Post by dfmWhat should opener's cue bid mean after responder makes a negative
double? For example, should 1C (1S) Dbl (Pass) 2S be a game force, a
one round force, or something else?
I've been looking up some documented systems (e.g. Modern Acol, SAYC)
but they tend not to define this specific bid. (SAYC defines a cuebid of
LHO's suit as a generic game force, but 2S here is RHO's suit.)
One thing I worked on a while back was an Acol derivative which defined
every possible bid. That means that this bid was defined too; it would
show something like 18+ HCP without making a firm commitment to the
suit, but would not be game forcing if it became apparent that there
was a misfit. (Presumably the doubler would follow up by making a bid
to indicate the shape of their hand, or go right to 3NT if that seemed
appropriate.) I don't think this is necessarily the best use of the
bid, but the whole point of the system was to use consistent rules to
define everything and thus be easy to teach/remember, rather than
necessarily to make the best possible use of every bid.
I think almost all common systems would by default use the bid as
showing a strong hand, with the main question being as to just how
strong. If I made this double in an undiscussed auction and saw 2S as
the response, I'd try to reply naturally, and trust my partner to know
how strong their own bid was.
Post by dfmAnd after that cue bid, what should responder's 2NT mean? A minimum
with a stopper, or if 2S was GF, should 2NT be unlimited, or perhaps a
split range?
"Minimum with a stopper" is the interpretation I'd assume unless
something else was agreed; this is consistent with the normal bidding
pattern after inherently forcing bids.
Post by dfmI'm interested in what you think is best, as well as what you think is
standard. Assume standardish 2/1 framework if it matters.
I've mentioned what I think is standard above. However, I think the
/best/ use (if a little nonstandard) is along the lines of "I want to
bid notrumps but only have half a stop in the opponent's suit", because
it seems like a fairly common hand type in this situation and there
aren't many other ways to show it. This doesn't necessarily imply a
game force, so I'd use 2NT for minimum with the other half of the stop,
3NT for above minimum with the other half of the stop, and suit bids to
show a lack of even half a stop. (In the case where the opener has no
stop at all in the opponent's suit, it's quite likely that the
responder will naturally bid NT at some point if that's a viable
contract, as they'll have to have the stop entirely in their own hand.)
--
ais523