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! 2 is a game force (or 2 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:    KQJ963 92 AK5 AJ   and   AAK1062 K10 AJ975
  The first example is a classic Acol 2. On the second hand you might open 2 (forcing), rebid clubs, and still stop in 3. An 'Acol two' is about 2 tricks lighter than a SAYC 2. 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 - 1 on:   AQJ963 92 Q54 84 = 1 rule of 18. 7 losers too strong for 2S
  or a 1 opening    5 AQ752 104 K8542 = 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 9653 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 1 - (but 5-5 is still 1, 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 1 (lower of touching majors). Middle of 3 touching is also used. Not playing 5cM is useful here!

• 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" - 1 - 1; 2NT - 3 (ditto if spades raised)

• Acol's notrump ladder:	rebid 1NT	rebid 2NT	rebid 3NT
  1 over 1 response	15-16	17-18	19+
  2 over 1 response		15-16	17+

  With 12-14 balanced you simply open 1NT. 2NT is 20-22 (varies in "Benji")

• Any possibly ambiguous bid shows values or length in that suit. Show stoppers rather than ask for stoppers.
• Trial bids (say 1 - 2 - 3*) 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)

• 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

• 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" 2 range/majors enquiry is common
• Most modern players use Stayman over 2NT too. But trad Acol default is 3 "Baron" bid suits upwards (yuk)!
• Roman key card Blackwood is popular. Default responses "3041": 5=0/3 5=1/4 5=2 5=2+trump queen (sometimes extended)
• Splinters are commonly played as jumps to 4 or 4 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!