Joseph Caldwell

503 Chastine Drive, Spartanburg, SC 29301 USA

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4 October 2012


The game of modern contract bridge evolved in the early twentieth century (1920s).  Modern bidding systems are based on calculation of points that show the relative strength of hands, both in terms of individual cards (high-card points, or “Milton Work” points) and distribution (numbers of cards in suits).  Point-count bidding systems were developed in the United States and England.  The system developed in the US by Charles Goren and others was known as the “Standard American” or “Goren” system.  In the British Commonwealth, the major bidding system in use over the years and today is “Acol” (named after the Acol Bridge Club, formerly on Acol Road, London, where it began). 


Determination of the suit and size of a contract and which side will play it is decided by an “auction,” or “bidding.”  The early part of the auction is concerned mainly with communication of information about the suit holdings of the partners, and the latter part is concerned with establishing (defining, winning) the contract.  The early Standard American and Acol bidding systems were relatively simple and “natural,” that is, most individual bids could be taken at “face value” in describing the major features of a hand or the suits of a hand; for example, a bid of two clubs generally indicated that the bidder’s hand contained some clubs.  Over time, a number of bidding “artificial” bidding conventions were developed, such as nonpenalty doubles (1912), Blackwood (1933) and Stayman (1935).  The bids of these conventions are “artificial” in the sense that a particular suit bid may not directly reflect the representation of that suit in the hand, but instead may be used for communicating information about the hand in general, such as how many aces it contains.  The early conventions were relatively simple and few in number, and they did not alter the natural character of the Standard American and Acol systems very much.  Eventually, however, the conventions added to the Standard American system became so numerous and complex that the bidding lost much of its natural character.


In addition to the natural aspect, bidding systems are also characterized by the way in which they require mandatory bids from partners, or are “forcing.”  In an “approach forcing” system, whether a bid is forcing depends on the previous bidding (or “approach” to the current bid).  By contrast, in a “level forcing” system, whether a bid is forcing depends on the level of the bid (such as a “two-over-one-game-forcing” system). 


The bidding systems now in widespread use in the US have evolved to the point where they can no longer be characterized as natural.  To be sure, many natural bids remain, but the overall systems are now very complicated, replete with artificial bids to the point that their complexity now represents a substantial deterrent to many people who might wish to play.


The attached sheet presents a simplified natural bridge bidding system.  It is intended to help new players quickly learn a basic bidding system that will enable them to proceed to play bridge without investing a substantial amount of effort in learning a complicated bidding system involving many artificial bids and requiring the memorization of many bidding rules based on high-card points and suit lengths.  This system may (optionally) include several artificial (conventional) bids (Blackwood, transfers, and nonpenalty doubles).  It is similar to the Standard American and Acol systems, but substantially simplified.


Because of its simplicity, it cannot be reasonably expected that this bidding system will outperform complex systems with respect to reaching the best contract.  This system requires substantially less memorization of rules, however, enabling the new player to proceed much more quickly to enjoying the play of the hand, with reasonable results.  Instead of requiring a several-hundred-page book to describe it, it can be summarized on a single sheet.  The bidding systems now in widespread use in the US are difficult to learn, and playing them well requires substantial skill.  In general, better results are obtained by playing a basic system well than an advanced system poorly.


It is interesting to note that over the past century, the play of the hand has changed very little.  It is only the bidding that has evolved to a high degree of complexity.


In the US, the bridge community has been shrinking in recent years.  There are a variety of reasons for this decline, but one of them is certainly the complexity of modern bidding systems.  The game of bridge has much to offer.  It is hoped that this simplified system will lower the formidable barrier that bidding has become, and encourage new players to take up and enjoy the game.


Good luck!


Joseph Caldwell


© 2012 Joseph Caldwell.  All rights reserved.

Joseph Caldwell Bridge Bidding System

Version 1.02, 4 October 2012.  Posted at Internet website

© 2012 Joseph George Caldwell, All Rights Reserved


Balanced hands: 4333, 4432, 5332.                                                 Ranking of suits: spades, hearts, diamonds, clubs.

Major suits: spades, hearts; minor suits: diamonds, clubs.          Honor cards: AKQJ10.

Suit high-card-point (HCP) value: AKQJ = 4321.                                             Stopper: A; Kx; Qxx; Jxxx.

Hand value = sum of suit values.                                                       Suit length (L): number of cards in suit.

Biddable suit: A previously unbid suit, L>=5, or L>=4 with 2 honors.  (The symbol “>” means “is greater than”, and the symbol “>=” means “is greater than or equal to”.)

Rebiddable suit: A previously bid suit, L>=5 with 2 honors.

Suit support: First round: L>=5, or L>=4 with 2 honors; Second round: L>=3, if partner suggests L>=5.

Strong suit support: L>=5 with 2 honors.


The following table is used to guide the opening bid and closing bids after a suit fit has been found, or no-trump decided.  When using the bidding table, estimate the partner’s hand value as the midpoint of the point range indicated by his bids.  As the bidding progresses, adjust the estimated value as appropriate (e.g., if partner rebids a suit or bids a new suit).  The following table and bidding guidelines assume that there is no interference (bidding) from the opposition.  If interference occurs, it may not be possible to make the bids suggested by the table or guidelines.  In such cases, make a close bid (if possible) or pass.


Bidding Table

No Trump (NT) (balanced hand)

Suit (unbalanced hand)

Hand Value (combined hands, estimated)


Hand Value (combined hands, estimated)


37+ (grand slam)

7 NT

37+ (grand slam)

7 of suit

33-36 (slam)

6 NT

33-36 (slam)

6 of suit

25-32 (game)

3 NT

29-32 (minor), L>=9 in suit (game)

5 of suit


2 NT

25-32 (major), L>=8 in suit (game)

4 of suit

16-20  for opener, 12-20 for responder

1 NT

21-24, L>=7 in suit

3 of suit



17-20, L>=6 in suit

2 of suit



12-16, L>=5 in suit

1 of suit


Although this system may be used without artificial conventions, it is recommended that the following conventions be used after the player has mastered the non-convention system and play of the hand.  They are relatively easy to learn and are very useful.  They replace some natural bids with artificial ones, but mainly (except for Blackwood) at low levels of bidding, before a potential contract has been identified.  Initially, the new player need not use any conventions.

(1)     Standard Blackwood: To ask about aces, in deciding on slam, by bidding 4NT.  Forcing.  Response: 5 clubs for 0 or 4 aces; 5 diamonds for 1 or 3 aces; 5 hearts for 2 aces.

(2)     Transfers (in response to a 1NT bid from partner and a pass by the right-hand opponent (RHO); used by a weak hand to find a fit in a major suit, or to prevent a stronger hand from being exposed as the dummy):

(a)     (“Stayman”) Bid of 2 clubs (over 1NT, 3 clubs over 2NT).  If no biddable 5-card suit, asks partner to bid a 4-card major suit.  Forcing.  Promises 4 cards in one major suit, no 4333 distribution, and sufficient strength to continue bidding after partner’s response (8+ HCP for 1NT, 5+HCP for 2NT). Response of diamonds indicates none; response of hearts indicates hearts; response of spades indicates spades.

(b)     (“Jacoby Transfer”) Bid of 2 diamonds.  Forcing.  Promises 5 or more hearts.  Asks partner to bid 2 hearts.

(c)      (“Jacoby Transfer”) Bid of 2 hearts.  Forcing.  Promises 5 or more spades.  Asks partner to bid 2 spades.

(3)     Non-penalty doubles (informative doubles, takeout doubles, negative doubles):

(a)     (“Takeout Double”) If partner has not opened, and no biddable 5-card suit.  Forcing.  Asks partner to bid his best unbid suit (or NT for a balanced hand).  Shows opening hand (12 HCP) and 3-card support in unbid suits.  Partner jump-bids to show strong hand.

(b)     (“Negative Double”) If partner has opened (i.e., after an overcall by the opponents), and hand is too weak for a free bid.  Forcing.  Promises length (L>=4) in unbid major suit(s).


Bidding Guidelines:



16+ HCP:

Balanced hand: bid NT per table.

Unbalanced hand: bid biddable suit per table.

12-15 HCP: bid biddable suit (prefer major, L>=5) per table.

If insufficient hand for the preceding and the RHO has bid, may consider nonpenalty (“takeout”) double, if appropriate.

Otherwise, pass.



Respond to convention bids (nonpenalty double) per convention, as appropriate.

To a NT bid:

Balanced hand: Assess combined value of hands (add own-hand value to estimated hand value represented by opener), and bid NT per table (or pass).

Unbalanced hand (exploratory bidding):

If >= 6 HCP:

10+ HCP: jump-bid biddable suit (prefer major, L>=5).  Not forcing.

6-9 HCP: bid biddable suit (prefer major, L>=5).

If no biddable suit, consider transfer bid or (if RHO has bid) nonpenalty double, if appropriate.

If < 6 HCP: pass (or consider transfer bid or (if RHO has bid) nonpenalty double, if appropriate).

To a suit bid (exploratory bidding):

If >=6 HCP:

10+ HCP and strong suit support: raise 2.  Not forcing.

6-9 HCP and suit support: raise 1.

With no suit support: bid (new) biddable suit (prefer major, L>=5); if no (new) biddable suit, bid NT, per table.

If <6 HCP: pass (or (if RHO has bid) nonpenalty double, if appropriate).


Rebid by opener

Respond to convention bids (transfer bid or nonpenalty double) per convention, as applicable.

Assess combined value of hands.

If estimated HCP>=33, may use Blackwood convention to decide on slam.

If opened NT and was supported in NT, bid NT per table (or pass).

If opened suit and received support (same-suit response), bid suit per table (or pass).

If opened suit and received NT (a weak) response, bid new biddable suit or rebiddable suit or (if none) NT per table (or pass).

If opened NT and received suit response, or if opened a suit and received different-suit response, continue exploratory bidding:

With suit support: raise 1

With strong suit support: raise 2.  Not forcing.

With no suit support: bid new biddable suit (prefer major, L>=5) or rebiddable suit or (if none), NT, per table.  Do not pass.


Rebid by responder (and subsequent bids)

Respond to convention bids (e.g., Blackwood), per convention, as applicable. 

A hand “fit” occurs when a bid suit or NT is supported by partner.  If a fit has not yet been found, continue exploratory bidding as above (“Responder” or “Rebid by opener”) with rebiddable or new biddable suits or NT, but do not use jump bids (to keep the bidding levels low).  If a suit fit is found, bid that suit per table (or 4NT to ask about aces, if estimated HCP >=33).  If fit is not found, bid NT per table (or 4NT to ask about aces, if estimated HCP >=33). 


ACBL Convention Card: General Approach: Natural (Joseph Caldwell); Simple Overcall: 6-20 HCP; Jump Overcall: Strong; Opening Preempts Double is Takeout; Slam Conventions: 4NT Blackwood; Leads: as indicated in bold; Notrump Opening Bids: 1NT: 17-20; 2NT: 21-24; Stayman (if played): 2 clubs; Jacoby Transfer (if played): 2 diamonds is transfer to hearts; 2 hearts is transfer to spades; Major Opening Expected Min. Length: 4 in all positions; Minor Opening: 4 for both clubs and diamonds; 2-bids: all 17-20 HCP, 2NT response to 2-bids is nonforcing (NF).