A reverse, in the card game contract bridge, is a bidding sequence designed to show additional strength without the need to make a jump bid; specifically two suits are bid in the reverse order to that expected by the basic bidding system. Precise methods and definitions vary with country, bidding system and partnership agreements.
In Standard American a reverse is defined by William S. Root [1] as "... a non-jump bid at the two-level in a new suit that ranks higher than the suit you bid first", and by Bridge World. [2] as "a non-jump bid in a new suit that bypasses a bid in a lower-ranking suit already bid by the same player".
The Acol definition is somewhat wider and includes any bid of a new suit by opener higher than two of their first suit. [3]
In the auction, 1♣ – 1♠; 2♥, the 2♥ rebid by opener meets the foregoing definitions and is a reverse showing a stronger than minimum opening hand and forcing responder to bid for one more round.
Responder's bid of 1♠ bypassed bids of 1♦ and 1♥ creating a "gap" in the auction (between the 1♣ and 1♠ bids) thereby implying that responder did not possess four or more in either of those suits. Despite this, opener rebid 2♥, apparently seeking a fit in hearts that is unlikely to exist. This seemingly odd bidding is the "reverse" of what one would expect with a minimum opening hand because such action would compel a responder, who holds a minimum hand for his 1♠ bid but with no hearts and only a few clubs, to return opener to his club suit at the three-level, a result likely to be too high for two minimum hands but not if opener has a strong hand.
One way to identify a reverse is to recognize that a "gap" has been created and that the opener has bid a second suit which lies within the "gap", hearts or diamonds in this example.
Depending on the bidding system, a reverse by opener usually shows a minimum of 16 points or a five-loser hand and at least five cards in the first bid suit.
Opener's reverse may face a weak responding hand with which responder may have intended (over a simple suit rebid) to rebid his own suit or taken a preference to opener's first suit at the two level. Opener's reverse still allows responder to rebid his suit at the two level, but a preference to opener's first suit must be at the three level. Thus, opener's reverse must show values at least one trick beyond the minimum needed to open.
For example, following 1♦ – 1♠ ; 2♥ – ?, responder may have a weak hand such as ♠QJ86 ♥K2 ♦8762 ♣Q74 and be planning to rebid 2♦, a simple preference, if opener made a typical rebid such as 1NT or 2♣, and to pass if opener rebid 2♠ or 2♦. However, following the reverse, he must now rebid 3♦. Thus the reverse has forced the partnership to commit to taking nine tricks instead of eight - based on the extra strength of opener.
Examples of reverse bidding sequences:
A special case exists when responder makes a two-over-one initial bid. Since a two-over-one response shows more than a minimum, generally ten or more, opener does not need as strong a hand to reverse the bidding at that juncture. The modern trend is therefore to allow such a reverse bid after a two-over-one initial response with a minimum opening hand. [4]
Opener's reverse need not be in a four-card or longer suit; it can be made on a powerful three-card minor suit, such as ♦AQJ. This approach is useful in investigating notrump contracts and when no other four-card suit is available to bid.
Reverse bids are generally considered to be forcing, with subtle variations depending on system:
These examples illustrate high and low level reverses:
In some variants of 2/1 game forcing, the major-suit reverse after the sequence 1♦ – 2♣ doesn't promise extra values — opener may merely show a 4-card suit or a stopper. [5] Kaplan–Sheinwold treats 1♦ – 1M; 2♣ as a reverse although this is not standard in other systems.
Most partnerships play a rebid of responder's suit or of 2NT in response to opener's reverse as weak and other responses as forcing to game, including preference for the opening suit. Thus, after
responder's rebids are:
Most standard methods treat a responder's reverse as a game force. Responder's reverse usually follows a same suit rebid or a notrump rebid by opener, because otherwise it would be treated as conventional. Typical responder's reverse sequences are:
The term "jump reverse" denotes a jump bid in a suit in which a non-jump bid would be a reverse. Jump reverses after a major-suit response carry a special meaning. Most expert partnerships utilise this bid to denote game-going values with shortness (often specifically a singleton) in the suit bid and support for partner's major suit. An example of a jump reverse is:
1♣ – 1♠; 3♥
Partnerships utilising this agreement commonly agree that in this situation a splinter bid (i.e. a double jump in a new suit) indicates a void. [6] This is also the understanding used in Bridge World Standard, though other options may also be used.
Jump reverses after a minor-suit response commonly show splinter raises, too.
1♦ – 2♣; 3♥
Jump reverses after a 1NT response to a minor opening are often used to indicate game-going values with shortness in the suit bid (a singleton or void) and six cards or more in the minor suit opened. This agreement facilitates partner in deciding the final contract (in most cases 3NT or a game or slam in the opened minor).
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.
2/1 game forcing is a bidding system in modern contract bridge structured around the following responses to a one-level opening bid:
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 a natural system using four-card majors and, most commonly, a weak no trump.
Polish Club is a bridge bidding system which was developed in Poland, where it is the most popular bidding system, and which is also used by players of other countries. It is a type of small club system.
The Drury convention is a bridge convention, used to show a game-invitational major suit raise by a passed hand while guarding against a light opening by partner in third or fourth seat. It is initiated by an artificial and forcing 2♣ response by the passed hand to a 1♥ or 1♠ opening by partner. The 2♣ bid shows at least 3-card support for opener's suit with 10-12 support points and asks opener to clarify the strength of their opening hand. The convention is also known in Europe as "Toronto".
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 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.
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.
Jacoby 2NT is a bridge convention in which a bid of 2NT over partner's opening bid of one heart or one spade shows a hand with both
Multi coloured 2 diamonds, or simply Multi, is a contract bridge convention whereby the opening bid of 2♦ shows several possible types of hands. These always include a weak-two bid in a major suit; 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.
Bridge bidding systems that incorporate a strong 2 clubs opening bid include modern Standard American, standard Acol, 2/1 game forcing and many others.
The Kaplan–Sheinwold bidding system was developed and popularized by Edgar Kaplan and Alfred Sheinwold during their partnership, which flourished during the 1950s and 1960s. K-S is one of many natural systems. The system was definitively described in their 1958 book How to Play Winning Bridge and later revised and retitled to The Kaplan-Sheinwold System of Winning Bridge in 1963.
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.
EHAA is a highly natural bidding system in contract bridge characterized by four-card majors, sound opening bids, undisciplined weak two-bids in all four suits and a mini notrump, usually of 10–12 high card points.
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.
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.
Transfer Walsh is a bidding convention used in contract bridge. After a 1♣ opening bid, responses of 1♦ and 1♥ show heart and spade suits respectively. The "Walsh" terminology refers to the fact that these bids may conceal an equal or longer diamond suit. It allows opener to play a greater proportion of major-suit and no-trump contracts, particularly when using five-card majors.
Blackout is a bridge convention for responding to a reverse bid after a one-over-one beginning, whereby the responder can show whether or not he has better than a minimum response. Responder makes the cheapest bid from either the fourth suit or 2NT to show a hand that has no game interest. All other bids show reasonable hands, generally in the eight point range and are game-forcing. The objective of Blackout is to allow the constructive game-going hands to keep the bidding level low and give more room for the strong auctions that may lead to slams. The convention is also known as Wolff Over Reverses.