The origin of this conventional defense method is unknown. The designation is also Acol Two No Trump, Acol 2 No Trump, Acol 2 NT, and variations thereof. This defense method held a certain popularity in the early stages of the evolution of the game in the United Kingdom, and it is only presumed that this defense method was devised in the bridge club in London on Acol road, for which the bidding system was named, to show a two-suited holding of game forcing strength. Source: bcmcIV.
The practice of opening the auction with a bid of No Trump with a range of 12-14 high card points has always been quite popular among bridge players, who favor the Acol bidding system. The definition of a No Trump opening is sometimes questionable since there is neither an exact guideline nor an established distributional pattern. The question of the state of vulnerability is also commonplace in deciding to open No Trump, and thus the range of the No Trump bid has become variable.
Foundation of the Concept
In general, the idea is to open the bidding auction with a holding containing values between 12 and 14 high card points. The object is to obstruct the opponents in the case that the major remainder of the values are in the possession of the opponents, who are then forced to commence competing on the two level. Allowed are distributional patterns containing a 5-car suit, and even a 6-card Minor suit. A No Trump opening on a distribution pattern of 2-5-3-3, with 5 Hearts is permissible, acceptable, and recommended. However, if the 5-card Major suit is Spades, then the preference is to open the Spade suit rather than bid No Trump.
The Acol 2 No Trump overcall can be either an immediate overcall after a normally weak No Trump of 12-14 range or in the balancing seat after two consecutive passes. This intervening bid is game forcing and partner may not pass before game is reached. The holding shown below is textbook for such an overcall.
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Intervenor |
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Meaning |
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| 1 NT |
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Range is 12-14 high card points. |
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Double |
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A double is always for penalty. Partner must pass. This penalty double strongly indicates a holding of at least 20 high card points or more. As a result the other two players each hold an average of 4 high card points. |
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2 NT |
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Acol 2 No Trump promising a strong two-suited holding, neither of which are known. |
Continuances
The advancer, in case the partner of the No Trump bidder passes, must bid a 4-card suit up the line, meaning that the advancer should not bid a 5-card suit before the 4-card suit. The partnership is already on the three level and bidding space should be consumed for the stronger hand to name and identify the two long suits.
If the advancer holds:
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Advancer |
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Advancer |
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3  |
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3  |
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3 |
The auction would continue until the advancer has been made aware of the two suits held by the intervenor. It is preferable to give support for the Major suit, if a Major suit is specified, even with less support than for the Minor suit, if specified, and greater support owing to the number of tricks necessary to make game. It is also quite possible that the advancer declares if the better fit is bid first by the advancer.
In general, such an Acol 2 No Trump overcall is game forcing even if the better fit is a Minor suit. If the better fit is discovered to be in a Minor suit, then the partnership must determine and agree whether or not the Acol 2 No Trump overcall is indeed game forcing to a game contract in this Minor suit and/or whether to explore game in a possible No Trump contract.
If you wish to include this feature, or any other feature, of the game of bridge in your partnership agreement, then please make certain that the concept is understood by both partners. Be aware whether or not the feature is alertable or not and whether an announcement should or must be made. Check with the governing body and/or the bridge district and/or the bridge unit prior to the game to establish the guidelines applied. Please include the particular feature on your convention card in order that your opponents are also aware of this feature during the bidding process, since this information must be made known to them according to the Laws of Duplicate Contract Bridge. We do not always include the procedure regarding Alerts and/or Announcements, since these regulations are changed and revised during time by the governing body. It is our intention only to present the information as concisely and as accurately as possible.