The concept of Extended Gerber conventional method is a method of pinpointing certain key cards in slam bidding. The concept was devised by Mr. Jerold A. Fink of Cincinnati, Ohio, United States. This variation can be employed equally well after a No Trump contract has been bid or a trump suit has been established. His concept is, that after a trump suit has been established, a rebid by the opener of 4 Clubs is asking partner to show controls.

Fundamentals of the Concept

Note: The fundamental concept is based on the guideline that 1 Ace equals 2 controls and 1 King equals 1 control.

North		East		South		West		Meaning
1		Pass		3		Pass
4		Pass		4				Shows 0 or 1 control.
				4				Shows 2 controls.
				4				Shows 3 controls.
				4 NT				Shows 4 controls.

With 5 or more controls, the responder must subtract 5 and bid according to the above control-showing diagram. For example, the responder holds 3 Aces = 6 controls and 1 King = 1 control, then the responder has 7 controls. He subtracts 5 from 7, and the result is 2. The responder then bids 4 Hearts.

Alternative Response Method

A second alternative to show the number of controls and not use the subtraction scale is shown below:

4 :	Shows 0 or 1 control - or 5-6 controls - or 10-11 controls.
4 :	Shows 2 or 7 controls.
4 :	Shows 3 or 8 controls.
4 NT:	Shows 4 or 9 controls.

Whether or not this method has any additional advantages over the first alternative is a matter of partnership agreement.

Bidding Sequences as Examples

The following examples follow the first alternative with the subtraction scale. In most cases, the responder will bid 4 Diamonds showing 0 or 1 control. The opener can rebid 4 Hearts requesting the responder to clarify his holding.

Bidding Sequence 1
North		East		South		West		Meaning
1		Pass		3		Pass
4								Extended Gerber is initiated.
		Pass		4		Pass		Shows 0 or 1 control.
4								North inquires: Partner, do you hold zero controls or 1 control?
		Pass		4				The responder shows zero controls. (Note: Theoretically the responder could show 5 to 10 controls.)

Bidding Sequence 2
North		East		South		West		Meaning
1		Pass		3		Pass
4		Pass						Extended Gerber is initiated.
				4		Pass		Shows 0 or 1 control.
4								North inquires: Partner, do you hold zero controls or 1 control?
		Pass		4 NT				The responder shows one control. (Note: Theoretically the responder could show 6 to 11 controls.)

Any other rebids on the four level by the asking bidder are considered final sign-offs. The asking bidder can also sign-off by bidding 5 Clubs and simply passing the forced 5 Diamond response by the responder, or by bidding 5 Diamonds and passing the forced 5 Hearts response by the responder or simply correcting it to 5 Spades, the agreed trump suit.

King and Queen Inquiry

Once the information regarding the number of controls has been conveyed, the Extended Gerber bidder is able to inquire about the Kings and Queens in two specific suits. All four suits are divided in six groups of two suits each, and therefore there are six Asking Bids. They are:

Asking Bids	Intended Two Suits.
5 NT:	Both Major Suits - Spades and Hearts.
5 :	Both Pointed Suits - Spades and Diamonds.
5 :	Both Red Suits - Hearts and Diamonds.
5 followed by 5 :	Both Black Suits - Spades and Clubs.
5 followed by 5 :	Both Rounded Suits - Hearts and Clubs.
5 followed by 5 NT:	Both Minor Suits - Diamonds and Clubs.

The responder counts each King as equalling 2 points and each Queen as equalling 1 point in each of the intended two suits and responds in steps shown below:

1st Step:	Shows 0 points - no King or Queen in the intended suits.
2nd Step:	Shows 1 point - no King and 1 Queen in the intended suits.
3rd Step:	Shows 2 points - 1 King or 2 Queens in the intended suits.
4th Step:	Shows 3 points - 1 King and 1 Queen in the intended suits.
5th Step:	Shows 4 points - 2 Kings and no Queen or 1 King and 2 Queens in the intended suits.
6th Step:	Shows 5 points - 2 Kings and 1 Queen in the intended suits.
7th Step:	Shows 6 points - 3 Kings and no Queen or 2 Kings and 2 Queens in the intended suits.

 

 

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.