The meaning of a 4NT bid and the following bidding style depend entirely on the on CONTEXT of the 4NT bid.
1. Quantitative 4NT
A. A direct Jump to 4NT from a NT bid in any of the following balanced sequences (and no other):
(i) 1NT(opening) - 4NT
(ii) 2NT(Opening) - 4NT
(iii) 2-2X-2NT - 4NT
Note: Following a 2 & opening 4NT Quantitative never applies
Valid responses are:
PASS (not allowed for (iv) ) No interest in SLAM
Accepted - no
interest in a grand slam
ERKCB responses <= 5NT Showing interest in a SLAM and top honours
2. 2 Sequences
4NT following a 2 opening and any Positive response, is ALWAYS for Kings:
This bid should normally only be made by the 2
bidder. Occasionally if the NT bidder makes a control request, the
response to which would reach or pass 4NT then see this special case
given below: '4NT by responder'.
5: 0 Kings
5: 1 King
5: 2 Kings
5: 3 or 4 Kings
A positive response to 2C shows 1 or more controls (K=1;A=2)
With this response the 2 bidder therefore unravels the Number of Aces simultaneously.
Following this a 5NT request for other key honours, responses are:
6: No Queen of trumps
6: Queen of trumps
6: Queen of trumps with either the J of trumps or another useful queen
Responses should not bypass the agreed suit.
When the initial response to 2 is a negative (2 or 2NT which denies Kings or Aces);
4NT will ask for Queens with the three above responses given at the 5
When responder bids 4NT or passes it:
Then bidding 4NT shows 2 or 4 Kings. Presumably previous responses can unravel this.
Then passing above 4NT shows 1 or 3 Kings. Again, presumably previous responses can unravel this.
(in fact a modified TURBO)
2 bidder may continue with 5NT as above or proceed to the agreed suit.
3. Cue Bidding and TURBO 4NT
Turbo is automatic in these cases:
Bidding 4NT shows an EVEN number (2 or 4) of KeyCards(KC) while bypassing 4NT declares an ODD number of KC (1 or 3).
- Following cue-bidding TURBO always follows. (A splinter counts as a cue bid - but swiss bids do not.)
- However, it is automatically still TURBO if 4NT is not reached with a jump (excluding quantitative raises)
Key Cards are the 4 Aces and K of trumps as in RKCB.
When a major suit is agreed below 3NT and either player bids 3NT, without using trial bids), then
this shows an EVEN number of KC and a 4-level bid bypassing 3NT will show an ODD
number as above.
There is another aspect to TURBO for indicating the Queen of trumps:
Partner needs to be aware that in these sequences bidding game is only
a warning about the Queen of trumps and partner should NOT treat it as
a stop bid if a slam is in the offing.
- In the case of a Major agreement 4Ma is bid and not bypassed when
NOT holding the Queen of trumps. Bypassing 4MA implies holding
the Queen of trumps.
- Similarly wih a minor agreement, 5mi is not passed without holding the queen.
4. 4NT with a jump is ERKCB
(That is when it is not Quantitative or if 2C was the opening bid. Also not if cue-bidding followed agreement)
The trump suit is either already explicitly known otherwise
implicitly now defined as the suit bid just prior to the 4NT bid.
See ERKCB responses.
In some ERKCB sequences there may be 6 KEY cards (i.e. that
is additional key kings) Valid kings in known suits of the 4NT bidder.
Sequences for 6KC:
A) 1X - JY and subsequent trump support shown for either X or Y.
In this cases 4NT bidder must possess a minimum of 2KC
A rebid of 5NT following a 4NT EKCB shows all 5 Key cards are held and is a Grand Slam try..
If the existence of the agreed trump suit has not been located, then, the primary response to a 5NT bid is to seek the Queen.
Responder bids 6 of the agreed suit without the queen, and the suit of any hithertoo undeclared K.
If the queen is discovered, then, 5NT is seeking further
information. Again if nothing useful is around the idding closes
in 6 of the agreed suit, otherwise the responder bids location of the
feature e.g. A void, a useful side K not inferred in
5. Following special 3C/D 2-suited sequences
Responses show a conservative LTC where K are not counted unless
supported by the Ace, A King supported by a Queen may be counted,
however the Queen cannot be counted. Singletons without the Ace &
Voids are counted as 1 & 0 LTC counts in their suits.
5C: 8LTC; 5D: 7LTC; 5H:6LTC; 5S:5LTC;5N: 4LTC This
may occur if preference is not given to opening 2C (Typically opening
2C is valid if one suit has a lower LTC than the other. Stronger
2-suited sequences are not able to indicate which suit is superior.