Efos Opening Bids

The Economical Forcing System was used in international championships by leading Swedish players such as Mr. Jan Wohlin, Mr. Nils Olaf Lilliehook, and Mr. Gunnar Anulf. The concept is reported to have originated with Mr. Eric Jannersten. The idea behind the concept is to give the opener the most opportunity to make the most accurate and descriptive rebid, in order to describe his holding. As a result, most of the responses are artificial in meaning. The EFOS bidding system for the opening bid is based roughly on the ACOL system in that a 4-card Major suit can be opened first, and the use of a strong No Trump opening.

Below is a list of the opening bids:

1 :   13-21 high card points and a 3-card plus Club suit.
1 :   13-21 high card points and a 4-card plus Diamond suit.
1 :   13-21 high card points and a 4-card plus Heart suit.
1 :   13-12 high card points and a 4-card plus Spade suit.
1 NT:   16-19 high card points plus, balanced distribution.
2 :   22 plus high card points and a 5-card plus Club suit.
2 :   18 plus high card points and a 5-card plus Diamond suit.
2 :   18 plus high card points and a 5-card plus Heart suit.
2 :   18 plus high card points and a 5-card plus Spade suit.
2 NT:   22-23 high card points and balanced.

 

Efos and Extended Stayman

The Economical Forcing System also permits the partnership to discover a 4-4 and/or a 5-3 fit in the Major suits, and can be used to find a 4-4 and/or 5-3 fit in the Minor suits. This is possible only after a strong No Trump opening, indicating 16-19 high card points and a balanced holding. In general terms this is described as Extended Stayman. The rebids of the opener are as follows:
1 NT   2    
2       Shows no 4-card Major suit and a minimum opening of 15-16 high card points.
2       Shows a 4-card Heart suit and 15-18 high card points.
2       Shows a 4-card Spade suit and 15-18 high card points.
2 NT       Shows both 4-card Major suits and a minimum of 15-16 high card points.
3       Shows no 4-card Major suit and a maximum of 17-18 high card points.
3       Shows 2 Spades and 2 Hearts and a maximum of 17-18 high card points.
3       Shows a 5-card Heart suit, a 2-card Spade suit and 17-18 high card points.
3       Shows a 5-card Spade suit, a 2-card Heart suit and 17-18 high card points.
3 NT       Shows both 4-card Major suits and 17-18 high card points.
 

Following a 2 Diamond rebid by the opener, the responder can rebid 3 Clubs to ask for a 3-card Major suit:

1 NT   2    
2   3   Responder is asking for a 3-card Major suit.
3       Denies a 3-card Major suit; inference is 2-2 in the Major suits.
3       Shows a 3-card Heart suit.
3       Shows a 3-card Spade suit.
3 NT       Shows a 3-card suit in both Major suits.
 

If the opener rebids 3 Diamonds, showing 2-2 in both Major suits, the responder may request additional information about the holding in the Minor suits:

1 NT   2    
3     Opener shows a 2-2-4-5 distribution in the Minor suits.
  4   Responder is asking the opener for his better Minor suit.
Pass       Opener may pass with a 5-card Club suit and a minimum.
4       Opener shows a 5-card Diamond suit and a minimum.
5       Opener shows a 5-card Club suit and a maximum.
5       Opener shows a 5-card Diamond suit and a maximum.

The concept of EFOS introduced several modern treatments in the No Trump bidding, such as Repeated Stayman (or the Extensive Stayman Structure) and an extensive transfer system.

The information provided on this web page does not completely cover all aspects of this Economical Forcing System. After the opening of one of a suit, the nearest suit bid is either natural or a general forcing bid, which makes EFOS somewhat similar to a relay system. It must also be noted that if the first response to the opening bid is in the same suit as the opener, and only one level higher, then this suit raise signifies a strong bid indicating reversing values.

Efos Extended Stayman is a convention, which assists the partnership to determine Major and Minor suit fits. It must be entered on the Convention Card and explained to any opponent who wishes an explanation. Source: Dr. Klaus-Peter Wiese.

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.


email convention links
Claus and Raymond Conventions Bridge Sites
 
home back home
Home Page Glossary Home Page II
 
back   back
Response Methods   Glossary