Is 1C-1S DN unsound?

[awm]

While I agree my system is complex, its mostly the sequences after semi-positives that cause this. Its tricky to maximize your fit finding opportunities while still having relay. 1c-1d is not complicated. Basically opener makes a natural rebid! If this is 1nt we just play systems on. If its 1M then 1nt is GF relay and anything else is DN (and mostly natural). If opener rebids 2x the cheapest step is GF relay and otherwise natural and DN.

 

There is a little work to sort opener's really big hands or help on 1c-1d-1M canape types but these are just little optimizations and not a big deal.

[akhare]

Does your 1C-1D, 1H promise extra values? Like 20+?

 

No, it does not promise extra values and it doesn't need to, because we the same recourse available after 1♣ - 1♦ - 1♥ - 1♠ (DN) as over 1♣ - 1♠ (DN).

 

Note that we can comfortably play 1♠ / 2♣ / 2♦ opposite a DN hand after 1♣ - 1♦, which isn't possible over 1♣ - 1♠. Furthermore, opener can bid 1N over 1♦ with true (min) balanced hands instead being coerced into the 1N bid with non-conforming shapes after 1C - 1S. Granted, opener might face the same conondrum after hearing 1S over 1H, but this creates an extra sequence which isn't otherwise possible.

 

Note that like in Adam's system, all of opener's rebids except for 1♥ are *natural*, but responder can still fully relay the hands using the same symmetric scheme.

[straube]

No, it does not promise extra values and it doesn't need to, because we the same recourse available after 1♣ - 1♦ - 1♥ - 1♠ (DN) as over 1♣ - 1♠ (DN).

 

Note that we can comfortably play 1♠ / 2♣ / 2♦ opposite a DN hand after 1♣ - 1♦, which isn't possible over 1♣ - 1♠. Furthermore, opener can bid 1N over 1♦ with true (min) balanced hands instead being coerced into the 1N bid with non-conforming shapes after 1C - 1S. Granted, opener might face the same conondrum after hearing 1S over 1H, but this creates an extra sequence which isn't otherwise possible.

 

Note that like in Adam's system, all of opener's rebids except for 1♥ are *natural*, but responder can still fully relay the hands using the same symmetric scheme.

 

But if it doesn't promise extra values, after 1C-1D, 1N+ handles the semipositives? Your structure listed them as GF. Even if opener tries to break relay, we will be too high much of the time.

[akhare]

But if it doesn't promise extra values, after 1C-1D, 1N+ handles the semipositives? Your structure listed them as GF. Even if opener tries to break relay, we will be too high much of the time.

 

There are no SP hands in the 1♦ response. The 1♦ response contains only true DN hands (0-2 QP) OR some GF hands with ♥. The goal behind partioning the hand strength *and* limiting the hand types in the two way response is to make it resilient in the case of contested auctions.

 

Ergo, all of responder's 1N+ bids show GF hands (with hearts).

 

All other GF and SP hands respond with a bid other than 1♦.

[straube]

I see. So what is the rest of your structure? What are the responses to 1C?

[akhare]

I see. So what is the rest of your structure? What are the responses to 1C?

 

Here's a proposal -- there's likely room for some optimization, but this a good starting point:

 

1♦: DN (0-2) OR unbal GF with ♥ and another

....1S: DN

....1N: H+S / H

....2C: H+C

....2D: Three suited

....2H+: H+D

 

1♥: GF with ♠ / bal / three suited

.....1N: S+C / S

...........2D: Spades

...........2H+: S+C

.....2C: Balanced hands

.....2D: Three suited (see note below)

.....2H+: S+D

 

1♠: SP, including bal, one or two suited with ♥/minors, minors; play structure of choice

 

1N: SP; 5+ ♠ and another

.....2♦: 5♠, 4+H

.....2♥: 5+ ♠ and 4+♣

.....2♠: 5+ ♠ and 4+♦

 

2♣: GF, minors

2♦: GF, clubs

2♥: SP; single suited with ♠

2S+: GF with diamonds

 

Note that it's possible to play the immediate 2H as GF three suited and use the "extra" 2D in the 1C - 1H - 1S to show balanced hands without a major.

 

In this case, the 1N SP response can be tweaked to show 2D as S+H, 2H as single suited with S and 2S as S+m.

[straube]

That looks interesting. I would think to combine the SPs back into 1H. 1H has the same power as 1S and 1N together (the current allocation of SPs) but allows opener to break relay with 1N, etc. Without having much time to think about it...

 

1D-H+ or 3-suited Ms or DN

1H-SP

1S-bal,C/D,

.....1N-relays

..........2C-bal, major

...............S/H

..........2D-bal, no major

...............D

..........2H-C/D

.....2C-S/C

.....2D-S

.....2H-S/D

1N-S, S/C

2C-S/D

2D-C

2H-3-suited ms

2S-D

 

Not many reverse relays and I kind of hate burying the hearts despite the likelihood of opener rebidding 1H.

[akhare]

That looks interesting. I would think to combine the SPs back into 1H. 1H has the same power as 1S and 1N together (the current allocation of SPs) but allows opener to break relay with 1N, etc. Without having much time to think about it...

 

1D-H+ or 3-suited Ms or DN

1H-SP

1S-bal,C/D,

.....1N-relays

..........2C-bal, major

...............S/H

..........2D-bal, no major

...............D

..........2H-C/D

.....2C-S/C

.....2D-S

.....2H-S/D

1N-S, S/C

2C-S/D

2D-C

2H-3-suited ms

2S-D

 

Not many reverse relays and I kind of hate burying the hearts despite the likelihood of opener rebidding 1H.

 

This scheme looks very good to me and I think it should be definitely be an improvement over 1♠ DN.

[Free]

It's all great if opps don't interfere. But then isn't every system? B-)

[straube]

I just tallied 100 hands and there were only 20 1D responses. I think that RobF gets more 1D responses because his DN is likely stronger/wider ranging than ours and because he treats 5332s as single-suited.

 

So Free, what are you particularly concerned about? I know you don't like the 1H semipositive. How about the 1D response? I would rather it showed spades or a DN and feel like that this response would be met with lots of overcalls....because we are either weak or because we may misjudge our heart fit. I wonder how often 1D makes them think twice about overcalling hearts.

 

What do you think of this structure, Adam? I like yours better, but at least it seems simpler.

[hrothgar]

For what its worth...

 

Back in the weird old days when I was originally trying to convince Marston that the traditional MOSCITO response structure to strong club openings should be modified we considered using

1♣ - (P) - (1♦) to show either a double negative or a game force. Ultimately, Marston decided that he preferred using 1♣ - (P) - 1♠ as a double negative.

 

As I recall, two different issues effected the decision

 

1. Marston really liked the option to incorporate an early reverse relay to limit the strength of the strong club opening.

 

Suppose the (uncontested) auction starts

 

1♣ - 1♦

 

The strong club opener can either

 

Bid 1♥ to ask for responder's shape

Bid 1♠, reversing the relay and showing shape

 

This initial reverse relay limits the strength of the strong club opener. At this point in time, the relay captain is well positioned to understand whether the two hands should be investigating slam (in which case its entirely appropriate to continue the relays). Alternatively, if the relay captain thinks that game is the limit you're at a nice low level to either bash to game or transition to natural bidding and sanely investigate whether 3N is a good contract.

 

The resulting structure is simple, practical, and frequent.

 

2. Back during his forcing pass days, Marston used a variety of different ferts ranging from 1♥ to 2♣. He had plenty of experience with high level bids that show bad hands and say little/nothing about strength and felt that the 1♠ double negative was quite playable.

[whereagles]

I like 1♥ as the negative (or DN if you prefer). That leaves room for transfers, e.g.

 

1♠ = balanced, unlimited. Resp uses system on.

1NT...2♥ = transfer. Resp fills transfer (means: "may not have fit... continue at your own risk") or bids his suit with some values.

2♠ = 5S-4H, limited to ~21 (a hand that's hard to bid via transfers).

2NT...3♥ = transfer, but good 1-suiter. Resp bids a side A/K if he's lucky to have one.

3♠ = 5S-4H, game force.

[akhare]

For what its worth...

 

Back in the weird old days when I was originally trying to convince Marston that the traditional MOSCITO response structure to strong club openings should be modified we considered using

1♣ - (P) - (1♦) to show either a double negative or a game force. Ultimately, Marston decided that he preferred using 1♣ - (P) - 1♠ as a double negative.

 

As I recall, two different issues effected the decision

 

1. Marston really liked the option to incorporate an early reverse relay to limit the strength of the strong club opening.

 

That's an interesting insight.

 

At that time, did you also discuss the division of responses between SP and GF hands? What do you think are the tradeoffs of SP structure like SCREAM that allocates a single bid for all SP (1♥)responses and Moscito?

[hrothgar]

At that time, did you also discuss the division of responses between SP and GF hands? What do you think are the tradeoffs of SP structure like SCREAM that allocates a single bid for all SP (1♥)responses and Moscito?

 

My explicit goal was showing shape with the semi-positive hand types

 

This might sound redundant, but if the auction starts 1♣ - 1♦ (GF) we have a game force established.

Having a forcing pass established significantly changes the cost/benefit analysis for intervening

 

1. It's much easier for us to penalize the opponents if they intervene

2. Its easier for us to shape shape / etc if the opponents intervene

 

With the semi positive hands, I wanted to immediately show shape (with an emphasis on showing 5 card majors)

 

1. If we've already forced the auction to 1NT+ interference becomes much more risky

2. Ideally, if responder has show a semi-positive hand with a 5 card major we can quickly bash to good games forcing the opponents to defend blindly

 

[Harkening back to an earlier thread... This is why I like to play artificial systems. I don't just know "what" I am supposed to bid, I can explain why the system is designed the way that it is...]

[akhare]

 

With the semi positive hands, I wanted to immediately show shape (with an emphasis on showing 5 card majors)

 

1. If we've already forced the auction to 1NT+ interference becomes much more risky

2. Ideally, if responder has show a semi-positive hand with a 5 card major we can quickly bash to good games forcing the opponents to defend blindly

 

I think this is important point to consider as well in defining the SP responses to 1♣.

 

IMO, it's possible to straddle the "best of both worlds" in a scheme that uses a two way 1♦ response and allocating *some* immediate responses for SP hands with the majors.

[hrothgar]

I think this is important point to consider as well in defining the SP responses to 1♣.

 

IMO, it's possible to straddle the "best of both worlds" in a scheme that uses a two way 1♦ response and allocating *some* immediate responses for SP hands with the majors.

 

Once again, please don't underestimate the value of have a forcing pass established following

 

1♣ - (P) - 1♦

 

For whatever reason, people like walking into that auction

 

"The opened 1♣! They have a strong hand and showed nothing about shape! Just wait until partner bids 2♠"

"Damn, partner passed!"

"What's this!!! They just bid 1♦ its another strong bid that shows nothing about shape! I can't bid spades, but I can still bid 2♥ and screw them and their precious little relays"

"OOH!!! A red card, I am so scared!"

"Maybe -800 won't score up so bad... And they missed their cold 3NT!!!"

[akhare]

Once again, please don't underestimate the value of have a forcing pass established following

 

1♣ - (P) - 1♦

 

For whatever reason, people like walking into that auction

 

Absolutely agree with you regarding the value of FP that's established following a GF response. There's no doubt that one of the tradeoffs of playing a two way 1♦ is the loss of the FP.

 

The question is whether this loss can is offset by (subjective) gains elsewhere. For the design goals I had in mind, the answer seems like a yes, but as always, the real proof lies in actually trying it out...

[whereagles]

Using 1C-1D as GF is certainly playable, but it leaves both RHO with an easy butt-in at low level when both hands have shown no distrubution.

 

For that reason would prefer a GF response to show a suit.

[straube]

An important thing that I like about 1S as DN is that it brings this hand into the auction. Responder may not have high cards, but he can have distribution. Say the auction goes...

 

1C P 1S (2D)

P P ?

 

It's nice for responder to be able to compete 2H with xx Qxxxx xx xxxx without promising much. Yes, it may be wrong, but we rate to have half the deck and letting them play 2D may also be wrong.

 

Or responder could have xxxx xxx x xxxxx and then he might double. Opener ought not pass unless he sees a set by his own hand, but he just might have that. Opener's own double would also be takeout, so whose to say he can't have a primary diamond suit that has no bid over the overcall? On more days of the week, he'll have something like AKJx KQx Kxxx Qx and will bid 2S. I don't think there's a way to compete here if responder hasn't already limited his hand.

 

My example hands might be marginal for whether responder wants to act, but one could come up with something more clear-cut and the principle remains the same.

[hrothgar]

Using 1C-1D as GF is certainly playable, but it leaves both RHO with an easy butt-in at low level when both hands have shown no distrubution.

 

For that reason would prefer a GF response to show a suit.

 

As I recall, we tended to get pretty good scores when folks were dumb enough to butt in after 1♣ - (P) - 1♦

 

(Not as good as when they'd butt in after out 2♦ or 2♥ openings, but we'd still be in a nice position to hammer them...)

[akhare]

An important thing that I like about 1S as DN is that it brings this hand into the auction. Responder may not have high cards, but he can have distribution. Say the auction goes...

 

1C P 1S (2D)

P P ?

 

 

This is a valid point, but I think one would be hard pressed to justify this on the basis of frequency. I can't seem to recall holding a single DN hand that took action after LHO's overcall after 1♣ - 1♠ - (blah) - P - (P).

[whereagles]

As I recall, we tended to get pretty good scores when folks were dumb enough to butt in after 1♣ - (P) - 1♦

 

You're bound to have good scores when people do dumb things :) LOL

[Zelandakh]

I do not think 1S as a DN is unsound. You get some plusses and some minuses. That said I am not yet convinced it is optimal. As you know I have a strong club system where the opening 1C bid can be made with a flat 15 which puts me in a similar situation to you on the percentage of hands in the GF/SP/DN ranges. For me 1D as 0-8 works just fine after which I just ditch relays and use the extra space to split hand types up tightly enough to make natural bidding work. I am sure I lose something by not being able to relay SPs, I am just not convinced it is enough.

 

When I was designing the system I did consider a split range response structure such as Adam uses. I do not really see any problem with it as "DN or GF" is no more difficult to use, and arguably simpler, than the traditional "DN or SP". That said, it did not fit the way my system is built so I did not pursue it. It makes more sense if you (almost) always relay after a positive (I only relay with 18+) since now you really are not losing very much. I prefer this in general to the 1S DN but you always have to play-test for a specific system to see which works in context.