(context: RHO opens strong and artificial 2C at IMPs when you have
void/K86/Q7653/AT832, vulnerable vs. not vulnerable)
Post by KWSchneiderIf the final contract is 4S, any entry to dummy will allow successful
finesse(s). More importantly, the 2N overcall (converted to 3m), will
prevent responder from bidding 2D (not a big deal), but more
importantly, prevent opener from bidding 2N.
Not really; it's highly common for X by opener to show the big balanced
hand (after responder passes, typically showing a game force). Suppose
there are 23 points balanced on your right (which is about the weakest
hand that would bid 2N). Now the responder will have a choice of a
penalty pass (if they make it, it's probably correct, and the
vulnerability gives a good chance it's correct), or finding game in
whatever major they happen to have (knowing that opener will have at
least 2-card support, probably more). The opponents will almost
certainly reach the right spot, as 3 of a minor doesn't pre-empt any
of responder's likely responses except possibly Stayman.
I'm generally in favour of interfering over 2C, but when you're doing
so, you're hoping that opener does /not/ have a balanced hand. Many
pairs don't have sophisticated agreements in that spot, so opener is
stuck trying to describe which major they have, and how long it is, and
how strong it is, using only 3 of a major and 4 of a major as possible
bids (it would be logical to define 4 of a minor here as something
artificial, but few systems do that). The hope you have here is that the
opposing partnership will end up in game when they should be in slam, or
vice versa, due to being unable to communicate much information about
how good the fit is in the trump suit. (The overcall can also typically
gain by allowing partner to judge a sacrifice accurately, although at
this vulnerability it's very unlikely that a sacrifice will help.)
Meanwhile, there's very little chance of ending up being stuck having to
declare unless opener's hand is balanced, as they typically have to bid
something to show their suit when they have an unbalanced hand. So the
only risks are that opener is balanced (probably not all that risky when
you have a 0355!), or that the information about your distribution helps
opener make a slam that would otherwise fail (with an outside chance
of responder being very weak, and the information helping opener make a
/game/ that would otherwise fail, but the odds of this are miniscule).
--
ais523