1 ¨ opening bid, responses and rebids etc.

In the previous chapters (i.e. those corresponding to the buttons above 1¨ in the menu frame) all hands are defined, with which you are not allowed to open 1¨, because you have to open something else.
All the next chapters deal with the description of extreme, i.e. not fitting in the 11-19 hcp interval, opening hands: In MAF with every hand containing 11 or more HCP's the auction must be opened.
Hence the remaining hands, i.e. those hands, not described in the chapters mentioned above, all must be opened with 1¨.

If your partner opens the auction with 1¨, all you know is:

Such cryptic descriptions of opening bids are very unusual in bridge. Yet, in MAF it is the only correct description of the 1¨ opening bid.
As a matter of fact, the proposition 'any bridge system, which does contain such a cryptic opening bid, is not properly defined" could be defended easily. The risk of forgotten hands and of ambiguities is always considerable. Both phenomena are bad. It's better to define all but one opening bid, and allocate the residue of the collection of opening hands to the remaining opening bid. Thus nothing is forgotten and the risk of ambiguities is smaller then.
The true meaning of this 1¨ opening bid must be deduced from the fore mentioned cryptic description, because MAF players must have a clear ideas about what kind of hands pertain to this opening bid.
If you want to see the result of the deduction, a traditional 1¨ diagram, now, you must click the previous hyperlink immediately.

We start this deduction now:
We distinguish between two categories, A: >=2 clubs and B: singleton or void in clubs. With our knowledge of the other opening bids following table can be set up.


 
PROPERTY CONSEQUENCES
distribution: strength:
A    
no 2/3 level opening <= 20 HCP's
no 1NT opening no balanced hand with 15-17 HCP's
no 1ª or © opening no 5-card ©/ª  
no 1§ a:   no balanced hand with 18-19 HCP's
no 1§ b: or c: no 5+card §  
no 1§ d: or e: no 4-card ©/ª
B    
no 2/3 level opening <= 20 HCP's
no 1ª or © opening no 5-card ©/ª  
no 1§ at all void/singleton in §
 


In the table above the consequences of not being able to open 2/3«, 1NT, 1ª, 1© or 1§ are collected and ordered.
After some trial and error you soon conclude that there are two categories of hands that must be opened with 1¨. These are described in the next table.


 
DISTRIBUTIONS and STRENGTHS of ¨ OPENING HANDS
  ª © ¨ § HCP's
A: <=3 <=3 >=3 <=4 11-14
B: <=4 <=4 >=4 <=1 11-19
 


The result is very promising. There appears to be only one distribution with less then four diamonds: The 4,3,3,3 distribution with 4 clubs. The (bridge league's) rules allow such hands to be opened with 1¨. The strong hands containing the singleton §, may be shown by recalling the 4-card major suit. Please note that these last hands nearly all become strong if you add the distributional values.



ETHIC INTERMEZZO Here at the diamond opening bid, many things are deduced through reasoning. This raises the question whether you have to tell the opponents about the conclusions drawn. Do they have a right to know this information? When you must alert the opponents? In a separate intermezzo you may read some philosophical thoughts about this. Anybody who interested should click now. There is a button over there to return here again.

The promised analyses are executed on a separate sheet. If you are interested you may read this. The most important matter, the result, is condensed in the next table.
The hands, having less then 15 HCP's and originally belonging to category B, have been shifted to category A. The remaining hands in B are all strong enough for reverse or limit bidding; this way of bidding automatically shows the short clubs, because there simply are no other 1¨-opening hands, which are that strong.


Deduced meaning of the 1¨ opening
calculated relative frequencies of occurrence of differently distributed hands*
category: A ** B ***
strength: 11-14 HCP's **** 15-19 HCP's
properties: maximum 3 in each major suit, 0 to 4 § void/singleton in §:
type: a: b: c: d: e:
length ¨-suit: 3 4 5+ 5+ 6+
distribution    
4,3,3,3 13.441 13.441  
4,4,3,2   18.452
5,3,3,2   20.047  
5,4,2,2 4.588
5,4,3,1 5.652 2.412  
6,3,2,2 7.425  
6,3,3,1 4.575 0.630
6,4,2,1 2.095 0.846  
6,4,3,0 0.601 0.233
7,2,2,2 0.691  
7,3,2,1 2.556 0.326
7,3,3,0 1.470 0.045
7,4,1,1 0.181 0.066  
7,4,2,0 0.168 0.060
total: 13.441 31.893 50.049 3.617 1.000
* the absolute frequency of the 1¨ opening is 5,67% which is 100% relatively  
** 85% of these A-hands contain at least one 3-card major suit
*** 78% of these B-hands contain a 4-card major suit
**** 57% has 11-12 and 43% has 13-14 HCP's


The relevant distributions and their relative frequencies of occurrence are shown in this table. This is done to complete the information. Of course all these data are not directly important for the bidding.

I am sorry, but I have to tell you that I recently discovered that the calculations I have made, comprise one or more mistakes. Nevertheless, for the moment I leave the results as they are. Within a few months the figures will be corrected, and these sentences will be removed.
The corrections will not cause great differences. The essential conclusions will not be affected.

Please note that only 13% of times a hand is opened with 1¨, it holds the 4,3,3,3 with 3 diamonds and 4 clubs.
The 1¨ opening appears to possess another remarkable property: more then the half of the possible opening hands contain at least 5 diamonds. If you play MAF, you will experience often that you have to open clubs, because of the 4-card major suit you possess; with the 4,4,3,2-distribution and a 4-card diamonds, this happens twice as much as when your second suit would have been clubs. This is the main cause of high frequency of the 5+card diamonds, or as a matter of fact the low frequency of the 4-card diamonds.

In the 1§ section it was promised that in this section should be explained, why mainly, it was not wise to open hands with 4 clubs (not containing a 4-card major suit) with 1§. The explanation can be given now.
All hands, containing 4, 5, 6 or 7 diamonds and as well as 4 clubs, would have to be opened with 1§. Now these hands must be opened with 1¨, which is much better for both minor suit openings.
Hands with 5-card in clubs are usually opened in clubs, even if the diamonds are longer. With certain strength/weakness opening with 2§,3§ or 3ª also must be considered. When you are interested to see an overview of all opening bids with 2-suited hands, you should click the last link.

With the knowledge we have gained until now it is possible to start building the 1¨ diagram, in which the relevant bidding agreements are condensed, just like it was done at the other opening bids.



when your screen resolution is not higher than 1024 x 768 pixels :
View the diagram "full screen" (in Netscape: 'open [frame] in new window' under the right mouse button.)

 
1¨ all other opening bids impossible,   pass weak, support in ¨, no 6-card « < 6
              forcing for a partner with less then 2 diamonds 1© Diamonds Sohl, always forcing >= 0
a: 4,3,3,3 distr. with 3-card ¨ 4-card § 11-14          p: 5+card © 2nd response: 1NT or pass MaD+ 6 - 9
b: 4-card ¨, no 4-card major suit or 5-card § 11-14     q: 5+card ©/ª 2nd response 2©/ª MaD+ 10-12
c: 5+card ¨, no 4-card major suit or 5-card § 11-14     r: 6+card « 2nd response 3« 0 - 9
d: 6+card ¨, no 4-card major suit or 5-card § 15-19     s: balanced 2nd response: 2NT 10-12
e: 4+card ¨, void/singleton §, 4-card major suit     15-19      t: exploring mysterious secret goals >=15
      
First rebid of the opener
1st response a: b: c: d: e:
1© sohl 1ª * 1ª * 1ª * 1ª * 1ª *
1ª 2ª 1NT/2ª,+ natural + 3/4ª wise
1NT pass pass pass/2¨ 2©/ª # 2/3¨ #
2NT WHIMS 2©/ª 2©/ª ©/ª 3/4©/ª # 3/4©/ª #
other ** wise wise wise wise wise
Second rebid of the opener, after 1ª relay to the sohl response
2nd response a: b: c: d: e:
p: 2©,+ pass/1NT/2©,+ 2¨/©/NT wise wise
q: 2©/ª,+ 2©/ª/NT,+ 2«/2NT,+ wise wise
r: pass pass pass pass pass
s: wise wise wise 3©/ª wise
t: 1NT 1NT 2¨ 2©/ª # 3¨ #
+ = MaD+ # = MaD+++   ** SHiCe or MaD
1ª 5+card ª, forcing >= 6
1NT no 5-card major, very little support in ¨ 6 - 9
2§ 5+card § ** >= 10
2¨ 5+card ¨ ** >= 10
2© fit in ¨, void/singleton ©, forcing SHiCe >= 12
2ª fit in ¨, void/singleton ª, forcing SHiCe >= 12
2NT 5,5 in majors WHIMS >= 8
3§ fit in ¨, void/singleton §, forcing SHiCe >= 12
3¨ 5+card ¨, invitation to 4/5¨ or 3NT ** >= 12
3© 5-card ©    MaD+ >= 13
 
type frequency %
absolute relative
a: 0.762 9.92
b: 1.918 24.98
c: 3.801 49.51
d: 0.417 5.44
e: 0.779 10.14
total: 7.677 100.00
  What is wise?

  wise is: the best possible natural and
  non forcing description of one's hand

 

  When does the opener rebid in §?

  only in case c: (5+card diamonds) and
  when the opener also possesses 4 clubs

3ª 5-card ª    MaD+ >= 13
 
   
* An opener's rebid of 1ª is a relay which shows support in hearts.
Only without support in hearts different rebids are allowed. With balanced hands this must be 1NT.
** No 5+card in any of the major suits
 © Chiel Verwoest  
                                  

return to : LINKS GENERAL OVERVIEWS


The diagram contains, just like you expected, nearly all data with respect to the diamond opening. Where it does not contain the data itself, you may find the appropriate links to detailed information. If you want to see examples, please make your choice on the example page.

 
If you arrived here because you wanted to read about the "sohl principle" then we give you the opportunity to link to various other paragraphs where remarks are made about "sohl":

1§-Sohl 1©-Sohl 1ª-Sohl 1NT-Sohl 2©/ª-Sohl 2NT-Sohl 3NT-Sohl
the SOHL overview

The Sohl response to 1¨ opening bid is, as you expected:: 1©. At diamonds we see a new phenomenon. The rebid here is a (hearts denying) relay (!!): 1ª-Sohl. This pecular construction enables the responder to show a weak 5-suiter in hearts, by reresponding 1NT (the Sohl was real). Calling 2© also show a 5-suiter in hearts, but the latter one in stronger.
After a first response of spades a similar distinction is made between weak and strong, but in that case there is no annoying Sohl in the bidding.
Als je geen steun hebt na een schoppen antwoord zeg je 1NT. Dit is een mooi contract om met zwakke handen te spelen. If you cannot support the spades then, having weak hands, 1NT may be a fine contract to play.
However the strong spades follows the bye pass, this does not disturb the bidding (and this remains unchanchanged by what you'll read after this).

At the diamond-Sohl the construction is turned around. The responder is the first one to describe his hand. The opener follows with his describing call. One situation exists on which this 'calling sequence' has to be turned back.
The opener must realize himself that he may be forced by the Sohl to call 2© te bieden. If he does'nt like this at all (singleton) he should refuse the 'relay'. He has to anticipate on possible happenings and he must deny hearts, by calling something else. By rebidding 1NT instead he does so, and he also shows a weak balanced opening hand. The similar call is used after a 1ª with a minimal balanced hand without spades.
There is even more. This is not in the diagram (no room, low frequency of occurrance, often 1NT is a fine contract). Having the singleton hearts, you could also show this by doing something natural on 2-level. This would also show a fine (~13 hcp's) unbalanced hand. 2§: 4,5+,1,3- -distribution in resp. clubs, diamonds, hearts and spades (e.g. 3- means <=3 cards); 2¨: 3-,6+,1-,3- -distribution and finally 2ª: 4-,4+,1-,4 -distribution.
All this very similar to the natural rebids on a 1ª response. With spade support, the opener would have called of course 2,3 of 4ª according to his strength.

Apart from the common meanings of the Sohl responses:the 10-12 sans atout, the weak 6-card and the mysterious hand, we meet some extra's here to show the strength of 5-cards in the major suits. You need these in order to end the bidding on a safe level incase of a fit. Further detail can be read from the diagram.

In the diagram you also encountered some new conventions. They look very familiar because the are identical or similar to those you read about in the club chapter. The bidding, these conventions in cluded are mainly targeted on achieving contracts in major suits and notrump.
The follow up bidding is only partially denoted in the diagram. If you know what kind of hands openers and Sohl responders might possess, you're on your way for the major part. The bidding runs all smooth and fine. Thinking along logical lines will bring you to the right contract easily.

SLOTWOORD
Finishing this chapter also finishes the description of the bridge bidding system MAF. The opening bids on the 2- and 3-levels are appicable in any other system. As to the 1NT opening bid this was true already for a long time. The major suit opening bids in MAF could also be used by any other 5-card major system.
MAF's kernel is constituted of the minor suit opening bids, together with the Sohl-concept of responding. The description could have been more extensive. I decided not to do so and to keep it concise. Now everybody can adapt MAF to her or his personal preferences and prejudices, and after that still persist they play MAF.



The introduction of the sohl responses makes the system very vulnerable to bidding disturbances by the opponents. The defense system contains agreements how to handle these disturbances. As to the subject of this page, you should have a look at overview DEFENSE after 1§/1¨ openings where most of the possible interventions are discussed shortly.




If you want to see examples op bridge games in which this chapter's theory is applied pleas click on examples klikken. Then you'll be send to a page where you're enabled to make your choice.