4.1
If
the opponents DOUBLE, all conventional responses are "on". For example:
1NT -- (double) -- 2C = Stayman
-- 2D = (transfer to hearts)
If
the opponents BID over your 1NT opener, Stayman and transfers are "off".
Bids
are natural except for a cue bid, which can be used with game force strength as a
substitute for Stayman.
If
the opponents intervene over a conventional response, bids carry the same meaning as if
there were no intervention. A bid says,
"I'm bidding voluntarily, so I have a real fit for you."
1NT -- (Pass) --2D -- (Double)
2H
= Real fit for hearts (pass with only
two hearts)
4.2
Stayman
and Jacoby transfers for the majors are used.
2NT -- 3C = Stayman
-- 3D, 3H = Jacoby transfers to hearts and spades respectively.
-- 4C Gerber
-- 4NT = inviting a slam in notrump.
3NT -- 4C = Stayman
-- 4D, 4H = Jacoby transfers to hearts and spades respectively.
4.3
1H
and 1S openings show a five-card or longer suit. Responses:
1H -- 1S = at least four spades, 6 or
more points. Tends to deny a heart fit.
--
1NT = 6 -10 points, denies four spades or 3
hearts. NOT forcing.
--
2C, 2D = 11 points or more, promises at least four of the suit.
--
2H = three-card or longer heart support, 6-10
dummy points.
--
2NT = Game-forcing raise ("Jacoby 2NT"), 13+ dummy points.
Asks opener to show a short suit to help responder evaluate
slam prospects.
--
2S, 3C, 3D = strong jump shifts, Invite to a slam
--3H
= limit raise (10-12 dummy points with three or more hearts).
--3NT
= 15-17 HCP, balanced hand with two-card support for partner.
--4H
= usually 5+ hearts, a singleton or void, and
fewer than 10 HCP.