[straube]

Kungsgeten, on 2016-May-10, 07:01, said:

I like the idea of the 1D-1S; 2C rebid, but in that style I guess you cannot open 5422 hands with 1D, unless the hand is specifically 4-2-5-2?

Yeah, that would be true. I wasn't exactly sure which hands you open 1D. I assumed 4D/5C opens 1D and most of the 5422s open a weak NT. Probably a wrong assumption.

I basically cobbled together what we're using for our nebulous diamond (I really like our structure over it) and replaced the 1N rebid with the strong/minimum diamond hands.

[nullve]

I assumed that the 1♦ opening was standard unbalanced, but made tacit use of a trick on minimum (say, rules of 19-24) hands with either (31)(54), (40)(54), (41)44 or (41)(53) shape that's not really available if the 1♣ opening is of Polish or Swedish type. Assuming T-Walsh and switched 1M responses to 1♦, so that

1♣-1♦ = 4+ H
1♣-1♥ = 4+ S
1♦-1♥ = 4+ S
1♦-1♠ = 4+ H,

the trick is to open 1♣ with a majority of black cards, 1♦ with a majority of red cards and let

1♣-1♦; 1♠ = 4+ S or 10-15, 31(54)
1♦-1♥; 1♠ = 4+ H or 10-15, 13(54).

This largely frees up the 2♣ rebid over 1♦-1M(=4+ OM), which can now quite comfortably be played as F1 and maybe primarily serve as a sort of OM raise. (This partly explains why I don't need gnasher's 1N gadget.)

A GCC legal version of the above is to to play

1♣-1♦ = 4+ S
1♣-1♥ = 4+ H
1♦-1♥ = 4+ H
1♦-1♠ = 4+ S,

open 1♣ with a majority of rounded cards, 1♦ with a majority of pointed cards and let

1♣-1♦; 1♠ = 4+ H or 10-15, 13(54)
1♦-1♥; 1♠ = 4+ S or 10-15, 31(54).

[perko90]

Adjustments will be needed depending on whether we're in a strong Club context or a Standard(ish)/Polish one. I'll assume the latter with "natural" meaning 1♦ = 4+ D's. Even in this context, I believe the 4 D's & 5 C's hands are best opened 1♦.

I like after 1♦-1M:
1♠ over 1♥ = natural, 4 S's
1NT = 11-15 HCP "natural", <3 in M (usually a stiff) and < 6 D's (the most usual distribution is (13)(54), but 1444 possible over 1♠ as is 22(54) with weak majors)
2♣ = D's, either a 6+ D suit or various strong hands w/ 5+ D's (reverse, 5/5 minors, BWDH (long D's and 3-card support) etc.)
1-under raise (2♦ over 1♥ or 2♥ over 1♠) = minimum 3-card raise
2♦ over 1♠ = 5+ D's & 4 H's
2M = 4 pc raise
3♣ = 5/5 minors, invite (like Precision) [if playing Strong Club, this could be the weak 5/5 and going thru 2C could show the invite version]

After the 1NT rebid:
2♣ = pass or correct (always to a 5-card minor, except 1444 over 1♠)
2♦ = similar to NMF, but opener can bid 2M w/ a 2-card tolerance
other bids natural, including:
3♦ = sign off