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9: Acol Revision

Acol Revision

So far we have covered uncontested auctions (with a few sidetracks into competitive auction). It’s time to summarise what we know and begin to complete the EBU card downloadable as ebu20bA5 from

Philosophy 101: What is Acol? 

According to it is “An approach-forcing, natural bidding system, based on a weak NT and 4 card majors, popular in the United Kingdom and the Commonwealth.” Further, says “The Acol system is continually evolving but the underlying principle is to keep the bidding as natural as possible and preferring to bid a suit over notrump whenever possible.”

Evolving is right: you may find a few surviving older players who play a variable NT (strong NT when vulnerable). Also, a few people who attend Derek Patterson’s advanced lectures may play weak NT at any vulnerability except strong at third in hand,s till within an Acol structure. I don’t recommend either of these: the intellectual effort of having two different patterns of uncontested bidding is not worth the reduced risk of a penalty double and the reduced pre-emptive value: maybe worth considering if you play Bridge for money.

Acol isn’t 5-card Majors. When I play 5CM within an approach-forcing framework I write the card basic structure line as “5CM, big 2C, 3 wk 2’s”. Acol means that you never need to open a 2- or 3-card minor—a suit bid which might be a doubleton is alertable. In Acol, you can always call a spade a spade.

The wikipedia Acol article says: “Approach forcing... [means that] whether or not a bid is forcing (systemically requiring 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.” Translated: when responder names a new suit his partner (opener) must bid again. The unopposed sequence “1C” “1D” is forcing for one round. This helps responder who doesn’t need to leap around to get clarification but does mean opener must know what his second bid will be if he gets one: this can affect what the first bid is.

When responder wants to show a game forcing (perhaps slam-interested) hand he forces with an unnecessarily high bid, skipping a whole level as in “1D” “2H” or “1C” “2S”. This jump-shift established a force as far as 3NT or 4 (ie game unless the only fit is a minor). The jump-shift shows either a good side-suit and agreement for partner or a self-supporting suit playable opposite a weak doubleton; future bids show which.

If, while you are agreeing your card, a partner tells you you aren’t playing Acol, smile sweetly and agree. Write whatever pleases them on the EBU form. We will return to the form from time to time when we have more to add.


In the first box headed GENERAL DESCRIPTION OF bidding methods write ACOL. Important variations from someone else’s version of Acol appear in the next boxes on this page. There is nowhere to say we play a new suit as a one round force and a jump-shift as a (near) game force. These are part and parcel of Acol.

EBU20bA5 1nt openings and responses

We play a 12-14 NT throughout. Some, non-EBU cards have several spaces to write NT strength: I usually scrawl 12-14 across the lot of them. Because we may open 1NT on a good 11 or a bad 15 we need a footnote marker (1) and in the SUPPLEMENTARY DETAILS space write “(1) maybe good 11/bad 15”. Ignore the artificial and shape constraints options; we play usual. The possibility of the hand containing a weak or fair 5CM is unremarkable though obviously the opponents should be told if they ask even a vague question about shape. We should be 4333, 4432 or 5332 and maybe just possibly 5422.

In the “Responses” section:

  • 2C “promissory Stayman” (promissory just means we won’t bid 2C without at least one 4CM), as usual the responses are “2D” no 4CM, “2H” at least 4H does not deny 4S and “2S” at least 4S and not 4H;
  • 2D “transfer to H” aka Jacoby transfer, footnote (2) explains bounce and break;
  • 2H “transfer to S” aka Jacoby transfer, footnote (2) explains bounce and break;
  • 2S “transfer to C”, footnote (3) explains use of the intermediate bid (2NT);
  • 2NT “transfer to D”, footnote (3) explains use of the intermediate bid (3C);
  • 3 any suit-setting “GF, slam try” (perhaps AKxxxx, T86, A4, A2 hoping partner will show a H control)
  • 4C Gerber (which will be described in slam conventions)
  • 4 other non-invitational, possibly pre-emptive.

The range of a transfer could be anything from a bust to a slam try and that is the normal way to play this so it needs no written statement: as always explain if asked. It’s probably not a good idea to make a minor suit transfer on a 5-card suit and a bust. Safer to pass and hope 1NT isn’t doubled and run to 2D if it is.

We aren’t yet covering competitive auctions but it’s worth making an exception for the quite common double of a weak 1NT. This usually is for penalties and means a hand expecting 1NT to fail. As the NT-bidding is probably outgunned in HCP slam or even game are mere dreams and safety is the key. There are other possibilities, but the recommendation is that all responses after a penalty double of 1NT are natural: for example, “2C” is now to play. Bear in mind the double may be based on a running suit and an entry and the doubler may well not have a double of a suit.

EBU20bA5 TWO-LEVEL openings and responses 2C

2C is the big bid, 23+ balanced or 9 playing tricks in a substantial hand if unbalanced. Substantial means having some high cards: 11 cards to the QJ will play for 9 tricks but can not be opened 2C though 6 of your suit might be verging on pessimistic! Look at these hands I’m quoting from

1 KQ432




2 AQxxx




Don’t open 2C with either. (Actually people who play strong twos may have an even bigger problem! They too can’t open a strong two but partner can’t so easily visualise so many HCP after a 1-level opening.) That article distills the thinking into a rule “4 or fewer losers and 4 or more quick tricks”. Think 4x4. Losers are as in the LTC even though no suit has been agreed; QT are counted by suit AK=2, AQ=1.5, KQ or A=1, Kx=.5QT. (The Italians had a similar scheme, called controls, counting 2 for an A and one for a K: that's Mediterranean inflation for you.) Some more examples from the cited book:

  • AJ, KQJT762, AK4, 8. (4 losers and 4 quick tricks). Open 2 clubs.
  • AKQJ9874, 72, 65, A. Open 1 spade, only 4 losers, but just 3 quick tricks.
  • AKQT2, AKQJ2, 42. 8. Open 2 clubs, 3 losers and 4 quick tricks.
  • A, AQ643, K763, AKJ. Open 1 heart. 5 quick tricks, but at least 5 [4?] losers. Downgraded for the singleton A of spades. Aces that are not supported with other honors in the suit or are in short suits have diminished value. If you don’t have firm control of the trump suit, you also run the risk of a forcing defence in spades.
  • AKT54, AK5, AKT3, 8. Open 2 clubs. Any hand with 6+ quick tricks is too strong to open with 1 spade or 1 heart.

There is a wide range of possible structures for responses to 2C. The basic one has 2D as negative which I suggest means fewer than 3 “controls” or 1.5 QT as described above: ie not an A and a K. The logic behind this choice is that 2C hands may have slam potential and controls are the key to slams. 2H, 2S are hands with a 5CM and 3+ controls, 2NT is a hand with at least 8 HCP and no 5CM this includes hands with a 5C minor. I offer this structure as being easy to remember more like what you may already know and what partners are likely to expect. 

Personally, I prefer “2D” Waiting: a relay asking the opening bidder to further describe the strong hand. 2D may be strong (3+ controls) or weak <4 HCP: intermediate hands are shown by the other bids eg “2H” shows some points, few controls and a H suit. There is plenty of room for regular partners, with the inclination, to decide their preferences but remember, 2C are rare so specific responses are rarer. The default card will stick to the basics in the responses column: 

“2D <1.5QT, 2H/S ≤3QT, 2NT≥8HCP”. Higher responses are undefined. The card doesn’t ask for further developments but add a note (3) explaining that the sequence 2C 2D 3M is non-forcing.

EBU20bA5 TWO-LEVEL openings and responses

2D 2H 2S Preemptive in the named suit as discussed previously. You could write “6-card suit 5-10” and a note (4) “May be shaded 3rd in hand”.

Responses 2NT is a one-round force asking for a feature in a non-minimum hand. Write “2NT=feature?” on the card.

2NT “20-22 balanced may include singleton A” We haven’t discussed responses which should be as similar as possible to 1NT namely “3C: Stayman” “3D, 3H: Jacoby Transfer” We’ll discuss uses for 3S  later, meanwhile leave it idle. As the 2NT hand is much more likely to hold a good 5CM than a 1NT hand was, there is some point in using 3C, unlike Stayman over 1NT, to ask first for a 5CM. Again this is for further discussion. 

EBU20bA5 other opening bids

These are all the same, 10+ HCP, min length 4. We haven’t covered other responses yet so leave the rest blank. The ACOL on the title line covers the fact that new suits are a 1RF, JS is a game force, 1NT describes range rather than shape.

3 bids are as we described previously. 7+ card with little outside 5+ HCP. Note (4) applies.

4 bids are similarly preemptive but with greater offensive strength (so must be 7+ HCP) and typically an 8 card suit. Note (4) applies.

EBU20bA5 Slam conventions

“4NT=RKCB 30, 41, 2-Q, 2+Q” You don’t need to write down that the K of trumps is the fifth key card: anyone who knows how to read a convention card will already know. There is more to RKCB (including how to escape the treadmill) but it’s for the lessons not the convention card. 

“Gerber 4D=0, 4H=1, 4S=2, 4NT=3, 5C=4” You only use Gerber in 3 cases: openings of 1NT or 2NT or the sequence 1x 1y 1NT. Don’t use either slam convention (really slam-avoidance convention) if any plausible response takes you too high!

No bid above the level of 3NT has to be alerted and the advice not to ask about bids until the end of the auction applies here with special force. A reminder, you can only only ask when it’s your turn to bid: do only ask if you need to know to decide on your next bid (which will be infrequent).