[blml] MI and Logical Alternatives

[Alain Gottcheiner]

At 15:39 5/04/2007 +1200, Wayne Burrows wrote:
> >From the NOT News at the Canberra Summer Festival of Bridge.
>
>#1 NWT Rd 1, Bd 3; 12 tricks, NS ­1370
>         AQ97
>         7543
>         3
>         9873
>KJ            2
>AQJ2        K986
>K9852      AQJT76
>Q5           AK
>         T86543
>         T
>         4
>         JT642
>Dealer S, Vul EW
>S   W   N   E
>P   1D  P   2D
>P   2H  P   3S
>P   4D  P   4NT
>P   5H  P   6D
>P   P    P
>
>There were no alerts. South had no possibility of describing the 6-5
>as all 2-suited options were constructive. South asserted that she
>would have bid 4S over 2D had she been aware that the opponents were
>using "inverted minors".
>Director rule score stands and NS appealed.
>The AC agreed that this particular South may have bid 4S but
>determined that it was not an action that would be given serious
>consideration by a significant proportion of experienced players in
>the field.
>-


AG : AFAIC this is not the main concern. If N/S use a very aggressive 
preempting style (which can be ascertained from their CC), you have to 
accept their claim, as the non-alert damaged *them*.

I don't know, however, whether a spade preempt would have pulled E/W out of 
their cold slam. For example, West could bid a "good" 4NT over 4S (or 
whatever is positive in his system) and East would surely have bid slam. 
This dependis on what exactly 2D promises ; if it's G/F, a constructive bid 
from West is automatic.
I'd expect E/W to come at 6D about 75% of the time ; allowing for 
pro-NOS-weighting as it's practised, and assuming N/S are indeed wild 
preemptors, I'd adjust to 60% of 6D= and 40% of 5D+1.

I'll ask my regular partner (a stark raving preemptor) whether he considers 4S.

Best regards

   Alain