User:Brian/Bridge/Quantitative notrump raises
When partner has opened 1NT, 2NT, or 3NT, or has opened 2♣ and rebid 2NT or 3NT following a 2♦ relay, a notrump response is often quantitative, i.e., it is natural and shows a specific amount of strength.
Meanings of quantitative raises and responses
- A quantitative raise to 2NT is an invitation to 3NT.
- A quantitative raise to 3NT is to play.
- A quantitative raise to 4NT is an invitation to 6NT.
- A quantitative raise to 5NT is an invitation to 7NT. This bid is forcing; to decline the invitation, sign off in 6NT.
- A quantitative raise to 6NT or 7NT is to play.
For example, if a player opened 1NT, showing a balanced hand with 15 to 17 HCP, then:
- A 2NT response shows 9 HCP.
- A 3NT response shows 10–16 HCP.
- A 4NT response shows 17 HCP.
- A 5NT response shows 21 HCP.
- A 6NT response shows 18–20 HCP.
- A 7NT response shows 22+ HCP.
In all cases, if RHO has bid a suit, making a quantitative raise shows a stopper in their suit. (Without a stopper, you would not want your side to play in notrump.)
With support for partner's major
If partner has already shown a 5-card major using a Jacoby transfer, then in addition to signing off in notrump, if opener has 3-card support for responder's 5-card major, then signing off in that suit at the appropriate level is also an option. For example, after 1NT - 2D - 2H - 4NT, with 3+ hearts, opener can sign off in 5♥ or 6♥ in addition to passing or signing off in 6NT.
If partner has employed Stayman, you bid a 4-card major, then partner raised to notrump at the 3 level or higher, ignoring your major, it means they have the other major. With 4-card support for partner's major, you can sign off in that suit. For example, after 1NT - 2C - 2H - 4NT, opener can sign off in 5♠ or 6♠ in addition to passing or signing off in 6NT.
The sequence 1NT - 2C - 2S - 2NT shows 4 hearts by responder, so likewise the 3♥ and 4♥ sign-offs are available with 4-card support for hearts. However, the sequence 1NT - 2C - 2H - 2NT denies 4 spades (partner would have bid 2♠ if they had spades) so the only responses are Pass or 3NT.
When is a notrump response a quantitative raise?
It is important to be able to tell when a notrump response is a quantitative raise. This is particularly an issue in the case of 4NT, because when it is not quantitative, it is Blackwood, which is forcing.
In general, a notrump response not quantitative when suit agreement has been reached; instead 4NT is Blackwood and 5NT is Grand Slam Force. For example:
- A notrump raise following normal acceptance of a Jacoby transfer is quantitative since accepting the transfer does not communicate suit agreement (opener might have only two of the suit).
- A notrump raise following superacceptance of a Jacoby transfer is not quantitative since the superacceptance shows suit agreement.
- A notrump raise following a Texas transfer is not quantitative since an 8-card suit fit has been found.
- A notrump raise following a 2♥ or 2♠ response to Stayman is quantitative since suit agreement has not been shown (partner might not have the 4-card major you bid).
If partner has responded 2NT to your 1NT opening after interference by RHO, then it is not a quantitative raise; it is Lebensohl.
Quantitative raises after natural notrump overcalls
Quantitative raises can be employed in response to natural notrump overcalls by partner as well. In such cases, you don't need to have a stopper in opponent's suit, since partner has already shown it by overcalling. For example, in (1H) 1NT (P) 2NT, overcaller has shown 15-18 HCP balanced with a stop in hearts, and advancer has shown invitational strength (8 to 9 HCP). (Of course, the 4NT and higher responses are not likely in this situation since your side doesn't have enough HCP... unless opponents lied.)
You must only do this when you know that the overcall is natural rather than unusual notrump.