Jacoby 2NT MAJORS & Delayed Jacoby 2/3NT MAJORS

A jump response of 2NT to a 1-level opening in any major suit is always strong and forcing. This is the "Jacoby 2NT"-convention.

We distinguish between "major suit openings" (MaS), which are always real, and "minor suit openings" (MiS), which are always conventional.

The delayed Jacoby 2NT has been demonstrated by next tables. It appears that there exist only 6 ways, in which a major suit fit can be detected on 2-level, after a first real response in a major suit. All possible bidding series are written down in the tables below.
Table B:
This bidding series can never end up in a game contract. The responder is weak with a 4+card spades. With >=10 hcp's he would have done at least a limit raise. The opener is also weak, otherwise he would have opened 1NT at least, or have done SHiD+++ rebid.
Table D:
The opener doesn't have overvalue because he doesn't jump to game leven. Having 10-12 hcp's and know his partner's strength the responder still decides to ask for controls. His hand must have a very special distribution. It does do any harm, he will probably end up in 4©/ anyway.
Table F:
There is sufficient strength for a game in hearts or NT, but are these games possible? Any rebid may be understood as real. The opener has to choose: 3NT (all suits stopped), 4 (4,4+ in cub, diamond, no fit), 4/5 (6+ in diamonds, no fit), 4© (to play), 4 (4/5,4,4,1/0 short in clubs), of 4NT (Blackwood). There is no room left for control bidding.
Table G:
After applying the MaD+++ convention the opener observes the 4,4 fit. He already knew of his partner's 10 hcp's and of the other suit. So he must ask for controls. The responder was already aware of all this from the moment MaD was done. He was not permitted to jump, even if holds a strong hand. He must allow for bidding space to exchange controls. He should realize, that his partner must start this process on his next turn.
Tables: A, C, E:
There exist only these four bidding series which end up in the "delayed-2NT-Jacoby ". Please note that the delayed Jacoby 2(3)NT bid is made by East, so again the responder. So here, the trump suit having been established, the responder, who may have hidden strength, may ask for controls by bidding 2(3)NT.
  A               B             C       D       E       F       G    
west   east         west   east         west   east   west   east   west   east   west   east   west   east  
1   1©         1   1©         1   1   1   1© 1   1   1   3©/ ^    1   2/  
2©   2NT *       1   2         2   2NT *       1 2©/        2   2NT *         ?       2©/   3©/ *
    ?   3©/   3NT *        3NT *    
relay, belooft 2/3-kaart harten
5-card and 10-12 HCP's
^ 5-card and > 12 HCP's
* Sohl extra delayed Jacoby-2/3NT convention

The problems that occurred at D and F, lead to a situation where the fit only can be established by passing or repeating the suit on 3-level. Then the exchange of controls may start after that by calling a different suit. If there is no fit, you must look for some other contract.
There are no examples in the table of how the 3-5 fit after a club opening bid is found. This is done by means of the Joker convention. This leads to a similar situation as described above.

Sometimes this convention is called Truscott. I read this in Chris Niemeijer's book "BIEDERMEIER" about the dutch standard bidding system (derived from the British Acol), upon which 70 dutch top players agree according to polls held by Chris. The convention described above looks like a generalization of the Truscott-convention which is played after take out doubles. In MAF the convention is a little bit different.
A direct response of 2NT to a normal major suit opening is always, whether the opening call has been doubled or not has been doubled, very strong. In the USA this response is called the "Jacoby 2NT"-convention.
In case the major suit opening bid has been doubled we extend this convention with Alan Truscott's ideas. In MAF generally the meaning of of a response does not change after a double. The 2NT response on a 1-level-major suit opening however, is an exception on this rule. The response was forcing already and now the Truscott convention defines that the 2NT response is transformed in a multi-way call. Therefore you could call the convention, very applicably, Jumping Jacott Sohl. However we w'll not do so, because the convention has two names already, which is one to much already.
The 2NT response after a 'take out double' may have either of the next two meanings:

  1. the same meaning as described above with the Jacoby 2NT convention
  2. the 2NT response may also be done instead of a common limit raise in the opening suit, while through applying Truscott also is agreed that a direct 3-level call in the opening (major) suit always is preemptive. The opener's rebid (the cheapest control, so according the agreements made under a. !!) should never exceed the 3-level bid in the opening suit, in order to allow for a rebid of 3 in the opening suit, which now (after the take out double) has the meaning of a limit raise.

You may regret the the loss of the normal 2NT-response in Acol, which is done after a 1-level opening bid in a suit and a balanced hand of 10-11 hcp's without support in the opening suit. This bid however is not lost at all. All four Sohl responses allow for second responses of 2NT which all have the old Acol-denotation.

If you want to see examples of bridgames in which the matter, treated above, is practiced you should click on examples and choose for the appropriate convention or for any other typical call.