[Kungsgeten]

I've made a draft of a response structure over a 2C opening, which I think might work. This is intended when the opening shows 5+C (either 6+C or 5C and 4M). I know many prefer that 2C promises a 6+ suit, or denies a major, but that's not possible in all system designs.

Much inspiration comes from Zelandakh's transfer structure over 2C, but I've made some changes. The most major one being that responder is able to relay opener's shape (though there is some trouble with single-suiters). Feel free to suggest changes One thing I've done is that we can not stop in 2NT after starting with 2D or 2H, which is different from Zelandakh. I have the same limitations in the current response structure I play over 2C though.

2C---
2D = "Hearts or relay". a) 4--5 hearts, INV+ (not both majors). b) Weak with 6+H. c) GF relay.
2H = "Transfer to spades". a) 4--5 spades, INV+ (could be 4-4 majors). b) Weak with 6+S.
2S = Range ask. INV hand, balanced / clubs / single-suited.
2NT = Puppet to 3C. To play 3m, or SI in a minor.
3C = INV with 5H and 4S. NF.
3D = GF with 6+H.
3H = GF with 6+S.
3S = ?
3NT = To play.

Let's start with the 2D "hearts or relay" response.

2C--2D;
2H = 0--3H. If having 3H, then minimum.
...2S = Relay. => 2NT single-suited (3C asks shortness), 3C+ 5+C and 4S.
...2NT = INV with 5H.
...3C = INV with 4H.
...3D = 5+D GF (could be canapé).
...3H = COG with 5H.
2S = 4H, but not 4-4-0-5. => 2NT relays, 3C invite, 3H sign-off.
2NT = a) Max with 3H. b) 4-4-0-5.
...3C = Relay. => 3D 6+C and shortness, 3H 4-3-5-1, 3S 4-4-5-0, 3NT 2-3-2-6.
...3D = Not sure of game if opener has 4-4-0-5.
...3H = To play.
3C = 6+C and 4D, short hearts. (we can't invite over this). => 3D NF, 3H to play, 3S relay, 4m optional RKC.
3D = 0-3-4-6. (we can't invite)
3H = 1-2-4-6 or 0-2-4-7. (we can't invite)


So there is some problems when opener have 6C and 4C, since we're pretty high. The range for our 2C opening is about 12--15, but with 6-4 shape I guess it could be lower too. Also the single-suited hands with clubs relays pretty high. I think its okay if opener has 6C, but with 7+C it is awkward.


2C--2H ("transfer to spades");
2S = 0--2S.
...2NT = a) INV with both majors (5S-4H, 4-4, 5-5). b) SI with 5S.
......3C = Min with 6+C. => 3H 5-5 majors INV.
......3D = Max with 6+C. => 3H 5-5 majors INV.
......3H = Min with 4H.
......3S = Max with 4H.
...3C = INV.
...3D = 5+D GF (could be canapé).
...3H = 5-5, GF.
...3S = COG with 5S.
2NT = a) Max with 3S. b) 4H and 3S.
...3C = INV with 4S, not 4H.
...3D = 5S, INV or SI. => 3S minimum, others NAT max.
...3H = 4-4 majors INV.
...3S = To play.
3C = Min with 6+C and 3S.
3D = Max with 4S.
3S = Min with 4S.


2C--2S (range ask);
2NT = Min.
...Pass = Bal INV.
...3C = To play.
...3new = INV single-suited.
...3NT = To play.
3C = Max (as above).


2C--2NT (puppet to 3C); 3C---
Pass = Weak raise.
3D = To play.
3H = SI with 6+D.
...3S = Fit, but no accept.
...3NT = No fit.
...4C = No fit, but very good clubs.
...4D = Fit and accept.
...4HS = Shortness and fit.
...4NT = RKC for diamonds.
3S = SI with 3+C. => 3NT NF, 4C accept, 4new shortness, 4NT RKC.
3NT = Mild SI with 3C. NF.


2C--3red (GF transfer with 6+ major);
3M = Singelton or void major.
3NT = Non-serious, 2+ support.
4C = Very good club suit.
4M = 2 card support, minimum.
Others = Cue, serious (3S over a transfer to 3H could be non-serious).

[straube]

Does Zelandakh open 2C with 5C/4M?

If you don’t promise 6C it might be better to use a more traditional ask. You need to be able to stop in 2N when invitational misfiring. For example 2C-2D, 2N as 5 hearts seems wrong. After hearts don’t fit, you need to be able to show or deny a club fit.

Similarly, 2C-3C as 4S/5H invitational will occasionally place you in a 3-level misfit. Personally I like 2C-3C as a bump because it puts more pressure on the next hand ( than does 2N and drop).

Curious as to how many hand patterns you have to relay compared to us. You have to handle lots of patterns with only 5 clubs (although not 4D/5C I think).

Skeptical about relays being right here. You know Adam doesn’t use relays for his 2D open.

What do others think about use of relays here?

[Kungsgeten]

straube, on 2019-August-14, 18:39, said:

Does Zelandakh open 2C with 5C/4M?

Yes, if I remember correctly he plays 1D as wide-ranging (could be wrong here) natural unbalanced, and thus 2C needs to handle 5C and 4M (since he also plays five card majors).

straube, on 2019-August-14, 18:39, said:

If you don’t promise 6C it might be better to use a more traditional ask. You need to be able to stop in 2N when invitational misfiring. For example 2C-2D, 2N as 5 hearts seems wrong. After hearts don’t fit, you need to be able to show or deny a club fit.

Similarly, 2C-3C as 4S/5H invitational will occasionally place you in a 3-level misfit. Personally I like 2C-3C as a bump because it puts more pressure on the next hand ( than does 2N and drop).

At the moment we play 2C-2D as asking, and then opener rebids 2H when holding a four card major, 2S is 6+ clubs and shortness somewhere, 2NT/3C is "balanced single-suiter" max/min, and 3new is 6-4 max. We can't stop in 2NT here. We now play 2C-2M as constructive non-forcing (usually invitational) and usually with a five card suit.

I agree that the "Flannery invitational" hand is a bit awkward. Zelandakh uses 2C-2NT to show 5S and 4H invitational, so now you can stop in 2NT I guess. I've seen many partnerships use the rule "don't play 2NT opener has a six+ suit" though, and if opener doesn't have a major fit in this sequence he will have 6+ clubs.

Actually I'd also like to use 2C-3C as natural, if possible. We don't do that at the moment though (now we use it as a transfer to diamonds), so we don't lose anything compared to our current structure. I think it would be nice to use 3C as a mixed raise or similar (preemptive still going through 2NT).

straube, on 2019-August-14, 18:39, said:

Curious as to how many hand patterns you have to relay compared to us. You have to handle lots of patterns with only 5 clubs (although not 4D/5C I think).

Skeptical about relays being right here. You know Adam doesn’t use relays for his 2D open.

What do others think about use of relays here?

Well, if we're talking about a normal 2C opening of this kind, then the hand patterns included are:

- Short-legged two-suiters with 5+C and 4M.
- 4-4-0-5 pattern.
- 6+C and 4D pattern (maybe also 7+C and 5D, but not very common).
- Single-suiters with 6+C.

Something that I haven't considered in the version I've posted here though, is that we have the option to open 1C when holding a (43)15 pattern, and (42)25 could be treated as balanced. If were to say that 2C denies these hand patterns, then instead of "short-legged two-suiters with 5+C and 4M" it would just be (41)35 instead.

[straube]

Kungsgeten, on 2019-August-15, 05:01, said:

Something that I haven't considered in the version I've posted here though, is that we have the option to open 1C when holding a (43)15 pattern, and (42)25 could be treated as balanced. If were to say that 2C denies these hand patterns, then instead of "short-legged two-suiters with 5+C and 4M" it would just be (41)35 instead.

I've said before but open (41)35 1D and require 6C for 2C

[Kungsgeten]

Kungsgeten, on 2019-August-15, 05:01, said:

Something that I haven't considered in the version I've posted here though, is that we have the option to open 1C when holding a (43)15 pattern, and (42)25 could be treated as balanced. If were to say that 2C denies these hand patterns, then instead of "short-legged two-suiters with 5+C and 4M" it would just be (41)35 instead.

So if we exclude (43)15 and (42)25 the structure over 2C-2D seems to work better:

2C--2D;
2H = 0--2 hearts.
...2S = Relay.
...2NT = INV both majors (now 2C-3C can be used as some kind of raise).
...3C = INV.
2S = 3 hearts and 6+ clubs.
...2NT = Relay.
...3C = INV with 4H (we could miss a 4-4 spade fit here if opener is min with 3-4-0-6).
...3D = INV with 5H.
...3H = NF with 6H.
2NT = 4 hearts (not 4-4-0-5).
...3C = Relay.
...3D = INV with hearts.
...3H = NF with 6H.
3C = 4-4-0-5.
...3D = Asks min/max.
...3H = NF with 6H.
3DHS = 5 card suit in a 7-5 hand.


2C-2D; 2H-2S (opener have 0--2 hearts);
2NT = Side-suit and short hearts.
...3C = Relay.
......3D = 6+C and 4D.
......3H = 4-1-3-5.
......3S = 4-1-2-6.
......3NT = 4-0-3-6.
......4C = 4-0-2-7.
......4D = 4-1-1-7.
3C = Short spades or 6C no shortness.
3D = 7+C, short hearts or no shortness.
3H = 3-1-3-6.
3S = 4-2-1-6.
3NT = 4-2-0-7.
4C = 7+C, singleton diamond.
4D = 7+C, void diamond.

Not quite sure if above is the best we can get...


2C-2D; 2S-2NT (opener has 3H and 6+C);
3C = Short spades.
3D = 2-3-2-6.
3H = 3-3-1-6.
3S = 4-3-0-6.
3NT = 2-3-1-7.
4C = 3H, 7+C, void diamond.


2C-2D; 2NT-3C (opener has 4H, but not 4-4-0-5);
3D = 6-4, short spades.
3H = 1-4-3-5.
3S = 2-4-1-6.
3NT = 3-4-0-6.
4C = 2-4-0-7.

[straube]

Can't quite remember how we did it (posted somewhere on BBO) but we used

2C-2D, 2H as 0-1 H (which could include your 4135)

Maybe
2S-bal or 4D
2N-spade short, 6C
3C-diamond short, 6C
etc-4H

Seemed better than that. Maybe Foobar has the old notes. Anyway, you might try using 2H as 0-1. All the other steps would promise 6 clubs and you can arrange such so that you always have 3C as a relay ask and also can allow opener's 3C rebid to be forcing (because you can relay break to show at least a 5-2 heart fit).

Side comment is that 5/7s are very rare and I should think they need to be shown at the 4-level.

[Zelandakh]

Kungsgeten, on 2019-August-15, 05:01, said:

Yes, if I remember correctly he plays 1D as wide-ranging (could be wrong here) natural unbalanced, and thus 2C needs to handle 5C and 4M (since he also plays five card majors).

Absolutely correct. The transfer-based scheme came from my frustration with the available relay-based methods for this style of 2♣ opening. Including the (14)35 hands within the 1♦ opening is not really an option for the response structure I use so it was either come up with a system over 2♣ that I could live with or abandon the entire system concept.

In the OP system, I think you are missing a trick in the 2♣ - 2♥; 2♠ - 2NT auction. With 4 hearts and a max you know you have a fit and game here so no reason to keep the bidding below 3NT. Instead of bidding 3♠ with all such hands, how about 3♠ = 4 hearts, max, side void; 3NT = 2=4=2=5, max; 4♣ = 4 hearts, singleton spade, max; 4♦ = 4 hearts, singleton diamond, max? YOu are going to be Dummy (in 4♥) anyway so giving up more information is unlikely to be disastrous.

Overall it looks on the surface that you have sacrificed a fair bit on invitational hands to get the relay structure in. It is difficult to tell just on paper whether you get enough to offset that but I am absolutely certain that being able to exclude some hand types will help out enormously in terms of fitting the relays into the available space. And also worth bearing in mind - this type of 2♣ opening is never going to be a big winner. Your aim in producing a build is to get as close to breaking even as possible. Your 1♦ and 1M openings will typically provide a solid plus and more than compensate providing you can be sure of reaching decently playable contracts here and have systems in place to cope with interference over 1♣.