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.
Acol is the bridge bidding system that, according to The Official Encyclopedia of Bridge, is "standard in British tournament play and widely used in other parts of the world". It is basically a natural system using four-card majors and, most commonly, a weak no trump.
A game try in the card game of bridge is a bid that shows interest in bidding a game and asks partner to help in making the decision.
The forcing notrump is a bidding convention in the card game of bridge.
The Jacoby transfer, or simply transfers, in the card game contract bridge, is a convention in Standard American 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.
The weak two bid is a common treatment used in the game of contract bridge, where an opening bid of two diamonds, hearts or spades signifies a weak hand with a long suit. It is used in combination with the strong two clubs bid and is a form of preemptive bid. The term refers to an opening bid, and is not to be confused with the "weak jump overcall", which denotes a similar type of hand, but is bid over an opponent's opening bid.
Cappelletti is a bridge bidding convention for the card game contract bridge, primarily used to interfere over opponent's one notrump (1NT) opening. Usually attributed to Michael Cappelletti and his longtime partner Edwin Lewis, origin of the concept is also claimed by Fred Hamilton, John Pottage and Gerald Helms.
Brozel is a contract bridge bidding convention used to intervene after an opposing one notrump (1NT) opening bid. It features the following calls:
Landy, named after its inventor Alvin Landy is the first of several conventional defenses created to compete against an opponent's one notrump (1NT) opening. Landy is a 2♣ overcall of the opponents' 1NT opening to show at least four cards in each of the major suits; all other bids are natural. Requirements for the overcall vary from partnership to partnership: some require 5-5, some 5-4, and yet others only 4-4. The partner can take a preference to either major or make a non-forcing bid of a suit; 2NT is used as a forcing query.
Multi 2 diamonds, or simply Multi, is a contract bridge convention whereby the opening bid of 2♦ shows multiple types of hands, which always includes a weak-two bid in either major suit, while the additional meaning may be a strong balanced hand, or a 20-22 three suiter. The inherent ambiguity as to both suit and strength makes it a powerful and popular convention capable of seriously disrupting the opponents' bidding.
Muiderberg is a bidding convention in the card game bridge. It is a two-level preemptive opening based on a two-suiter with precisely a five-card major and a minor suit. In Muiderberg the 2♥ opening denotes five hearts and an unknown minor suit, whilst 2♠ denotes five spades and an unknown minor suit. The convention is also known as the Dutch Two, Lucas Two or Woo Two opening. The convention is named after the Dutch village Muiderberg, the residence of the designers of the convention - Onno Janssens and Willem Boegem.
In the game of contract bridge, CRASH is a defense against a strong 1♣ or a 1NT opening that first appeared in 1976 in an article by Kit Woolsey in The Bridge World. Within the CRASH framework, intervening calls after the 1NT opening denote either (a) two-suited hands of the same color, the same rank, or the same shape or (b) a natural one-suited hand.
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.
Fourth suit forcing is a contract bridge convention that allows responder to create, at his second turn to bid, a forcing auction. A bid by responder in the fourth suit, the only remaining unbid suit, is artificial indicating that responder has no appropriate alternate bid, remains interested in the potential for a game contract and asks opener to bid again to show additional features.
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:
In the card game bridge, CoCa or Comfy Canapé is a conventional defense against opposing 1NT openings. When playing CoCa, over a 1NT opening of the opponents, both a double as well as a 2♣ overcall are conventional and establish spades and hearts, respectively as anchor suits. Higher overcalls can be either natural, or conventional.
Five-card majors is a contract bridge bidding treatment common to many modern bidding systems. Its basic tenet is that an opening bid of one-of-a-major in first and second position guarantees at least five cards in that major. This method has become standard in North American tournament play, but European methods vary.
