Acol

Acol is a bridge bidding system. It is named after a road in Hampstead, London, where there was a bridge club in which the system started to evolve in the 1930s. According to Terence Reese, its main devisers were Maurice Harrison-Gray, Jack Marx and S. J. Simon. [Terence Reese and David Bird, "Acol in the 90s", Robert Hale, 1990. See page 7 of the paperback edition, ISBN 0 7090 5379 7.] Marx himself, writing in the "Contract Bridge Journal" in December, 1952, said: "...the Acol system was pieced together by Skid Simon and myself the best part of 20 years ago." [Peter Hasenson, "British Bridge Almanack", 77 Publishing, 2004, ISBN 0-9549241-0-X, p54.] The first book on the system was written by Ben Cohen and Terence Reese. [Cohen, Ben and Terence Reese 1938. "The Acol system of contract bridge". Joiner & Steele, London.] Skid Simon explained the principles that lay behind the system, [Simon S.J. 1949. "Design for bidding". Nicholson & Watson, London.] and the system was further popularised in Britain by Iain Macleod. [Macleod, Ian 1952. "Bridge is an easy game". Falcon, London.] The Acol system is continually evolving but the underlying principle is to keep the bidding as natural as possible. It is common in the British Commonwealth but rarely played in America.

Bidding system structure

* Acol is a natural system: most opening bids, responses and rebids are made with at least 4 cards in the suit bid, whilst most no trump bids are made with balanced hands.
* It is a four-card major system: only four-card suits are required to open 1Spades or 1Hearts, unlike Standard American and many other systems where five-card suits are required.
* It is an "approach forcing system": whether or not a bid is forcing, i.e. systemically requires a response, depends on the previous bidding (approach). This is in contrast to "level forcing systems", such as 2-over-1, where the level of the bid determines whether or not it is forcing.
* Acol makes extensive use of limit bids: limit bids describe the hand so closely, in terms of high card points (HCP) and shape, that the one who makes the limit bid is expected to pass on the next round, unless partner makes a forcing bid.
* Understanding and correct use of limit bids and forcing bids is fundamental to applying the system: all no trump bids below the level of 4NT are limit bids as are all suit bids which merely repeat a suit already bid by the partnership; changes of suit may be forcing or not depending on the approach bids.
* The level of the 1 NT opening bid influences other bids: the normal choice is between a "weak no trump" (12-14 HCP) and a "strong no trump" (15-17 HCP).

Variants

Acol is an unregulated system. There is no Acol governing body and no single publication containing the "official" Acol (unlike, for example, Standard American Yellow Card). It can be compared to a living language since it is liable to change at the whim of users. The main versions of Acol in use today are:
* Acol: unregulated Acol, from the simple to the complex, remains in common use throughout the UK. At any one time the version in most common use will be known as "Standard Acol" although this term will mean different things to different players and is becoming increasingly confused with Standard English Acol.
* Standard English Acol (originally called simply "Standard English"). Developed by Sandra Landy under the auspices of the English Bridge Union (EBU), this variant was designed to facilitate the learning of bridge and to provide standardised guidance to novices, intermediate players and their teachers. This variant uses the weak 1NT opening (12-14 points). Simple conventions such as Stayman, Blackwood and Transfers are included at various stages in the learning process. It has been widely promulgated by the EBU and by EBUTA in particular, but the exact form is used mainly by those who have learned their bridge recently and those who taught them.
* Benjaminised (Benji) Acol: recognising that strong 2 opening bids are rarely used, the 2Hearts and 2Spades openings are used to show weak hands containing long suits (under 10 HCP and a 6-card suit). Very strong hands (8 playing tricks) are shown by an opening bid of 2Clubs which forces a 2Diams response allowing suits to be shown. The strongest hands (eg 23+ points or a game force hand) are shown by an opening bid of 2Diams.
* Reverse Benji: identical to Benji except that the 2Clubs and 2Diams bids are switched in meaning. A 2Clubs opening bid is now the strongest bid as in basic Acol.
* Acol with Three Weak Twos: this variant is similar to Reverse Benji Acol except that the strong 2Diams bid is abandoned in favour of a third weak two (in diamonds). Thus 2Clubs is the only strong bid in this system. Abandoning the extra grade of strong bid means that 'Acol two' style hands cause some problems, either having to be opened at the one level or forced into the 2Clubs bid.
* Acol with Multi 2Diams: this variant of Acol makes use of the Multi 2 diamonds convention. The 2Clubs bid is used as in standard Acol (23+ points). Various uses are made of the 2Hearts and 2Spades bids, with traditional strong twos or Lucas twos being some popular methods.

Standard Acol

The following is a brief summary of the Standard Acol of the early/mid 2000's.

Opening bids

Opening bids promise at least 12 high card points (HCP), or the equivalent in HCP and shape, unless preempting. Apart from NT, opening bids guarantee the ability to make a rebid over any forcing response from partner. There are six "special" opening bids which are quite closely defined, and one wide-ranging opening bid:

*Special opening bids:
**1 NT - Shows a balanced hand (4-3-3-3, 4-4-3-2 or 5-3-3-2). Subject to partnership agreement, it may be either weak (12-14 HCP), strong (15-17 or 16-18 HCP) or variable (i.e. varying between weak and strong according to vulnerability). Limit bid.
**2Clubs - Conventional game-forcing bid, promising game-going values (normally 23+ HCP) and at least 5 quick tricks. Game forcing unless responder replies 2Diams and opener rebids 2NT.
**2 of any other suit - Strong two bid which shows a strong hand with at least eight playing tricks and a 6-card suit (or two 5-card suits). Forcing for one round.
**2NT - Shows a balanced hand with 20-22 HCP. Limit bid.
**3 of a suit - Pre-emptive, normally seven or more cards in the suit bid (may be six at favourable vulnerability), weak hand (not more than 10 HCP). Not forcing.
**3NT - Pre-emptive, shows a long solid minor suit and is called the Gambling 3NT
*Wide-ranging opening bid (made if too strong to pass and unable to make one of the special opening bids):
**1 of a suit - Promises a minimum of 12 HCP and a 4-card suit, 11 HCP and a 5-card suit, or 10 HCP and a 6-card suit. Not forcing.

Responses to 1 of a suit

* pass - less than 6 HCP
* 2 of opener's suit - at least four-card support and 6-9 HCP. Limit bid.
* 3 of opener's suit - at least four-card support and 10-12 HCP. Invites game if opener has requisite strength (14 HCP or more). Limit bid.
* 4 of opener's suit - at least five-card support for opener's major and 6-10 HCP, this is pre-emptive and to play.
* 1 NT - 6-9 HCP, denies ability to bid at 2 level. Not necessarily balanced. Limit bid.
* 2 NT - balanced, 10-12 HCP. Limit bid.
* 3 NT - balanced, 12-15 HCP. Limit bid.
* 1 of a new suit - promises at least four cards in the suit bid, 6 HCP upwards. Forcing for one round.
* 2 of a new suit (below 2 of opener's suit) - normally 5-card suit, at least a good 8 or 9 HCP. Forcing for one round
* Jump in a new suit - 5-card suit (or support for partner), at least 16 HCP, Game force."note: these last three bids may conceal 4-card support for opener's suit, whereas the three NT responses deny 4-card support for opener"

Responses to 1 NT

* 2Clubs - Stayman. Opener responds 2Diams with no four-card major, 2Hearts with a four-card heart suit and 2Spades with four spades (denies four hearts). Forcing for one round.
* 2 of any other suit - weak takeout, opener must pass.
* 3 of a suit - shows a five-card suit, forcing for one round.
* 2NT - 11-12 HCP. invites game if opener is maximum (i.e. for a weak opening NT, if opener has 14 or a good 13 HCP).
* 3NT - to play.
* 4Clubs - asks for aces. (Gerber)
* 4Hearts, 4Spades - to play.
* 4NT - slam invitation, opener bids 6NT with a maximum.
* 5NT - slam invitation, opener bids 6NT unless a minimum. Note: some play as invitation to 7NT; opener bids 6NT if minimum, 7NT with a maximum).

Responses to 2 NT

* 3Clubs - Baron. Opener bids his lowest four-card suit. Forcing. (Stayman may also be used as in responses to 1NT, i.e. 3Diams shows no 4-card major).
* 3 of other suit - shows a five card suit, forcing to game.
* Other responses as over 1NT.

Responses to 2 Clubs

* 2Diams - negative. Responder lacks the strength for a positive response. Unless opener rebids 2NT (balanced, 23-24 HCP, which may be passed), the sequence is forcing to game.
* 2NT - fairly balanced, 8 or more HCP. Forcing to game.
* 2 of a suit - at least five in the suit, the equivalent of an ace and a king in high cards. Forcing to game.
* 3 of a suit - Solid suit of at least six cards. Forcing to game.

Responses to 2 of a suit

* 2NT - negative. Responder lacks the strength for a positive response.
* Simple bid of a new suit - 8 or more HCP, at least five in the suit. Forcing to game.
* 3 of opener's suit - 5-8 HCP, at least 3-card support. Forcing to game.
* 3NT - flat hand, 8-11 HCP. Not forcing.

Opener's suit rebid after one-level opening

"Rebid own suit"
* Rebid of own suit at lowest level - minimum hand, at least a five-card suit, 12-15 HCP, non-forcing.
* Jump rebid of own suit - strong hand, normally at least six-card suit, 15-19 HCP, non-forcing but highly invitational.

"Bid new suit"
* Bid of new suit at lower level than first suit - minimum hand, 12-15 HCP, first suit has at least as many cards as second suit, non-forcing.
* Bid of new suit at higher level than first suit but without jumping ("Reverse bid") - strong hand, 16-19 HCP, first suit has more cards (at least five) than second suit, forcing for one round.
* Jump in new suit - strong hand, 16-19 HCP, first suit has at least as many cards as second suit, forcing for one round.

"Support for responder"
* Simple raise of responder's suit - minimum hand, 4-card support, 12-15 HCP, non-forcing
* Jump raise of responder's suit - stronger hand, 4-card support, 16-18 HCP, non-forcing
* Jump to game in responder's suit - game values, 4-card support, 19 HCP, non-forcing

Opener's NT rebid after one-level opening

(The following bids assume a weak NT opening)

After suit response at one level the traditional rebids are:
* 1NT - balanced, 15-16 HCP, limit bid
* 2NT - balanced, 17-18 HCP, limit bid
* 3NT - balanced, 19 HCP, limit bid

However, the modern approach modifies the ranges for the rebids thus:
* 1NT - balanced, 15-17 HCP, limit bid
* 2NT - balanced, 18-19 HCP, limit bid
* 3NT - Often an Acol two type of hand prepared to play in NT.

After a suit response at two level the traditional rebids are:
* 2NT - balanced, 15-17 HCP, limit bid
* 3NT - balanced, 18-19 HCP, limit bid

The modern approach is to use the 2NT rebid as forcing and use 3NT as 15-17 with support for the minor that responder has bid (one option).

After the 2NT (forcing) rebid, either bid naturally or use an enquiry (3Clubs) to seek definition of the 2NT rebid.

Fourth suit forcing

A bid of the fourth suit at the 2 level by responder is a one-round force, usually asking opener to bid no trumps with a stopper in the fourth suit. A fourth suit bid at the 3 level is similar, but forcing to game.

References

* [http://www.ebu.co.uk/education/learning/landyfiles.htm Standard English Acol] (Described as a "dialect of Acol")
* Landy and EBU Committee. "Really Easy Bidding" 1998 The English Bridge Union, Aylesbury, UK, ISBN 0-9506279-2-5.