[blml] A lawbook wish: Clarify "convention"

[Jerry Fusselman]

The correct ruling often depends on whether or not a certain call is a
convention.  I hope the new lawbook clarifies the definition of
convention.  Currently, it is, "A call that, by partnership agreement,
conveys a meaning other than willingness to play in the denomination
named (or in the last denomination named), or high-card strength or
length (three cards or more) there. However, an agreement as to
overall strength does not make a call a convention."

The last sentence seems oddly specific, but my main problem with this
definition is the phrase "other than," which different things to
different readers.  Consider the sequence 1S - 2NT - 4S without
competition, where 2NT is a Jacoby game-forcing raise, and 4S shows a
weak hand and no singletons or voids.  Some say it is not conventional
because he does indeed want to play in spades.  Some years ago, this
was appeared to be the majority opinion on BLML.  Indeed, such people
would also say that later, 5S in response to Blackwood would not be
conventional either, because he still wants to play in spades.

Others disagree with this position, saying that the information
content is what matters, and since 4S denies singletons and voids, 4S
has a meaning in addition to a willingness to play in spades---and is
therefore a convention.  My guess is that this is correct, but
sometimes directors rule differently---probably due to the vagueness
of "other than" in the definition.

Is "in addition to" a special case of "other than" or not?  I.e., does
the meaning of a call have to be 100% other than to qualify as "other
than?"  I think that the definition of convention could be worded
clearer to achieve more uniform understanding.

Secondarily, can SO's add other categories of conventional?  I am
thinking here of the ACBL's definition in their GCC (General
Convention Chart):  "An opening suit bid or response is considered
natural if in a minor it shows three or more cards in that suit and in
a major it shows four or more cards in that suit."

So the auction 1C - P - 1S would be ACBL-artificial if 1S shows
three-plus spades.  If there is nothing else unusual about the meaning
of 1S, then it would seem to be simultaneously artificial and not
conventional.  Wow!  Or maybe it is conventional in ACBL land, despite
the definition in the law book.  Does anyone know or have a guess?

Jerry Fusselman