BBO Discussion Forums: Is 1C-1S DN unsound? - BBO Discussion Forums

Jump to content

  • 3 Pages +
  • 1
  • 2
  • 3
  • You cannot start a new topic
  • You cannot reply to this topic

Is 1C-1S DN unsound?

#21 User is offline   akhare 

  • PipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 1,261
  • Joined: 2005-September-04
  • Gender:Male

Posted 2012-January-05, 11:14

View Poststraube, on 2012-January-05, 07:49, said:

Generally speaking, I think 2-way bids are problematic because partner can't bid very high from that 2-way bid without getting in the way of one or the other type of hand. When 2-way bids are successful, they are usually accompanied by a great deal of complication.


I disagree -- two way bids can be complicated, but that's a deliberate design choice rather than an inherent trait.

straube said:

1) We play that opening 2C to show an opening hand with 6 clubs followed by 2D is either a constructive hand with hearts OR any GF hand that wants to relay partner's hand. We had to devise a whole new relay structure to handle this. Opener's first rebid (2H) showed 0-1 heart, second response showed 2 hearts, and higher responses showed 3 hearts. Again, a whole new relay structure and relay breaks, too. So imo, it's successful but complicated.


Another example of complication by a deliberate design choice.

Quote

I think it would be difficult to play 1C-1D as 0+ which it would be if it were say 0-7 OR 8+ with hearts or something else like that. For example, opener might try to show extra strength on some hands in case partner has 0-7, but that would be the wrong approach when partner turned out to have GF hearts.

Hmm..., I don't see how opener's rebids over 1 - 1 can be more difficult than over 1 - 1 (DN).

How about stating exactly what opener rebid complications you forsee over a response structure that defines 1 as DN (0-2 SPs) or GF with ?

As I see it, opener's rebids are vastly superior to bidding over 1 - 1 and allow better partioning of NT ranges as well.

1H (general ask):
......1S: Confirms DN
.............Deploy 1S response structure of choice
......1N+: Blah, GF
1S: Natural, single suited or two suited with a minor
....1N: GF relay
1N: (Strictly balanced)
2C: (Natural, single suited)
....2H: GF relay
2D: (Natural, single suited)
....2H: GF relay
foobar on BBO
0

#22 User is offline   wclass___ 

  • PipPipPipPip
  • Group: Full Members
  • Posts: 431
  • Joined: 2008-November-02

Posted 2012-January-05, 11:34

I'm very sure that ''0-7 type'' is the best.

I am also sure that ''GF'' shouldn't be strictly GF. Structure can gain a lot by being able to stop below game in misfit hands. e.g. if one plays 1-1 as strictly GF with 5+i would mush rather change it to like 7+ with 5+.

"too frequent an occurrence (for us it would be 65% or so), bogging down continuations and..." - 65% is really a lot. But i will shortly repeat myself and say that % is not everything that counts.
''leaves the partnership vulnerable to RHO action.'' - I think this is untrue, i have written my reasoning for this on these forums, but probably my poor english didn't convince you. Posted Image
Seeking input from anyone who doesn't frequently "wtp", "Lol" or post to merely "Agree with ..." --sathyab
0

#23 User is offline   Free 

  • mmm Duvel
  • PipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 10,728
  • Joined: 2003-July-30
  • Gender:Male
  • Location:Belgium
  • Interests:Duvel, Whisky

Posted 2012-January-05, 13:13

View Poststraube, on 2012-January-04, 20:46, said:

What I don't like about multi-Landy is that it threatens to "drop" responder prematurely. Say it goes 1C-1S, 2C-2H. That shows 4 hearts, right? So opener passes and responder has 6 hearts and the partnership has missed a 10-cd fit.

2 doesn't show 4+, it only shows preference. If you have an invite, you can start with 2 (...-2-2M-3M, ...-2-2-2 or ...-2-2-3). With a 6 card suit responder probably won't bid 2, but he'll stay low just in case opener has a strong hand.

After the multi, you can use the paradox bidding to keep opener from passing when a distributional game is possible.

Also note that after each of these bids (also 2M) responder can bid 2NT forcing!

View Poststraube, on 2012-January-04, 20:46, said:

I also don't like if it goes 1C-1S, 2C-2H, 2N (which I assume shows 21-22 or so)-3H and opener has AKxx Q AKxx AKxx and responder has xx Jxxxx xx xxxx.

That's a problem everyone has if you're considering a 4441 as balanced and responder transfers. So quite irrelevant to the discussion imo. Nobody says responder has to transfer... ;)

View Poststraube, on 2012-January-04, 20:46, said:

The "being dropped" issue is compounded when responder has a semipositive hand. We have occasional semipositive hands that always intend to game force...they are just lacking in the QP department.

Well, missing 2C with x AKxx AQx AJTxx is not the worse thing about 1S as DN, but I don't really like having to rebid 3m after 1C-1H. With a six-cd suit, I rate to make, but the bid puts a lot of pressure on responder when he wants to show a 5 or 6-cd major...especially when he wants to force to game with or without a club fit.

You can't have it all. Either opener describes his hand and responder bids some playable part score, or responder describes his hand and opener bids some playable part score. With the multi-landy scheme opener can describe all Major-oriented hands (which is quite important imo). With minor-oriented hands he'll need to be creative and flexible. Usually 1NT is a good choice if it's pretty balanced, after which responder can still show his hand type and strength. After each 2-level bid, responder has options to keep the bidding open, so I don't see where you get the idea of us "being dropped". I rather prefer this way than having opener use another relay, wasting more space, just to let responder show his hand.

It's important to realize that with this scheme we almost always have a reasonable fit. We'll find a playable part score, we can find distributional Major games, and we can force the auction even after a semi positive.
"It may be rude to leave to go to the bathroom, but it's downright stupid to sit there and piss yourself" - blackshoe
0

#24 User is offline   straube 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 4,082
  • Joined: 2009-January-18
  • Gender:Male
  • Location:Vancouver WA USA

Posted 2012-January-05, 15:15

Thanks for explaining. So what does 1C-1S, 2C-2S, 2N show? And how about 1C-1S, 2C-2S, 3S? What I'm getting at is if the 2N rebid shows a balanced 21-22 point hand and whether opener will raise partner's major with four trump or not. I had thought that the 2C bid was designed to pick up 4-4 major suit fits as well as show 5/4 in the majors and now I'm thinking it must only serve the latter purpose.

For that difficult hand I gave AKxx Q AKxx AKxx opposite xx Jxxxx xx xxxx our bidding would go 1C-1S, 2C-2D(hearts), 2H-22-23 "balanced" with doubleton or singleton heart.
0

#25 User is offline   straube 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 4,082
  • Joined: 2009-January-18
  • Gender:Male
  • Location:Vancouver WA USA

Posted 2012-January-05, 15:36

akhare said:


How about stating exactly what opener rebid complications you forsee over a response structure that defines 1 as DN (0-2 SPs) or GF with ?

As I see it, opener's rebids are vastly superior to bidding over 1 - 1 and allow better partioning of NT ranges as well.

1H (general ask):
......1S: Confirms DN
.............Deploy 1S response structure of choice
......1N+: Blah, GF
1S: Natural, single suited or two suited with a minor
....1N: GF relay
1N: (Strictly balanced)
2C: (Natural, single suited)
....2H: GF relay
2D: (Natural, single suited)
....2H: GF relay



Does your 1C-1D, 1H promise extra values? Like 20+?
0

#26 User is online   awm 

  • PipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 8,375
  • Joined: 2005-February-09
  • Gender:Male
  • Location:Zurich, Switzerland

Posted 2012-January-05, 15:40

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.
Adam W. Meyerson
a.k.a. Appeal Without Merit
0

#27 User is offline   akhare 

  • PipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 1,261
  • Joined: 2005-September-04
  • Gender:Male

Posted 2012-January-05, 16:51

View Poststraube, on 2012-January-05, 15:36, said:

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.
foobar on BBO
0

#28 User is offline   straube 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 4,082
  • Joined: 2009-January-18
  • Gender:Male
  • Location:Vancouver WA USA

Posted 2012-January-05, 17:28

View Postakhare, on 2012-January-05, 16:51, said:

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.
0

#29 User is offline   akhare 

  • PipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 1,261
  • Joined: 2005-September-04
  • Gender:Male

Posted 2012-January-05, 17:41

View Poststraube, on 2012-January-05, 17:28, said:

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.
foobar on BBO
0

#30 User is offline   straube 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 4,082
  • Joined: 2009-January-18
  • Gender:Male
  • Location:Vancouver WA USA

Posted 2012-January-05, 17:49

I see. So what is the rest of your structure? What are the responses to 1C?
0

#31 User is offline   akhare 

  • PipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 1,261
  • Joined: 2005-September-04
  • Gender:Male

Posted 2012-January-05, 18:40

View Poststraube, on 2012-January-05, 17:49, said:

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.
foobar on BBO
0

#32 User is offline   straube 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 4,082
  • Joined: 2009-January-18
  • Gender:Male
  • Location:Vancouver WA USA

Posted 2012-January-05, 20:18

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.
0

#33 User is offline   akhare 

  • PipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 1,261
  • Joined: 2005-September-04
  • Gender:Male

Posted 2012-January-05, 22:04

View Poststraube, on 2012-January-05, 20:18, said:

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.
foobar on BBO
0

#34 User is offline   Free 

  • mmm Duvel
  • PipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 10,728
  • Joined: 2003-July-30
  • Gender:Male
  • Location:Belgium
  • Interests:Duvel, Whisky

Posted 2012-January-06, 00:14

It's all great if opps don't interfere. But then isn't every system? B-)
"It may be rude to leave to go to the bathroom, but it's downright stupid to sit there and piss yourself" - blackshoe
0

#35 User is offline   straube 

  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 4,082
  • Joined: 2009-January-18
  • Gender:Male
  • Location:Vancouver WA USA

Posted 2012-January-06, 02:37

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.
0

#36 User is offline   hrothgar 

  • PipPipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 15,488
  • Joined: 2003-February-13
  • Gender:Male
  • Location:Natick, MA
  • Interests:Travel
    Cooking
    Brewing
    Hiking

Posted 2012-January-06, 08:49

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.
Alderaan delenda est
0

#37 User is offline   whereagles 

  • PipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 14,900
  • Joined: 2004-May-11
  • Gender:Male
  • Location:Portugal
  • Interests:Everything!

Posted 2012-January-06, 10:13

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.
0

#38 User is offline   akhare 

  • PipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 1,261
  • Joined: 2005-September-04
  • Gender:Male

Posted 2012-January-06, 11:39

View Posthrothgar, on 2012-January-06, 08:49, said:

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?
foobar on BBO
0

#39 User is offline   hrothgar 

  • PipPipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 15,488
  • Joined: 2003-February-13
  • Gender:Male
  • Location:Natick, MA
  • Interests:Travel
    Cooking
    Brewing
    Hiking

Posted 2012-January-06, 12:34

View Postakhare, on 2012-January-06, 11:39, said:

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...]
Alderaan delenda est
0

#40 User is offline   akhare 

  • PipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 1,261
  • Joined: 2005-September-04
  • Gender:Male

Posted 2012-January-06, 14:35

View Posthrothgar, on 2012-January-06, 12:34, said:


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.
foobar on BBO
0

  • 3 Pages +
  • 1
  • 2
  • 3
  • You cannot start a new topic
  • You cannot reply to this topic

2 User(s) are reading this topic
0 members, 2 guests, 0 anonymous users