[Kungsgeten]

Once again I've been thinking about relays over our 2C opening and I'll be happy to hear comments. We usually don't open 2C light, so the range is about 12-15 hcp. It includes the following shapes:

a) 6+ clubs, but usually not 6-5.
b) (14)35, so 4-1 in the majors, three diamonds and five clubs.
c) 4-4-0-5

If having 5422 or 5431 with short diamonds we don't open 2C.

A 2D response is used as a relay. The relay isn't game forcing; it could be invitational (somewhat balanced or clubs support). If invitational then will not have a 5+ major.

2C-2D;
2H = A four card major (but see 3C).
...2S = Relay or 4+S.
...2NT = F1 with 4+H.
...3C = INV.
...3D = Asking strength and club suit quality.
...3H = INV with both majors.
2S = 6+ clubs single-suited, or minimum 6+C and 4D. 2NT is GF relay.
2NT = "Natural". 6322 with extras and suitable for NT.
3C = Minimum with 5+C, 4H, short spades. 3D is GF relay.
3D = Max with 6+C and 4D. 3H asks shortness.
3M = Undefined (we currently play it as 6-4 max).
3NT = Undefined

2C-2D; 2H-2S;
2NT = Short diamonds, so at least 6-4. 3C is NF with 4S, while 3D asks major.
3C = 5+C, 4S and short hearts. 3S is now invitational, while 3D relays.
3D = 4-4-0-5. 3S is now invitational.
3H+ = Zoom into max hand with 5+C, 4H and short spades.

I don't believe shape is fully resolved when opener has 6C and 4D (especially not when minimum, where the diamond suit probably will be lost). It can also be hard when opener has 6+C, 4M and short diamonds (hard to distinguish singleton from void).

[straube]

Would it help if you restricted 2D to be any GF OR GI with a 4-cd major?

2C-3D=GI 6D
2C-2N=GI 3C or 3352
2C-3C=raise

Then your 4405 can bypass 3C immediately.

Perhaps 2C-2D,
.....2H-various minimums
..........2S-GF asking
..........2N-4S, inv
..........3C-4S, inv
.....2S-minimum with 4H
..........2N-4S, inv
..........3C-4S, inv
..........3D-asks short
.....other-maximums

[TylerE]

Maybe you have your reasons, but I find any such 2♣ sub-system infinitely more playable when it promises 6.

[Kungsgeten]

TylerE: We play a natural 1D opening, that's the reason. I agree that having 2C promise 6 (or having it deny a 4+ major) would make it easier.

straube: I don't know how much it would improve, but its an idea. You got me thinking about moving some stuff, which might make it possible to resolve 6-4 hands with short diamonds.

Same structure as original post, but:

2C-2D; 2H-2S;
2NT = 5+C, 4 hearts and short diamonds. May have 4-4-0-5 but not 5431.
...3C = Non-forcing with 4S. Opener corrects with 4-4-0-5.
...3D = GF relay.
......3H = 4-4-0-5.
......3S+ = 6+C, 4 hearts, short diamonds.
3C = 5+C, 4 spades and short hearts.
3D = 6+C, 4 spades and short diamonds.
3H+ = 5+C, 4 hearts and short spades (max).

This would mean that the clubs + major two-suiters resolve at:

3H = 5431
3S = 6421
3NT = 6430
4C = 7420
4D = 7411
4H = 7510

[PrecisionL]

I play a relay in one Partnership, but the 2♣ opening can have a 4-cd major. Too much memory work.
2♣ - 2♦ (Asking):

2♥ = Unknown 4-cd Major
2♠ = Unbalanced Maximum
2NT = Balanced Maximum
3♣ = Unbalanced Minimum

[Edited 1/25/2020 0855 hrs]

I play conditional transfers in another partnership (2♣ promises 6-cds and no 4M). This works well with invitational or better hands, and weaker hands that also have a fit for ♣s.
2♣ - 2♦ (Conditional Transfer with 5+♥)

2♥ = 2+♥ and Minimum
2♠ = 0-1♥ and Stopper, min.
2NT = 0-1♥ and maximum with [spade stop]

3♣ = 0-1♥ and minimum

3♥ = 3+♥ and maximum

[straube]

My concern was to avoid playing 3C in a misfit. For example, inv 4261 opposite x4x5. I suppose 4351 could play a 4-3 heart fit. Actually, you wouldn't know if you were leaving a 5-1 or a 6-1 club "fit".

Anyway, such would be rare and your structure has comfortable pattern resolution at only +1. We also group 7510 with short-legged

What's your 2D opening? If 3-suited short diamond, can't you place 4405 there?

[Kungsgeten]

Our 2D opening is natural and weak at the moment. We place (43)15 and 4414 into our 1C opening and basically treats them like balanced. It has worked OK so far, but isn't optimal. However I think its the better choice compared to devoting the 2D opening to these patterns, since we'd still have to open 2C on a five card suit even with that 2D opening. We don't put 4-4-0-5 into 1C since responder will treat opener's hand as balanced (or strong) in competition.

[Zelandakh]

How are you using your 2NT response here Kungsgeten? It seems to me that you can solve most of the issues by using 2NT as a GF relay and moving whatever hand you have there down to 2♦. Now the 2♦ response becomes any invite without a 5 card major plus any GF hands that were in the original 2NT response, which should not be too difficult to handle. In fact, the relays can almost be turned into natural bidding:-

2♦ = INV relay
... - 2M = 4M
... - 2N = no 4M, min
... - others = no 4M, max
2M = 5+M, constructive
2N = GF relay
... - 3♣ = 6+♣, <4♦
... - ... - 3♦ = relay
... - ... - ... - 3M = 4M, 6+♣
... - ... - ... - 3N = no 4M, 6+♣
... - 3♦ = 6+♣, 4♦
... - 3M = 4M, 5♣
... - 3N = 4405
3m = nat, weak
3M = nat, GF
3N = nat
--

This seems to be the easiest way of achieving the design goals within a structure that is logical and easy to remember.

[straube]

I think one of his design goals is full shape resolution.

[nullve]

 Kungsgeten, on 2020-January-22, 08:44, said:

Once again I've been thinking about relays over our 2C opening and I'll be happy to hear comments. We usually don't open 2C light, so the range is about 12-15 hcp. It includes the following shapes:

a) 6+ clubs, but usually not 6-5.
b) (14)35, so 4-1 in the majors, three diamonds and five clubs.
c) 4-4-0-5

If having 5422 or 5431 with short diamonds we don't open 2C.

I guess Swedish system regulations are the main reason you open 2♣ instead of 1♦ with (41)35. (1♦ = "4+ D" gets 0 dots, whereas 1♦ = "4+ D or (41)35" gets 2 dots.)

Your "12-15" range sounds rule of 21-ish to me, so I assume you already pass hands with 10-11 hcp and either (41)35 or 4405 shape. Since most of these are opened by virtually all tournament players these days, your system appears to have a hint of Silent Club to it, by comparison.

But if you don't mind taking your system a tiny step further in the direction of Silent Club, how about

P = "normal" OR 10-12 hcp and either (41)35 or 4405
2♣ = "(10?)12-15, 6+ C" OR 13-15, (41)35 or 4405

? Here the 2♣ opening promises either 6+ C or MAX, so every sequence that currently ought to be F2N only, like the sequence 2♣-2♦; 2♠-2N(NF) in classic Precision, can now quite comfortably be played as F3♣.

[straube]

I don't like passing 12 pt hands, but nullve's idea solves a lot of problems. You can invite wit 2 clubs, you don't need to worry about an underpowered misfit situation, and you get your relays.

[Kungsgeten]

Nullve: We could include (41)35 in our 1D and still have the same system classification. We use 1D-1NT as a relay, and the 2D raise is frequently made on three cards. If 1D could be a three card suit the raise structure would need to change, probably we'd need to respond with a 3 card heart suit sometimes. Also the relays would be cramped (but they would work if the 2D opening was changed into constructive).

We thought about silent club for a while, but thought it seemed too esoteric and random. If going that way I think it makes more sense to pass with the full up to 15 range. Then 2C could either promise a 6+ suit, or those hands could be passed too and 2C could be some kind of preempt.