At the end of the hand, points are awarded to the declaring side if they make the contract, or else to the defenders. Partnerships can be "vulnerable, increasing the rewards for making the contract, but also increasing the penalties for undertricks. In rubber bridge, if a side has won 100 contract points, they have won a "game and are vulnerable for the remaining rounds, but in duplicate bridge, vulnerability is predetermined based on the number of each board.
If the declaring side makes their contract, they receive points for "odd tricks, or tricks bid and made in excess of six. In both rubber and duplicate bridge, the declaring side is awarded 20 points per odd trick for a contract in clubs or diamonds, and 30 points per odd trick for a contract in hearts or spades. For a contract in no trump, the declaring side is awarded 40 points for the first odd trick and 30 points for the remaining odd tricks. Contract points are doubled or quadrupled if the contract is respectively doubled or redoubled.[c]
In rubber bridge, a partnership wins one game once it has accumulated 100 contract points; excess contract points do not carry over to the next game. A partnership that wins two games wins the rubber, receiving a bonus of 500 points if the opposing side is not vulnerable, and 700 points if the opposing side is vulnerable.
Overtricks score the same number of points per odd trick, although their doubled and redoubled values differ. Bonuses vary between the two bridge variations both in score and in type (for example, rubber bridge awards a bonus for holding a certain combination of high cards), although some are common between the two.
A larger bonus is awarded if the declaring side makes a small slam or grand slam, a contract of 12 or 13 tricks respectively. If the declaring side is not vulnerable, a small slam gets 500 points, and a grand slam 1000 points. If the declaring side is vulnerable, a small slam is 750 points and a grand slam is 1500.
In rubber bridge, the rubber finishes when a partnership has won two games, but the partnership receiving the most overall points wins the rubber. Duplicate bridge is scored comparatively, meaning that the score for the hand is compared to other tables playing the same cards and match points are scored according to the comparative results: usually either "matchpoint scoring", where each partnership receives 2 (or 1) point for each pair that they beat, and 1 (or a half) point for each tie; or IMPs (international matchpoint) scoring, where the number of IMPs varies (but less than proportionately) with the points difference between the teams.
Undertricks are scored in both variations as follows:
|Undertricks||Points per undertrick|
|2nd and 3rd, each||300||600||200||400|
|4th and each subsequent||300||600||300||600|
The rules of the game are referred to as the laws as promulgated by various bridge organizations.
Laws of duplicate bridge
The official rules of duplicate bridge are promulgated by the World Bridge Federation (WBF) as the "International Code of Laws of Duplicate Bridge, 2007". The Laws Committee of the WBF, composed of world experts, updates the Laws every 10 years; it also issues a Laws Commentary advising on interpretations it has rendered.
In addition to the basic rules of play, there are many additional rules covering playing conditions and the rectification of irregularities, which are primarily for use by tournament directors who act as referees and have overall control of procedures during competitions. But various details of procedure are left to the discretion of the zonal bridge organisation for tournaments under their aegis and some (for example, the choice of movement) to the sponsoring organisation (e.g. the club).
The zonal organisations of the WBF also publish editions of the Laws. For example, the "American Contract Bridge League publishes "Laws of Duplicate Bridge, 2008", "Laws of Contract Bridge, 2003" and additional supporting documentation including: Director Decisions, Tech Files and Casebook (appeals from national bridge championships).
Rules of rubber bridge
There are no universally accepted rules for rubber bridge promulgated by bridge governing bodies; instead local rules such as The Laws of Contract Bridge as published by the "American Contract Bridge League constitute the rules for those wishing to abide by a published standard.
The majority of rules mirror those of duplicate bridge in the bidding and play and differ primarily in procedures for dealing and scoring.
Laws of online play
In 2001, the "World Bridge Federation promulgated a set of Laws for online play.
Bridge is a member of the family of "trick-taking games and is a development of "Whist, which had become the dominant such game and enjoyed a loyal following for centuries. According to the "Oxford English Dictionary, Bridge is the "English pronunciation of a game called "Biritch, which was also known as Russian Whist.
The oldest known Biritch rule book, dated 1886, is Biritch, or Russian Whist by John Collinson. It and his subsequent letter to The Saturday Review dated May 28, 1906, document the origin of Biritch as being the Russian community in Istanbul. It has some features in common with "Solo Whist. The game had many significant bridge-like developments: dealer chose the "trump suit, or nominated his partner to do so; there was a call of notrumps (biritch); dealer's partner's hand became dummy; points were scored above and below the line; game was 3NT, 4H and 5D (although 8 club odd tricks and 15 spade odd tricks were needed); the score could be doubled and redoubled; and there were slam bonuses. This game, and variants of it known as "bridge" and "bridge-whist", became popular in the United States and the United Kingdom in the 1890s despite the long-established dominance of whist.
In 1904 "auction bridge was developed, in which the players bid in a competitive auction to decide the contract and declarer. The object became to make at least as many tricks as were contracted for, and penalties were introduced for failing to do so.
The modern game of contract bridge was the result of innovations to the scoring of auction bridge by "Harold Stirling Vanderbilt and others. The most significant change was that only the tricks contracted for were scored below the line toward game or a slam bonus, a change that resulted in bidding becoming much more challenging and interesting. Also new was the concept of "vulnerability", making sacrifices to protect the lead in a rubber more expensive. The various "scores were adjusted to produce a more balanced and interesting game. Vanderbilt set out his rules in 1925, and within a few years contract bridge had so supplanted other forms of the game that "bridge" became synonymous with "contract bridge".
In the USA and many other countries, most of the bridge played today is "duplicate bridge, which is played at clubs, in tournaments and online. The number of people playing contract bridge has declined since its peak in the 1940s, when a survey found it was played in 44% of US households. The game is still widely played, especially amongst retirees, and in 2005 the ACBL estimated there were 25 million players in the US.
Bridge is a game of skill played with "randomly dealt cards, which makes it also a "game of chance, or more exactly, a tactical game with inbuilt randomness, imperfect knowledge and restricted communication. The chance element is in the deal of the cards; in duplicate bridge some of the chance element is eliminated by comparing results of multiple pairs in identical situations. This is achievable when there are eight or more players, sitting at two or more tables, and the deals from each table are preserved and passed to the next table, thereby duplicating them for the other table(s) of players. At the end of a session, the scores for each deal are compared, and the most points are awarded to the players doing the best with each particular deal. This measures skill (but still with a significant element of luck) because each pair or team is being judged only on the ability to bid with, and play, the same cards as other players. However very often even the most skillful play will only succeed some of the time, and the skilled player may be unlucky because an alternative, less expert play achieves a better result. But in the long run the expert player will score better.
Duplicate bridge is played in clubs and tournaments, which can gather as many as several hundred players. Duplicate bridge is a "mind sport, and its popularity gradually became comparable to that of "chess, with which it is often compared for its complexity and the mental skills required for high-level competition. Bridge and chess are the only "mind sports" recognized by the "International Olympic Committee, although they were not found eligible for the main "Olympic program.
The basic premise of duplicate bridge had previously been used for whist matches as early as 1857. Initially, bridge was not thought to be suitable for duplicate competition; it was not until the 1920s that (auction) bridge tournaments became popular.
In 1925 when contract bridge first evolved, bridge tournaments were becoming popular, but the rules were somewhat in flux, and several different organizing bodies were involved in tournament sponsorship: the American Bridge League (formerly the American Auction Bridge League, which changed its name in 1929), the American Whist League, and the United States Bridge Association. In 1935, the first officially recognized world championship was held. By 1937, however, the "American Contract Bridge League had come to power (a union of the ABL and the USBA), and it remains the principal organizing body for "bridge tournaments in North America. In 1958, the "World Bridge Federation was founded to promote bridge worldwide, coordinate periodic revision to the Laws (each ten years, next in 2017) and conduct world championships.
Bidding boxes and bidding screens
In tournaments, ""bidding boxes" are frequently used, as noted above. In top national and international events, ""bidding screens" are used. These are placed diagonally across the table, preventing partners from seeing each other during the game; often the screen is removed after the auction is complete.
Much of the complexity in bridge arises from the difficulty of arriving at a good final contract in the auction (or deciding to let the opponents declare the contract). This is a difficult problem: the two players in a partnership must try to communicate enough information about their hands to arrive at a makeable contract, but the information they can exchange is restricted – information may be passed only by the calls made and later by the cards played, not by other means; in addition, the agreed-upon meaning of each call and play must be available to the opponents.
Since a partnership that has freedom to bid gradually at leisure can exchange more information, and since a partnership that can interfere with the opponents' bidding (as by raising the bidding level rapidly) can cause difficulties for their opponents, bidding systems are both informational and strategic. It is this mixture of information exchange and evaluation, deduction, and tactics that is at the heart of bidding in bridge.
A number of basic "rules of thumb in bridge bidding and play are summarized as "bridge maxims.
Bidding systems and conventions
A bidding system is a set of partnership agreements on the meanings of bids. A partnership's bidding system is usually made up of a core system, modified and complemented by specific "conventions (optional customizations incorporated into the main system for handling specific bidding situations) which are pre-chosen between the partners prior to play. The line between a well-known convention and a part of a system is not always clear-cut: some bidding systems include specified conventions by default. Bidding systems can be divided into mainly natural systems such as "Acol and "Standard American, and mainly artificial systems such as the "Precision Club and "Polish Club.
Calls are usually considered to be either natural or conventional (artificial). A natural call carries a meaning that reflects the call; a natural bid intuitively showing hand or suit strength based on the level or suit of the bid, and a natural double expressing that the player believes that the opposing partnership will not make their contract. By contrast, a conventional (artificial) call offers and/or asks for information by means of pre-agreed coded interpretations, in which some calls convey very specific information or requests that are not part of the natural meaning of the call. Thus in response to 4NT, a 'natural' bid of 5♦ would state a preference towards a diamond suit or a desire to play the contract in 5 diamonds, whereas if the partners have agreed to use the common "Blackwood convention, a bid of 5♦ in the same situation would say nothing about the diamond suit, but tell the partner that the hand in question contains exactly one ace.
Conventions are valuable in bridge because of the need to pass information beyond a simple like or dislike of a particular suit, and because the limited bidding space can be used more efficiently by adopting a conventional (artificial) meaning for a given call where a natural meaning would have less utility, because the information it would convey is not valuable or because the desire to convey that information would arise only rarely. The conventional meaning conveys more useful (or more frequently useful) information. There are a very large number of conventions from which players can choose; many books have been written detailing bidding conventions. Well-known conventions include "Stayman (to ask the opening 1NT bidder to show any four-card major suit, "Jacoby transfers (a request by (usually) the weak hand for the partner to bid a particular suit first, and therefore to become the declarer), and the "Blackwood convention (to ask for information on the number of aces and kings held, used in slam bidding situations).
The term "preempt refers to a high-level tactical bid by a weak hand, relying upon a very long suit rather than high cards for tricks. Preemptive bids serve a double purpose – they allow players to indicate they are bidding on the basis of a long suit in an otherwise weak hand, which is important information to share, and they also consume substantial bidding space which prevents a possibly strong opposing pair from exchanging information on their cards. Several systems include the use of opening bids or other early bids with weak hands including long (usually six to eight card) suits at the 2, 3 or even 4 or 5 levels as preempts.
Basic natural systems
As a rule, a natural suit bid indicates a holding of at least four (or more, depending on the situation and the system) cards in that suit as an opening bid, or a lesser number when supporting partner; a natural NT bid indicates a balanced hand.
Most systems use a count of "high card points as the basic evaluation of the strength of a hand, refining this by reference to shape and distribution if appropriate. In the most commonly used point count system, aces are counted as 4 points, kings as 3, queens as 2, and jacks as 1 point; therefore, the deck contains 40 points. In addition, the distribution of the cards in a hand into suits may also contribute to the strength of a hand and be counted as "distribution points. A better than average hand, containing 12 or 13 points, is usually considered sufficient to open the bidding, i.e., to make the first bid in the auction. A combination of two such hands (i.e., 25 or 26 points shared between partners) is often sufficient for a partnership to bid, and generally to make, game in a "major suit or notrump (more are usually needed for a "minor suit game, as the level is higher).
In natural systems, a 1NT opening bid usually reflects a hand that has a relatively balanced shape (usually between two and four (or less often five) cards in each suit) and a sharply limited number of high card points, usually somewhere between 12 and 18 – the most common ranges use a span of exactly three points, (e.g., 12-14, 15-17 or 16-18), but some systems use a four-point range, usually 15-18.
Opening bids of three or higher are preemptive bids, i.e., bids made with weak hands that especially favor a particular suit, opened at a high level in order to define the hand's value quickly and to frustrate the opposition. For example, a hand of ♠ KQJ9872 ♥ 7 ♦ 42 ♣ 763 would be a candidate for an opening bid of 3♠, designed to make it difficult for the opposing team to bid and find their "optimum contract even if they have the bulk of the points, as it is nearly valueless unless spades are trumps, it contains good enough spades that the penalty for being set should not be higher than the value of an opponent game, and the high card weakness makes it more likely that the opponents have enough strength to make game themselves.
Openings at the 2 level are either unusually strong (2NT, natural, and 2♣, artificial) or preemptive, depending on the system. Unusually strong bids communicate an especially high number of points (normally 20 or more) or a high trick-taking potential (normally 8 or more).
Opening bids at the one level are made with hands containing 12–13 points or more and which are not suitable for one of the preceding bids. Using "Standard American with "5-card majors, opening hearts or spades usually promises a 5-card suit. Partnerships who agree to play 5-card majors open a "minor suit with 4-card majors and then bid their "major suit at the next opportunity. This means that an opening bid of 1♣ or 1♦ will sometimes be made with only 3 cards in that suit.
Doubles are sometimes given conventional meanings in otherwise mostly natural systems. A natural, or penalty double, is one used to try to gain extra points when the defenders are confident of setting (defeating) the contract. The most common example of a conventional double is the "takeout double of a low-level suit bid, implying support for the unbid suits or the unbid major suits and asking partner to choose one of them.
Variations on the basic themes
Bidding systems depart from these basic ideas in varying degrees. "Standard American, for instance, is a collection of conventions designed to bolster the accuracy and power of these basic ideas, while Precision Club is a system that uses the 1♣ opening bid for all or almost all strong hands (but sets the threshold for "strong" rather lower than most other systems – usually 16 high card points) and may include other artificial calls to handle other situations (but it may contain natural calls as well). Many experts today use a system called "2/1 game forcing (enunciated as two over one game forcing), which amongst other features adds some complexity to the treatment of the one notrump response as used in "Standard American. In the UK, "Acol is the most common system; its main features are a weak one notrump opening with 12-14 high card points and several variations for 2-level openings.
There are also a variety of advanced techniques used for hand evaluation. The most basic is "the Milton Work point count, (the 4-3-2-1 system detailed above) but this is sometimes modified in various ways, or either augmented or replaced by other approaches such as "losing trick count, "honor point count, "law of total tricks, or "Zar Points.
Common conventions and variations within natural systems include:
- Point count required for 1 NT opening bid ('mini' 10-12, 'weak' 12-14, 'strong' 15-17 or 16-18)
- Whether an opening bid of 1♥ and 1♠ requires a minimum of 4 or 5 cards in the suit (4 or 5 card majors)
- Whether 1♣ (and sometimes 1♦) is 'natural' or 'suspect' (also called 'phoney' or 'short'), signifying an opening hand lacking a notable heart or spade suit
- Whether opening bids at the two level are 'strong' (20+ points) or '"weak' (i.e., pre-emptive with a 6 card suit). (Note: an "opening bid of 2♣ is usually played in otherwise natural systems as conventional, signifying any exceptionally strong hand)
- "Blackwood (either the original version or "Roman Key Card)
- "Stayman (together with Blackwood, described as "the two most famous conventions in Bridge".)
- Whether the partnership will play "Jacoby transfers (bids of 2♦ and 2♥ over 1NT or 3♦ and 3♥ over 2NT respectively require the 1NT or 2NT bidder to rebid 2♥ and 2♠ or 3♥ and 3♠), minor suit transfers (bids of 2♠ and either 2NT or 3♣ over 1NT respectively require the 1NT bidder to bid 3♣ and 3♦) and Texas transfers (bids of 4♦ and 4♥ respectively require the 1NT, or 2NT bidder to rebid 4♥ and 4♠)
- What types of "cue bids (e.g. rebidding the opponents' suit) the partnership will play, if any.
- Whether doubling a contract at the 1, 2 and sometimes higher levels signifies a belief that the opponents' contract will fail and a desire to raise the stakes (a penalty double), or an indication of strength but no biddable suit coupled with a request that partner bid something (a "takeout double).
- Whether doubling or overcalling over opponents' 1NT is natural or conventional. Most common artificial agreement is "Cappelletti, where 2♣ is a transfer to be passed or corrected to a major, 2♦ means both majors and a major shows that suit plus a minor.
- How the partnership's bidding practices will be varied if their opponents intervene or compete.
- Which (if any) bids are "forcing and require a response.
Within play, it is also commonly agreed what systems of opening leads, signals and discards will be played:
- Conventions for the "opening lead govern how the first card to be played will be chosen and what it will mean,
- "Signals indicate how cards played within a suit are chosen – for example, playing a noticeably high card when this would not be expected can signal encouragement to continue playing the suit, and a low card can signal discouragement and a desire for partner to choose some other suit. (Some partnerships use "reverse" signals, meaning that a noticeably high card discourages that suit and a noticeably low card encourages that suit, thus not "wasting" a potentially useful intermediate card in the suit of interest.)
- "Discards cover the situation when a defender cannot follow suit and therefore has free choice what card to play or throw away. In such circumstances the thrown-away card can be used to indicate some aspect of the hand, or a desire for a specific suit to be played.
- Count signals cover the situation when a defender is following suit (usually to a suit that the declarer has led). In such circumstances the order in which a defender plays his spot cards will indicate whether an even or odd number of cards was originally held in that suit. This can help the other defender count out the entire original distribution of the cards in that suit. It is sometimes critical to know this when defending.
- "Suit preference signals cover the situation where a defender is returning a suit which will be ruffed by his partner. If he plays a high card he is showing an entry in the higher side suit and vice versa. There are some other situations where this tool may be used.
- "Surrogate signals cover the situation when it is critical to show length in a side suit and it will be too late if defenders wait till that suit is played. Then, the play in the first declarer played suit is a count signal regarding the critical suit and not the trump suit itself. In fact, any signal made about a suit in another suit might be called as such.
Advanced bidding techniques
Every call (including "pass", also sometimes called "no bid") serves two purposes. It confirms or passes some information to a partner, and also denies by implication any other kind of hand which would have tended to support an alternative call. For example, a bid of 2NT immediately after partner's 1NT not only shows a balanced hand of a certain point range, but also would almost always deny possession of a five-card major suit (otherwise the player would have bid it) or even a four card major suit (in that case, the player would probably have used the "Stayman convention).
Likewise, in some partnerships the bid of 2♥ in the sequence 1NT - 2♣ - 2♦ - 2♥ between partners (opponents passing throughout) explicitly shows five hearts but also confirms four cards in spades: the bidder must hold at least five hearts to make it worth looking for a heart fit after 2♦ denied a four card major, and with at least five hearts, a Stayman bid must have been justified by having exactly four spades, the other major (since Stayman (as used by this partnership) is not useful with anything except a four card major suit). Thus an astute partner can read much more than the surface meaning into the bidding. Alternatively, many partnerships play this same bidding sequence as "Crawling Stayman" by which the responder shows a weak hand (less than eight high card points) with shortness in diamonds but at least four hearts and four spades; the opening bidder may correct to spades if that appears to be the better contract.
The situations detailed here are extremely simple examples; many instances of advanced bidding involve specific agreements related to very specific situations and subtle inferences regarding entire sequences of calls.
"Terence Reese, a prolific author of bridge books, points out["citation needed] that there are only four ways of taking a trick by force, two of which are very easy:
- playing a high card that no one else can beat
- trumping an opponent's high card
- establishing long suits (the last cards in a suit will take tricks if the opponents don't have the suit and are unable to trump)
- playing for the opponents' high cards to be in a particular position (if their ace is to the right of your king, your king may be able to take a trick, especially if, when that suit is led, the player to your right has to play their card before you do)
Nearly all trick-taking techniques in bridge can be reduced to one of these four methods. The optimum play of the cards can require much thought and experience and is the subject of whole books on bridge.
The cards are dealt as shown in the bridge hand "diagram; North is the dealer and starts the auction which proceeds as shown in the bidding table.
South in 4♥
|♥||J 8 7 4|
|♦||A 10 7 6 5|
|♠||K Q 8 7 2||
|♠||10 9 5 4|
|♥||A 2||♥||9 6|
|♦||J 4 2||♦||K Q 9|
|♣||10 7 2||♣||K 9 6 4|
|Lead: ♠ K||♠||A 6|
|♥||K Q 10 5 3|
|♣||A J 8 5|
As neither North nor East have sufficient strength to open the bidding, they each pass, denying such strength. South, next in turn, opens with the bid of 1♥, which denotes a reasonable heart suit (at least 4 or 5 cards long, depending on the "bidding system) and at least 12 "high card points. On this hand, South has 14 high card points. West "overcalls with 1♠, since he has a long spade suit of reasonable quality and 10 high card points (an overcall can be made on a hand that is not quite strong enough for an opening bid). North supports partner's suit with 2♥, showing heart support and about 6-8 points. East supports spades with 2♠. South inserts a "game try of 3♣, inviting the partner to bid the game of 4♥ with good club support and overall values. North complies, as North is at the higher end of the range for his 2♥ bid, and has a fourth trump (the 2♥ bid promised only three), and the doubleton queen of clubs to fit with partner's strength there. (North could instead have bid 3♥, indicating not enough strength for game, asking South to pass and so play 3♥.)
In the auction, North-South are trying to investigate whether their cards are sufficient to make a game (nine tricks at notrump, ten tricks in hearts or spades, 11 tricks in clubs or diamonds), which yields bonus points if bid and made. East-West are competing in spades, hoping to play a contract in spades at a low level. 4♥ is the final contract, 10 tricks being required for N-S to make with hearts as trump.
South is the declarer, having been first to bid hearts, and the player to South's left, West, has to choose the first card in the play, known as the opening lead. West chooses the spade king because spades is the suit the partnership has shown strength in, and because they have agreed that when they hold two touching honors (or adjacent honors) they will play the higher one first. West plays the card face down, to give their partner and the declarer (but not dummy) a chance to ask any last questions about the bidding or to object if they believe West is not the correct hand to lead. After that, North's cards are laid on the table and North becomes dummy, as both the North and South hands will be controlled by the declarer. West turns the lead card face up, and the declarer studies the two hands to make a plan for the play. On this hand, the trump ace, a spade, and a diamond trick must be lost, so declarer must not lose a trick in clubs.
If the ♣K is held by West, South will find it very hard to prevent it making a trick (unless West leads a club). However, there is an almost-equal chance that it is held by East, in which case it can be 'trapped' against the ace, and will be beaten, using a tactic known as a "finesse.
After considering the cards, the declarer directs dummy (North) to play a small spade. East plays low (small card) and South takes the ♠A, gaining the lead. (South may also elect to "duck, but for the purpose of this example, let us assume South wins the ♠A at trick 1). South proceeds by drawing trump, leading the ♥K. West decides there is no benefit to holding back, and so wins the trick with the ace, and then cashes the ♠Q. For fear of conceding a "ruff and discard, West plays the ♦2 instead of another spade. Declarer plays low from the table, and East scores the ♦Q. Not having anything better to do, East returns the remaining trump, taken in South's hand. The trumps now accounted for, South can now execute the finesse, perhaps trapping the king as planned. South enters the dummy (i.e. wins a trick in the dummy's hand) by leading a low diamond, using dummy's ♦A to win the trick, and leads the ♣Q from dummy to the next trick. East covers the queen with the king, and South takes the trick with the ace, and proceeds by cashing the remaining master ♣J. (If East doesn't play the king, then South will play a low club from South's hand and the queen will win anyway, this being the essence of the finesse). The game is now safe: South "ruffs a small club with a dummy's trump, then ruffs a diamond in hand for an entry back, and ruffs the last club in dummy (sometimes described as a "crossruff). Finally, South claims the remaining tricks by showing his or her hand, as it now contains only high trumps and there's no need to play the hand out to prove they are all winners.
(The trick-by-trick notation used above can be also expressed in tabular form, but a textual explanation is usually preferred in practice, for reader's convenience. Plays of small cards or discards are often omitted from such a description, unless they were important for the outcome).
North-South score the required 10 tricks, and their opponents take the remaining three. The contract is fulfilled, and North enters the pair numbers, the contract, and the score of +420 for the winning side (North is in charge of bookkeeping in duplicate tournaments) on the "traveling sheet. North asks East to check the score entered on the traveller. All players return their own cards to the board, and the next deal is played.
On the prior hand, it is quite possible that the ♣K is held by West. For example, by swapping the ♣K and ♥A between the defending hands. Then the 4♥ contract would fail by one trick (unless West had led a club early in the play). However the failure of the contract would not mean that 4♥ is a bad contract on this hand. The contract depends on the club finesse working, or a mis-defense. The bonus points awarded for making a game contract far outweigh the penalty for going one off, so it is best strategy in the long run to bid game contracts such as this one.
Similarly, there is a minuscule chance that the ♣K is in the west hand, but the west hand has no other clubs. In that case, declarer can succeed by simply cashing the ♣A, felling the ♣K and setting up the ♣Q as a winner. However the chance of this is far lower than the simple chance of approximately 50% that East started with the ♣K. Therefore, the superior percentage play is to take the club finesse, as described above.
After many years of little progress, "computer bridge made great progress at the end of the 20th century. In 1996, the American Contract Bridge League (ACBL) initiated official World Championships Computer Bridge, to be held annually along with a major bridge event. The first Computer Bridge Championship took place in 1997 at the North American Bridge Championships in "Albuquerque, New Mexico.
Strong bridge playing programs such as Jack (World Champion in 2001, 2002, 2003, 2004, 2006 and 2009), Wbridge5 (World Champion in 2005, 2007 and 2008), RoboBridge and many-time finalist Bridge Baron, would probably rank among the top few thousand human pairs worldwide. A series of articles published in 2005 and 2006 in the Dutch bridge magazine "IMP describes matches between Jack and seven top Dutch pairs. A total of 196 boards were played. Overall, the program Jack lost, but by a small margin (359 versus 385 imps).
There are several free and subscription-based services available for playing bridge on the "internet. For example:
- OKbridge is the oldest of the still-running internet bridge services: was established as a commercial enterprise in 1994, but the program started to be used interactively in August 1990 on players of all standards. Beginners to world class may be found playing there. OKbridge is a subscription-based club, with services such as customer support and ethics reviews.
- SWAN Games was founded April, 2000. In March 2004, announced a partnership to provide internet services to SBF members and is a competitor in subscription-based online bridge clubs.
- "Bridge Base Online (BBO) is the most active online bridge club in the world, with more than 100 000 daily connections and 500 000 hands played each day. in part because it is free to play regular games and volunteer-run tournaments.
These and other sites offer various features, such as opportunities to earn ACBL masterpoints, to play in online tournaments, to compile lists of friends, and to earn money playing Bridge. Bridge Base Online also has a "Vugraph feature showing tournaments from around the world for anyone interested to watch live. As well as written commentaries from top level players, voice commentaries have been incorporated since mid-2011. Software and hardware has been tested in 2011 in order to have digital cameras recognize the cards being played, which will avoid human error or delay.
Some national contract bridge organizations now offer online bridge play to their members, including the English Bridge Union, the "Dutch Bridge Federation and the Australian Bridge Federation. MSN and Yahoo! Games have several online rubber bridge rooms. In 2001, World Bridge Federation issued a special edition of the lawbook adapted for internet and other electronic forms of the game.
Advantages of online play include:
- The software prevents improper plays and calls, such as insufficient bids, "revokes (failure to follow suit when able), and actions out of turn.
- Unauthorised information cannot be passed by "tone of voice or "body language (but can much more easily be passed by external communication).
- Detailed records are kept which can aid partners to review and improve their bidding and play.
- Hands can be easily be analysed for best play (double dummy) afterwards.
- Can play with partners far away - or across town.
- No need to assemble 4 people in one place.
- Faster play - no shifting chairs or waiting for shuffles.
- Player rating systems may attempt to measure ability without regard to the number of games played or the number of years spent accumulating "masterpoints.
- Fewer restrictions on the conventions that are permitted compared to club tourneys.
- Easy to find opponents for practice in bidding and playing.
- You will meet bridge players from every country and time zone.
- Flexibility when to play (24/7), and choice of opponent skill level.
- Choice of individual, pairs, or team competitions.
- Fun to watch famous bridge stars play "live" as well as well-known personalities such as Bill Gates and Warren Buffett (who used to appear regularly on OKBridge in set games)
There are also a number of disadvantages:
- Inability to decide on bidding convention ahead of time when partners are strangers.
- A reduced social element.
- Players may leave before a hand finishes, or in the middle of a planned session, either intentionally or because of connection difficulties.
Tournaments are usually shorter online. A common length is 12 boards(deals). Online services support many simultaneous tournaments. When you finish one tournament, another will start soon.
Some online services like BBO have apps for Android and iPhone.
- e.g., if North is the dealer, they make a call, then the auction continues with East, South, West, and so on.
- e.g., if player A bids 2♥ and player B, their partner, raises to 4♥ and that becomes the final contract, then player A becomes declarer.
- e.g., if the declaring side makes a contract of 4NT and takes exactly ten tricks, fulfilling the contract (6 + 4), they receive 40 points for the first odd trick, and 90 (30 × 3) points for the remaining odd tricks, adding up to 130 contract points. If the contract was doubled or redoubled, the declaring side receives 260 and 520 points respectively. Additional bonuses may apply depending on the variation played: for example, in duplicate bridge, the declaring side is awarded a game bonus for receiving 100 or more contract points, which is 500 if vulnerable, for a total of 630 points (500 + 130); or 300 if not vulnerable, for a total of 430 points (300 + 130).
- "Reese, Terence (1980). Bridge. Teach Yourself Books. Hodder and Stoughton. "ISBN "0-340-32438-4., page 1.
- In face-to-face games, a convenient table size is from 32 to 40 inches (80 to 100 centimeters) square   or a round table allowing each player to reach to the center of the table during the play of the cards. In online computer play, players from anywhere in the world sit at a virtual table.
- "USATODAY.com - Billionaires bank on bridge to trump poker". usatoday.com. Retrieved 29 March 2016.
- "At the Bridge Table, Clues to a Lucid Old Age". The New York Times. 22 May 2009. Retrieved 29 March 2016.
- The terms deal, hand and board may be used interchangeably in bridge literature. More accurately, a "hand is one player's holding of 13 cards, a "deal is the four hands in one allocation of 52 cards; a "board is a term more applicable to duplicate bridge and refers to a deal.
- "Kantar, Eddie (2006). Bridge for Dummies, 2nd Edition. Wiley Publishing, Inc. "ISBN "978-0-471-92426-5., page 11.
- "historical change - Etymology of "bridge" (the card game) - English Language & Usage Stack Exchange". stackexchange.com. Retrieved 29 March 2016.
- Laws of Rubber Bridge, Law 44, pp. 20–21.
- Laws of Rubber Bridge, Law 1, p. 3.
- Laws of Rubber Bridge, Law 3, pp. 3–4.
- Gibson 1974, pp. 632–636.
- Laws of Rubber Bridge, Law 72(a), pp. 34–35.
- Laws of Rubber Bridge, Law 19, p. 10.
- Laws of Rubber Bridge, Law 18, p. 10.
- Laws of Rubber Bridge, Law 22, p. 11.
- Gibson 1974, p. 135.
- Laws of Rubber Bridge, Law 81, pp. 37–39
- Laws of Rubber Bridge, Law 41, p. 19
- Gibson 1974, p. 134.
- Laws of Rubber Bridge, Law 8, pp. 5–6.
- Laws of Duplicate Bridge, Law 6, pp. 9–10.
- Laws of Duplicate Bridge, Law 7, p. 11.
- Laws of Duplicate Bridge, p. 136: "The ACBL Board of Directors authorizes tournament organizers in ACBL sanctioned events to use bidding boxes."
- Laws of Duplicate Bridge, Law 80, pp. 99–100.
- Laws of Rubber Bridge, Law 4, p. 4.
- Laws of Duplicate Bridge, Law 6B & 6E, pp. 9–10.
- Laws of Duplicate Bridge, Law 7B & 7C, p. 11.
- Gibson 1974, pp. 135–136.
- Laws of Rubber Bridge, Law 40, pp. 18–19.
- Laws of Rubber Bridge, Part I ("Definitions"): Declarer.
- Gibson 1974, pp. 136–137.
- Laws of Rubber Bridge, Law 43, p. 20.
- Laws of Rubber Bridge, Law 68–71, p. 32–34.
- Laws of Rubber Bridge, Law 68–71, p. 82–86.
- Gibson 1974, p. 138.
- Laws of Duplicate Bridge, Law 2, p. 6.
- Laws of Rubber Bridge, Law 72–74, pp. 34–35.
- Laws of Duplicate Bridge, Law 77, p. 95.
- "World Bridge Federation Laws of Duplicate Bridge". Worldbridge.org. Retrieved 2011-11-05.
- ACBL Laws of Duplicate Bridge, 2008. Requirements for convention charts, alerts, and other laws are also available at the ACBL website.
- ACBL Laws of Contract Bridge, 2003.
- A cross-referenced listing including documentation is available at the BridgeHands website.
- Laws of Contract Bridge, ACBL official site.
- World Bridge Federation Laws of Electronic Bridge, 2001 for online play.
- "Alternate source for Biritch, or Russian Whist by John Collinson, 1886". Pagat.com. Retrieved 2011-11-05.
- Depaulis, Thierry; Fuchs, Jac (Sep–Oct 2003). First Steps of Bridge in the West: Collinson's 'Biritch'. The Playing-Card, Vol. 32, No. 2.pp. 67-76.
- (Elwell 1905 and Benedict 1900)
- (Melrose 1901)
- (Foster 1889)
- Turning Tricks – The rise and fall of contract bridge" The New Yorker, September 17, 2007
- "Review of the Olympic programme and the recommendations on the programme of the games of the XXIX Olympiad, Beijing 2008; page 8" (PDF). October 2011.
- Francis et al. 2001, p. 576. See WORLD BRIDGE FEDERATION (WBF).
- Bridge Lessons series, Stayman & Transfer (Deal 1), by Andrew Robson
- Taken from Andrew Robson Bridge Lessons series, "Stayman & Transfer", deal 14
- "RoboBridge". RoboBridge. 2011-10-22. Retrieved 2011-11-05.
- "Bridge Online Play Bridge Game On Line - OKbridge". okbridge.com. Retrieved 29 March 2016.
- Manley et al. (2011), p. 597
- "Online Bridge". swangames.com. Retrieved 29 March 2016.
- "Kantar, Eddie (2012). Bridge for Dummies (3rd ed.). "John Wiley & Sons. "ISBN "978-1-118-24083-0.
- Francis, Henry G., Editor-in-Chief; "Truscott, Alan F., Executive Editor; Francis, Dorthy A., Editor, Sixth Edition (2001). "The Official Encyclopedia of Bridge (6th ed.). Memphis, TN: American Contract Bridge League. "ISBN "0-943855-44-6. "OCLC 49606900.
- Manley, Brent, Editor; "Horton, Mark, Co-Editor; Greenberg-Yarbro, Tracey, Co-Editor; "Rigal, Barry, Co-Editor (2011). "The Official Encyclopedia of Bridge (7th ed.). Horn Lake, MS: American Contract Bridge League. "ISBN "978-0-939460-99-1.
- "American Contract Bridge League (2016). "Laws of Duplicate Bridge" (PDF). "Horn Lake, MS.
- "American Contract Bridge League (2014). "Laws of Rubber Bridge" (PDF). "Horn Lake, MS.
- Gibson, Walter B. (1974). Hoyle's Modern Encyclopedia of Card Games: Rules of All the Basic Games and Popular Variations. "Garden City, NY: Dolphin Books. "ISBN "978-0385076807.
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