many additional factors into consideration by assigning points to each factor based on statistical weight. While most of these factors are already implicitly taken into account by experienced players, Zar Points provides a quantitative method that allows them to be incorporated into bidding.
These terms are used in contract bridge, using duplicate or rubber scoring. Some of them are also used in whist, bid whist, the obsolete game auction bridge, and other trick-taking games. This glossary supplements the Glossary of card game terms.
In contract bridge, various bidding systems have been devised to enable partners to describe their hands to each other so that they may reach the optimum contract. Key to this process is that players evaluate and re-evaluate the trick-taking potential of their hands as the auction proceeds and additional information about partner's hand and the opponent's hands becomes available.
Bridge bidding systems that incorporate a strong 2 clubs opening bid include modern Standard American, standard Acol, 2/1 game forcing and many others.
Slam-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 bonus points for a game (300-500). Conventions have been devised to maximise the opportunity for success whilst minimising the risk of failure.
Gerber is a contract bridge convention devised by 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. It is similar to Blackwood but uses 4♣ instead of 4NT as a relay (asking) bid to inquire about the number of aces held by partner. A further relay bid may follow to inquire about the number of kings held.
In contract bridge, a cue bid is either a bid of the opponents' suit, or "slam seeking": a slam-investigating bid made during an auction's later rounds that shows control of a suit.
In contract bridge, an overcall is a bid made after an opening bid has been made by an opponent; the term refers only to the first such bid. A direct overcall is such a bid made by the player seated immediately to the left of the opener, i.e. next in the bidding rotation; an overcall in the 'last seat', i.e. by the player to the right of opener, which is made after two intervening passes, is referred to as a balancing or protective overcall.
The Useful Space Principle, or USP, in the game of contract bridge was first articulated in a series of six articles in The Bridge World, from November 1980 through April 1981. The USP is expressed succinctly in The Bridge World glossary as: "a partnership's assigning meanings to actions so that the remaining bidding space matches the needs of the auction."
Inverted minors refers to a treatment introduced by the Kaplan–Sheinwold (K–S) bidding system for the popular card game bridge. The original structure of Precision, another bidding system, also employed inverted minors over a 1♦ opening. However, the treatment is no longer restricted to users of these bidding systems. although partnerships that use a Short club system tend also to use the convention only after a 1♦ opener.
In the card game contract bridge, Gambling 3NT is a special treatment of an opening bid of 3NT. The bid is used to describe a hand containing a minor suit of at least seven cards in length and headed by the ace, king and queen, at minimum. The bid has the dual objectives of preempting the opponents' bidding should they hold the majors and trying for a game in notrump on the gamble that partner might hold adequate support.
New Minor Forcing (NMF), is a contract bridge bidding convention used to find a 5-3 or 4-4 major suit fit after a specific sequence of bids in which opener has rebid one notrump. The convention is triggered by responder at his second turn by an artificial bid of two in an unbid minor; it requires that he hold five cards in the major he has previously bid and an unlimited hand ranging in value from at least game invitational strength to that sufficient to have interest in slam; he may also hold four cards in the other major. Accordingly, there are six bidding sequences in which the New Minor Forcing bid may be applied:
Bridge base basic, also known as BBO basic, is a bidding system for the game of bridge based on the Standard American Yellow Card (SAYC). It is simplified, suitable for beginners, and widely used in internet bridge, particularly on Bridge Base Online. It is taught in Fred Gitelman's educational software called Learn to Play Bridge that is available as a free download from the American Contract Bridge League's website.
The Carrot 4NT slam-convention was developed in Carrot Club, but can be used in any bidding system instead of the more common Blackwood or RKC conventions. It is a refinement of an older convention, Culbertson 4NT.
Byzantine Blackwood is a bidding convention in the game of bridge. Devised by Jack Marx, it is a complex version of the Blackwood convention. Its premise is that both aces and kings may safely be shown in response to a Blackwood-type 4NT enquiry; provided that such kings are in well-defined key or half-key suits, there being no more than two such suits. The name was chosen to express the idea that Byzantine Blackwood is a development from Roman Blackwood, by analogy with the Byzantine Empire and the Roman Empire; rather than that the convention is of Byzantine complexity. It seems to be little used nowadays (2014), most experts employing some form of Roman Key Card Blackwood.
In contract bridge, an asking bid is a convention used to seek a slam accurately. There are two types - colour asking bids and notrump asking bids. Constructed by bridge pioneer Ely Culbertson in the 1940s, they have been superseded by other methods; however, one remaining commonly used asking bid is the 5NT Grand slam force.