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Bridge: The UK Acol bidding style

This guide should help online players trying to play 'Acol' or 'Benji Acol' with a pickup partner.

Unfortunately there is no 'Standard Acol' system and its 4 card major, weak 1NT chassis gets much modified. Acol is pretty 'flexible! I have tried to lay out the broad principles, and include some popular variants you might agree as you sit down.

My notes here are for experienced players. As of summer 2005 Britain's EBU have a draft "standard Acol" pdf on their site, but it's not all that friendly. I have also drawn from Warwick University's (sometimes idiosyncratic) club Acol

Acol came from London's old Acol Road bridge club. So "ACOL" is quite wrong!

Acol summary

Responding to
one of a Suit


Weak No Trump

Opening 2 level:
- Standard Acol
- Benjamin style


Slam Bidding


Play conventions


General Acol Structure

  • Acol is a style of bidding as much as a complete system, and is very flexible. Hallmarks are being able to open 4 card majors, light openings, a weak 1NT (12-14) and "Strong Twos". Acol is fast and flexible: excellent for MP pairs
  • You should try to express your hand naturally, and to get in a notrump or suit limit bid as soon as practicable. Generally you should plan your next bid before commiting to the present one. Listen to partner..
  • All systems have strong calls to limit simple openings: Acol has two! 2C is a game force (or 2D in "Benji") but it retains an old-fashioned strong two = 'a hand of quality and power'. Not quite GF, this shows 8+ 'playing' tricks if a major, or 8½+ in a minor.
    Examples of Strong Two:    SKQJ963 H92 DAK5 CAJ   and   SAHAK1062 DK10 CAJ975
    The first example is a classic Acol 2S. On the second hand you might open 2H (forcing), rebid clubs, and still stop in 3H. An 'Acol two' is about 2 tricks lighter than a SAYC 2C. A 20-22 2NT is also available.

  • Opening light With big hands well taken care of, Acol's one level openings can safely be lighter than other systems. Players may open a mere 9 HCP with a good rebidable suit and 7 losers. If in doubt add HCP to the length of your two longest suits. eg "10hcp + 5 + 4". If this comes to 20+ always open. Many open "rule of" 19 or even 18! You might not approve - but this is what UK tournament players actually do!
    Example - 1S on:   SAQJ963 H92 DQ54 C84 = 1S rule of 18. 7 losers too strong for 2S
    or a 1H opening    S5 HAQ752 D104 CK8542 = rule of 19 (note: again a suit you'd want led)
    .. Of course such light openings have repercussions in later bidding development.
  • Acol's rules for one level are similar to other systems. With one or more 5+ card suits, open the longer, or higher ranking - natural bidding. A major may be bid with only 4 cards, but call longer suits first. Occasional 3 card minors with a very weak eg H9653 major won't be a disaster.
  • Four card majors With only 4 card suits you should open 1NT when in range and holding 4432 or 4333. Some players include 5 card majors in a 5332 1NT (especially hearts). otherwise:
    • 4333 simply call the 4 card suit and rebid in no trumps
    • 4432 non-touching has 2 options: open the major - rebid in NT, or the minor and bid up the line
    • 4432 touching majors opens 1H - (but 5-5 is still 1S, plan your rebids!)
    • 4432 touching with a minor - open the higher suit
    • Note that it is acceptable to open a 'tactical' major and rebid in no trumps to show range and balance. You will miss some minor fits but this is a common and effective pairs style, and typical Acol stuff!
    • 4441 open the suit immediately below the shortage except holding a singleton club when you open 1H (lower of touching majors). Middle of 3 touching is also used. Not playing 5cM is useful here!
Responding and development
  • When responding, bid 4 card suits up the line. Always plan your next bid. If you are only worth a single bid you should try to show any major held immediately, or consider raising partner on three
  • A bucket non forcing 1NT (5-9) response is common opposite 1H/S and may contain a weak long suit.
  • 2/1 responses promise 9+ points (8 with excellent suit). 2H is always 5 card. 2C/D show a 4+ suit. (2/1=10+ is becoming popular)
  • After a 2-over-1 response we can still pass out opener's simple suit rebid, or 2NT. Otherwise you should plan to call again.
  • Jump shift is strong 16+. It should be single suited, or good suit with support. With 2 suits you should plan to bid them out simply. Responder's new suit is forcing, except 2-any over opener's 1NT rebid.
  • Opener's change of suit simple rebid after 1/1 response is non-forcing, albeit seldom passed. Generally passing this shows less than 10 points and a singleton in the first suit. Give "false preference" on xx.
  • A reverse by opener is a 1 round force with 16+ points and at least 5-4 shape. The first suit will always be longer.
  • Responder's second round reverse is game forcing
  • Any new suit at the three level is forcing for one round -so generally to game
  • Fourth suit forcing simply means "bid again" and shows an interest in 3NT (but may yet be strong GF support)
  • Return to partners major after 4SF shows a power hand, GF, slam implications
  • Return to 3 of opener's major after a limit bid is forcing "choice of game" - 1H - 1S; 2NT - 3H (ditto if spades raised)
  • Acol's notrump ladder:rebid 1NT rebid 2NT rebid 3NT
    1 over 1 response 15-1617-18 19+
    2 over 1 response   15-16 17+
    With 12-14 balanced you simply open 1NT. 2NT is 20-22 (varies in "Benji")
Trying for game
  • Any possibly ambiguous bid shows values or length in that suit. Show stoppers rather than ask for stoppers.
  • Trial bids (say 1H - 2H - 3C*) show length 3+ in the strain with at least 2 losers there. Partner is asked for help.
  • Acol players often call no-trumps rather than raise a minor - especially at pairs
  • Calls of 2NT/3NT after 1M - 2M raises show 4cM and are natural. Used to avoid 4-3 fits
  • A simple raise of responder's 2-over-1 is invitational, usually 4 card support. It can be passed!
  • Stayman is part of Acol, but may be "garbage" escape from weak 1NT rather than promising 4 card major. Regard pickup partner's new suit after using Stayman as a one round force (agreements vary)
Slam zone
  • A new suit at the 4 level is a cue and suggests slam interest.
  • Generally any cue promises 1st round control - ace or void
  • A jump or voluntary raise to 4 of a minor is GF and suggests slam interest.
  • Simple Blackwood can be assumed to be "on" and is now Acol default.
  • Gerber is only "on" in Britain by prior agreement
"Modern" (1975+) Acol variants - you should explicitly agree these!
  • Red suit transfers "RST" are very common over any NT, but must be agreed. Default is new suit = weak takeout!
  • A 12-16 1NT rebid and "Crowhurst" 2C range/majors enquiry is common
  • Most modern players use Stayman over 2NT too. But trad Acol default is 3C "Baron" bid suits upwards (yuk)!
  • Roman key card Blackwood is popular. Default responses "3041": 5C=0/3 5D=1/4 5H=2 5S=2+trump queen (sometimes extended)
  • Splinters are commonly played as jumps to 4C or 4D opposite 1M. They may be extended eg to any unnecessary jump in an advanced partnership. But don't try this at pickup - nor major splinters!

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