[BLML] The Monty Hall trap

Jerry Fusselman jfusselman at gmail.com
Fri Dec 17 03:44:59 CET 2010

On Tue, Dec 14, 2010 at 8:47 AM, Eric Landau <ehaa at starpower.net> wrote:
> On Dec 14, 2010, at 12:44 AM, Jerry Fusselman wrote:
>> On Mon, Dec 13, 2010 at 11:23 AM, Eric Landau <ehaa at starpower.net>
>> wrote:
>>> On Dec 13, 2010, at 11:22 AM, Thomas Dehn wrote:
>>>> Of course if you are aware of your partner's tendencies
>>>> to psyche in certain auctions, or you run into a bidding
>>>> sequence where your system makes a psyche low risk,
>>>> that has to be disclosed to opponents.
>>>> But that does not make the psyches illegal. And they exist
>>>> in natural systems, too. Say,
>>>> 1H X 1S
>>>> Here, responder's 1S quite frequently is a psyche.
>>> That's not, however, the way things work in the ACBL, where even this
>>> common and well-known "baby psych", once perpetrated within a
>>> partnership, immediately morphs into an illegal implicit agreement,
>>> which, as such, may not be repeated.
>> Why do you say illegal?  It could be described as a conventional
>> defense to a conventional call, perfectly legal under even the GCC.
> Because it also could be -- and has been -- described as an "agreement
> [] whose primary purpose is to destroy the
> opponents’ methods", illegal under even the Superchart.  This
> provision has been used primarily to ban any method with even a vague
> hint of "psych" to it.

I see what you mean.

I would have agreed with you, Eric, had you written, "immediately
morphs into a might-be-deemed-illegal implicit agreement."  I suppose
that almost any unusual agreement can be ruled illegal by almost any
ACBL director at any time if he decides it might "destroy the
opponents' methods"---whatever that means.

How about the agreement that 3S in 1S-X-3S is preemptive?  If 3S is
not designed to destroy the opponents' methods, I don't know what is.

My hypothesis is that the only reason that that 3S it is allowed in
the ACBL by all directors is because it is so widely employed.

Eric, your original statement was that this possibility of 1S in
1H-X-1S was an "implicit illegal agreement" not that it "might be
deemed an illegal implicit agreement."  There is a world of difference
between "might be deemed illegal" and "is illegal."

I would guess that most directors would allow 1S after 1H-X- to
possibly not show spades, if that was disclosed with adequate
precision.  Do you think I am wrong?

Jerry Fusselman

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