With my regular partner we started to play 2♦ = 5-10 hcp and 5-4 (at least) in majors. In that spirit, I thought whether it's worth to use 1NT as a weak hand with 5-4 in minors. Specifically, responses could be something like
(a) 2♣/♦ = to play
(b) 2♥/♠ = 12-16 hcp with 5+ cards, non-forcing
© 2NT = 17+ unspecified
(d) 3♣/♦ = preemtive
(e) 3NT = to play
(h) 3♥/♠ = solid 7 cards
The immediate problem is that you may miss a 5-3 fit in majors. For instance, opener may has the following distribution: 0454 or 1345 or 0355. I try to solve this problem with (b).
Another problem is that we may miss a game in majors. I try to solve it with ©. Specifically, opener rebids:
i) 3♣/♦ with a minimum hand, denying 3 cards in majors
ii) 3♥/♠ = (7)8-10 hcp and 3-4 cards in that major
iii) 3NT = 8-10 hcp with exactly 2254 distribution
The most serious problem, though, is that you loose the 'natural' 1NT opening. There is a huge discussion on the benefit of 1NT, either as strong or as a weak opening bid. By employing the aforementioned approach, I borrow (with some mods) from the TOP3 system the 1♦ = 14-16 hcp and balanced.
Here are some thoughs for the responses after the 1♦ opening bid:
a) 1♥ = 8+hcp, with no major
b) 1♠ = 0-7 hcp
c) 1NT = 0-7 hcp with 54 in minors or 6+ cards in a single minor
d) 2♣ = stayman
e) 2♦/♥ = transfer
However, the problem with that is that you can be easily overcalled. In such a case, some thoughts are:
a) over 1♥/♠ overcall, responder passes with a weak hand, doubles with 8+hcp and the rest is the same
b) over 1NT overcall, responder passes = transfer for double, double = transfer for clubs, clubs = transfer for diamond, etc.
c) at the 2-level overcall you can use Lebenshol or any other convention
Note, that under such an approach I use 1♣ = 11+ with any hand.
Any thoughts are more than welcome
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