CONFI stands for Controls Fit. It was devised by Dr. George Rosenkranz to bid slams with two balanced hands.
(reference: Bridge World Magazine, January 1975).
A balanced hand is defined as either 4333, 4432, 5332 or even 5422 shape.
There are 12 controls in a deck. An ace equals two, a king equals one. To search for a slam, the two balanced hands must have at least 10 controls between them. The expected minimum number of controls for balanced hands are given below:
0-6 HCP is 0 Controls, 7-9 HCP is 0 Controls, 10-12 HCP is 1 Control, 13-14 HCP is 2 Controls, 15-16 HCP is 3 Controls, 17-18 HCP is 4 Controls, 19-20 HCP is 5 Controls, 21-22 HCP is 6 Controls, 23-24 HCP is 7 Controls, 25-26 HCP is 8 Controls, 27-28 HCP is 9 Controls, 29-30 HCP is 10 Controls
1. After opener or responder makes a limited NT bid, the cheapest "meaningless" bid starts CONFI.
2. The first duty of the NT bidder is to tell the partnership how many controls they have. This is done in steps.
NOTE that with two or less controls than expected opener should demote their hand to the lower range.
3a. If opener does not show a minimum, and there are enough controls (10+) for slam, responder bids a biddable suit (at least four to the A, K, Q) up the line. With support, opener raises. Without, support, opener bids a biddable suit if they have one, or else bids NT.
If responder does not have a biddable suit, or there are not enough controls for slam, they bid NT. NOTE that if opener or responder later bids a suit that they have bypassed, this shows that the suit was unbiddable the first time (poor quality, or rarely, a three carder).
Also, rebidding a suit shows a five carder.
3b. If opener shows a minimum, responder can bid the cheapest NT (or pass if opener's response was in NT) to stop the slam try, if there are not enough controls for slam.
3c. If opener shows a minimum, responder can bid a biddable suit (at least four to A, K or Q) up the line. With less than the minimum number of controls, opener bids NT again to warn responder. With more than a minimum number of controls, opener bids as in (3a). NOTE that a NT rebid by opener can show either less than a minimum number of controls or no biddable suits.
4. Assuming that a 2NT opening equals a balanced 21-22. The responses are
This leaves 3 as the CONFI. Assume that after the sequence 2 - 2 - 2NT (23-24) or 3NT (25-27) also have the same structures.
Opener AKJx QJxx KJ AQJ
Responder xxx xx AQxx Kxxx
2NT | Pass | 3* | Pass |
3NT** | Pass | Pass*** |
* optimistic CONFI, **minimum number of controls 6 (or 5), ***Pass (no longer optimistic)
Opener AKJx Kxxx KJ AQJ
Responder xxx xx AQxx Kxxx
2NT | Pass | 3 | Pass |
4* | Pass | 4** | Pass |
4** | Pass | 5*** | Pass |
5NT**** | Pass | 6NT |
* 2nd step = 7 controls, ** showing a biddable suit up-the-line, *** (showing another biddable suit, but denying four hearts and spades (could have 5 diamonds), **** 5NT (no other biddable suit -- since responder denied spades)
Opener AKx AKxx Kxx Kxx
Responder Jx xx Jxxx AQJTx
2NT* | Pass | 3 | Pass |
4** | Pass | 5*** | Pass |
5*** | Pass | 6NT |
* with 2 extra controls, it's best to upgrade the hand from 19-20 to 21-22, ** 3rd step = 8 controls, ***only biddable suit
NOTE that the semi-solid club suit makes NT more attractive than 6
Opener AKxx AKx KQTx Kx
Responder Qxx xxx Jxxx AQx
2NT | Pass | 3 | Pass |
4* | Pass | 4NT** | Pass |
5*** | Pass | 6 |
* 3rd step = 8 controls, ** no biddable suit, ***first biddable suit.
NOTE that 6NT depends on a 3-3 spade break, whereas 6 is cold.
Opener KQxx AK AQx AKxx
Responder Jxxx xxx KJxx xx
2 | Pass | 2 | Pass |
3NT* | Pass | 4** | Pass |
5*** | Pass | 5**** | Pass |
5**** | Pass | 6 |
* 3NT (balanced 25-27), ** CONFI, *** 2nd step = 9 controls, ****first biddable suit