[blml] Insufficient rebid

[Eric Landau]

At 04:00 AM 10/26/06, Matthias wrote:

>richard.hills at immi.gov.au schrieb:
> > You and your partner have agreed to play a
> > weak notrump and the lebensohl convention.
> >
> > Matchpoint pairs, South dealer, none vul.
> >
> > You, South, hold:
> >
> > Q63
> > 93
> > KJ53
> > AK87
> >
> > The bidding has gone:
> >
> > WEST      NORTH     EAST      SOUTH
> > ---       ---       ---       1NT
> > 1H        1S        Pass      ?
> >
> > What call do you make?
> >
>
>2S
>
> > What other calls do you consider making?
>
>None, but....
>It seems to me that I may be under different sets of UI restrictions if
>a) partner bids 1S without a care in the world or b) the TD is summoned,
>the options and the consequences are explained and partner now bids 1S.
>If partner seems to have missed (or misread, written bidding?) my 1NT ,
>I may have UI because of systemic information from 1 minor - 1H - 1S
>showing 5+ (for example). If, on the other hand, partner knew what he
>was dealing with he may well have only 4 spades (John`s two-suiter is a
>different logical explanation), since this is the hand type he cannot
>get across if no negative double of 2H is available (if he has limited
>values, with a stronger hand he has a cue available). Since partner will
>have a 4+card minor most of the time (if holding only 4 spades) a bid of
>2C seems suggested (certainly debatable whether 2C is a LA at
>matchpoints). Is this AI or UI? I think it is AI, but I am not
>completely sure.
>
>At matchpoints I would always bid 2S. If partner now bids 3 of a minor
>(probably John`s two-suiter) I raise the minor.

Matthias raises an interesting point.  My original reply to Richard 
assumed that partner deliberately chose to condone West's insufficient 
bid and bid over it.  But it is also quite possible that he has 
mistaken the auction, and doesn't realize that there has been an 
insufficient bid.

Clearly, if the table action suggests the latter, that is UI, and one 
is obligated to presume the former in choosing one's subsequent 
calls.  But what about the opposite case, where it is clear from the 
table action that partner is attempting to send some message by making 
a fortuitously available but undefined call?

If one has information from an extraneous source that partner does 
indeed know what the auction is, can that knowledge properly be treated 
as unauthorized for L16 purposes?

FWIW, I would think not.


Eric Landau                     ehaa at starpower.net
1107 Dale Drive                 (301) 608-0347
Silver Spring MD 20910-1607