From: martel@spider.cs.ucdavis.edu (Chip Martel)
Newsgroups: rec.games.bridge
Subject: Restricting Conventions
Date: 29 Sep 92 22:51:46 GMT
Reply-To: martel@spider.cs.ucdavis.edu (Chip Martel)


This post is a followup to several articles which have discussed
(usually by criticizing) various restrictions on allowed conventions.
As someone who has been very much involved in this both as a player
on the world level, and as a member of the World Bridge Federation
Systems committee I would like give my views on this.

First of all, the laws allow restrictions on conventions and very weak
natural bids so it Legal to have some restrictions. As to whether this
is wise, I suggest the following principle: it is wrong for a pair to
gain a substantial advantage by playing a convention due to its SURPRISE EFFECT.
  The surprise effect is the gain which comes purely because the opponents
have not had a reasonable chance to prepare to play against the convention.

Note that the surprise effect is most serious when a bid is weak. An 
extreme example of this occured in 1982 when a Dutch pair Mass-Rabatu played
a system in the world pairs where an opening pass showed a normal 1S opening
and a 1S opeing showed a normal pass. The opponents had no advance notice of
this, and since only three boards per round were played, there was no
realistic time to prepare much of a defense (also at this time, such a system
was much rarer, so there was much less known about how to defend against
this). I doubt they thought their system had any theoretical merit, but the
surprise factor gave them a big edge.

In order to prevent the surprise effect it is quite reasonable
to take several things into account: the more boards being played, the more
time opponents will have to prepare; the more sophisticated the opponents,
the more likely they can prepare a defense; the more common a convention is
the more likely it is that the opponents will be prepared.

Based on these factors the  ACBL has made some good decisions as well as 
some poor ones:
 starting with the second round of the bidding, you can play
anything you want. This is quite reasonable since this will almost always
be a constructive auction where the surprise effect will be small.
  On the first round of bidding, only approved conventions can be played
in most events (with the approved list more stringent in limited events).
This is quite appropriate as a general concept: you avoid the surprise effect
by knowing you must prepare for a limited set of early round conventions.
However, I will admit that the decision of what should be on this list is
at times questionable. Many of the decisions seem quite arbitrary, and are
not consistent with the notion that a convention should only be kept off the
list if it is rarely used and hard to defend against.
  In National events almost anything goes. This in my opinion goes too far.
In a national pair event, there is not enough time to prepare if your 
opponents are doing something very odd. In the team events written descriptions
of unusual methods should be available in advance.

Notice that it is not simply that the ACBL is too restrictive, but it is more
that they have not always made the right distinctions about what should and
should not be allowed.

Finally, let me make a pitch for restricting conventions which have too high
a surprise effect. If you allow all conventions without advance disclosure
(or in pair events where you may be overwhelmed by too many odd conventions),
then you create a setting where there is a competition to find methods with
the greatest surprise effect, often without any real bridge merit. In 
particular, it encourages pairs to play one method until it becomes a bit
familiar, and then move onto something differnet. A few may find this a
good game, but the vast majority do not. It also is likely to create a
climate for poor ethics. Somehow most pairs playing very odd
systems are not very forthcoming in their system descriptions.

In the 1990 World Pair Olympiad no conventional openings which could be 
weak and did not promise length in a known suit were allowed (except
multi which no longer has any surprise effect). This was greatly
appreciated by almost all the contestents from all over the world
(even many who sometimes play odd systems commented on how nice it
was not to have to deal with some completely unexpected conventions).

Chip Martel