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NEGJUMP.CDA
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1995-08-26
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NEGATIVE DOUBLES OF JUMP OVERCALLS
If playing negative doubles, they apply in all situations, and:
New minor suit responses by an unpassed hand are forcing.
New major suit responses are invitational, not forcing.
This chapter assumes that four-card major suit openings are
permitted. "Five-card-majorites" will want to modify some of what
follows.
After a negative double, opener must be careful to make a forcing
bid if game is likely. A jump in a new major suit, when the suit
has been implied by the double, is not forcing:
South West North East
Pass 1C 2H Dbl - implying spades
Pass 3S - invitational
A jump in a new minor suit, or a major that has not been implied,
is always forcing.
A 2NT response is not forcing, 3NT shows 16-18 HCP:
South West North
1C 2D 2NT - 11-12 HCP
3NT - 16-18 HCP
With a 13-15 HCP notrump hand, North must make a negative double
and then bid 3NT.
When opener bids notrump opposite a negative double, a minor suit
rebid by responder is not encouraging:
South West North East
1C 2S Dbl Pass
2NT Pass 3D
North would raise notrump with a suitable hand, so the non-forcing
3D bid shows a dislike for notrump and no great strength: S-2
H-QJ32 D-AJ10432 C-J3. Opener needs a good diamond fit in order to
bid 3NT over 3D.
In all cases of negative doubles after a jump overcall, if there
is an unbid major responder could have a good major suit with a
game-going hand. He could not just bid the major, because a minimum
bid in a new major is not forcing. If there is an unbid minor, the
negative doubler could have a long strong holding in a minor with
too weak a hand to make a (forcing) response in the suit. Finally,
any negative double may be based on a notrump hand.
A cue bid response to a takeout double is forcing to a limit
situation, while a cue bid by the negative doubler is a "com-
petitive cue bid." See the introduction to the book "Cue Bidding"
for a full discussion of "limit situation" and chapter COMPETITIVE
CUE BIDS in the same book.
Let's take each possible jump overcall in turn:
South West North
1C 2D Dbl
This double implies support for both majors, but may have only one
major plus club support, or a notrump hand. This sequence is the
only one in which the doubler promises to bid again if opener bids
an implied major. If he has support, he will raise; if not, he will
bid. Either way, he won't pass. Accordingly, this double requires
10 points or more, and opener need not jump in a major to show a
good hand with 15-16 points. A jump would therefore be forcing and
would show a better hand.
Some typical hands for this double:
SQJ32 H-KJ53 D-87 C-K92 (with a king less, just pass)
SK863 H-K42 D-AJ7 C-974 (but 2NT might work out better, because you
will have to pass a 3C bid)
SQJ873 H-AKQ D-53 C-J76 - bid spades next, a forcing bid
SK964 H-94 D-983 C-AK52 - raise a spade bid, otherwise bid 3C
SQJ9 H-AK8 D-A52 C-9852 - bid 3D next (equivalent to 3NT)
South West North
1C 2H/2S Dbl
1D 2H Dbl
These doubles imply four or more cards in the unbid major. The
doubler must have enough points for safety if opener is minimum.
The strength required therefore depends somewhat on the degree of
fit with opener's suit. With a minimum hand, the doubler can pass
a jump in the implied major.
South West North
1D 2S Dbl
Since this double (as with 1D-1S-Dbl) does not imply hearts, the
doubler will not pass a 3H bid by opener. He will raise or bid
something else. Opener should therefore not jump to 4H without full
reversing values.
South West North
1D 3C Dbl
This double implies four or more spades, plus either hearts or
diamonds. The doubler will not pass a 3H bid, so opener does not
have to jump with S-A3 H-J1032 D-AK875 C-A7. A jump to 4H might
interfere with North's plan to bid 3NT if opener doesn't bid 3S.
The doubler may well pass a 3S bid, however, so opener should bid
4S holding the same hand with the majors reversed.
South West North
1H 2S Dbl
The doubler probably has both minors, but could have only a good
diamond suit (if South bids 3C, North can bid a non-forcing 3D
without increasing the bidding level). A minimum double should have
good tolerance for hearts. If opener jumps in a minor, that is
forcing.
South West North
1H/1S 3C/3D Dbl
North implies support for the unbid major. Opener is unlikely to
have spades when she opens 1H, so there is no reason to stretch for
this double when the opening was 1H and the doubler has just four
spades. The sequence of 1H-3C-Dbl or 1H-3D-Dbl therefore implies
a five card spade holding, or a very strong four.
North might have three card support for opener's major, if the hand
is unsuitable for a raise. With four card support, however, he must
raise, not double. South can rebid in the unbid major with a good
three card holding, if that seems best, because the doubler cannot
pass without four cards in that (implied) suit:
South West North East
1H 3C Dbl Pass
3S Pass Pass Pass
South has S-AJ7 H-Q10632 D-KQJ C-64, North S-KQ86 H-84 D-A10732
C-97.
South West North
1S 3H Dbl
1H 3D Dbl
Opener will usually have a strong hand if his suit is not five
cards or longer (else what was he going to bid after a two-level
response in West's suit?). These doubles therefore tend to deny
adequate trump support for opener's suit, and he should avoid
rebidding in that suit if it is a weak five-carder.
This chapter applies to natural overcalls that show only the suit
named. For defenses against conventional overcalls that show two
suits, see chapter DEFENSE AGAINST TWO-SUITED CONVENTIONS in the
book "Countermeasures."