rebid to
be pretty much anything, but that (in particular in K/S)
forces a rebid by responder and leaves the auction unclear.
(Playing Standard, who is responsible for starting the
search for a 4-4 major suit fit?)
-2
is a problem auction
for Standard bidders. To solve this, strong notrumpers
have often chosen to play 2 as game forcing. K/Sers
have different problems; 2 can sometimes be bid on
weaker hands than Standard bidders. Then if opener has an
unbalanced hand, disambiguating the responding hand's values
can be difficult.
The Standard approach is to allow the 2 rebid to
be pretty much anything, but that (in particular in K/S)
forces a rebid by responder and leaves the auction unclear.
(Playing Standard, who is responsible for starting the
search for a 4-4 major suit fit?)
A set of rebids, attributed to Eric Kokish, attempts to handle these problems. They were designed for use along with a weak NT, but work with any NT range. I'll assume 15-17 NTs and others can transpose from there.
1-2; ?
= 5+, forcing
= 4441 exactly
= good club raise
= bad club raise
= 16+, good 6-card diamond suit
, 3 = splinters in support of clubs
Responder's major suit rebid is normally a 4-card suit,
but can sometimes be just a stopper; opener is not expected
to go past 3NT. Opener's 2 and 3 deny a four-card
major, but 2 often contains one.