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MOSCITO competitive auctions How does opener resolve major/minor suit length?

#1 User is offline   akashc 

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Posted 2021-April-26, 02:17

I'm having difficulty understanding how a MOSCITO partnership deal with higher level interference after an opening that shows a major suit. Assume that opener has shown 4+H (it doesn't matter whether that is via a 1D transer opening or a natural 1H), and then LHO bids 2S.

My first question is what should responder do with a balanced inv+ hand, both with and without 3c H support? Secondly, if responder makes a negative double, how does opener distinguish between 5/6M4m and 4M5/6m hands? I think the answer must depend on what responder does with 3c support, but I'm not sure what the best unified approach is.
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#2 User is offline   foobar 

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Posted 2021-April-26, 13:57

akashc@: The emphasis of Moscito is on "quick in, quick out" auctions. To that end, there's loss of precision in competitive auctions, and it can be difficult to tell the relative lengths of 5-4 suits in auctions like 1 (hearts) - (2) - X (takeout) - 3m. Note that the situation isn't that different from a 4-card major auction like 1 - (2) - X, except that Moscito openings can be lighter, and are limited.

Perhaps, it's best to start off my asking what the X promises in terms of strength?
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#3 User is offline   akashc 

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Posted 2021-April-27, 00:08

@foobar: I hadn't realized how far the "quick in, quick out" philosophy extended. Maybe Moscito isn't for me!

I don't agree with the similarity to 4 card majors, at least for the flavor of Acol that I play: 1 - (2) - X (takeout) - (P) - 3m almost always shows 5+c in hearts and 4+c in the minor.

I don't know what the double should promise. I'm interested in what a good combination of meanings for responder's and opener's bids should mean. My naive assumption was the double would be inv+ (maybe a bit shaded).
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#4 User is offline   nullve 

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Posted 2021-April-27, 02:37

I've never played Moscito, but here is an adaption of stuff that is not unheard of in 2/1-like systems:

1-(2)-?:

P = NAT NF, includes BAL INV with either 3-5S2H, 33(52) or 4-5S3H*
...P = (most hands with) 3+S5-H5-D5-C (yes, could miss game opposite BAL INV)
...X = takeout
......P = LoTT-based
......2N = Good/Bad, here with any non-INV hand that can't pass
.........3 = P/C
.........3 = ELC
.........(...)
......3-3 = NAT INV
......(...)
...2N = Good/Bad
......3 = P/C
.........P = MIN, 4(+)H6+C
.........3 = MIN, 4(+)H6+D
.........3 = MIN, 6+ H
.........(...)
......(...)
...3m = MAX, 4(+)H(5)6+m
...3 = MAX, 6(+) H
...(...)
X = takeout, includes BAL INV with either 2S3H or 3H(433)*
...P = 4+ S (including any 44(41)?)
...2N = Good/Bad
......3 = P/C
.........P = MIN, 4H5+C
.........3 = MIN, 4H5+D
.........3 = MIN, 5+ H
.........(...)
......3 = ELC
......(...)
...3m = MAX, 4(+)H5+m
...3 = MAX, 5(+) H
...(...)
2N = INV+ 4c+ raise
3m = Switch (3 could be played as INV+)
3 = competitive 4c+ raise
(...)

* I think Responder should double even on INV hands with 4333 shape unless prepared to pass a reopening double by partner.
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#5 User is offline   hrothgar 

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Posted 2021-April-27, 05:25

I think that folks are drawing inspiration from the wrong places here. More specifically, I don't think that the methods that people who play 2/1 use after the auction

1! - (2!)

are going to be particularly helpful. If, however, if you are a standard auction like

1! - (P) - 1! - (2!)

That's suddenly a lot more interesting since that original 1!H response looks a lot more like a MOSCITO 1 opening.

From my perspective, there are a couple decent sources about handling competition playing 4CM.

The first is Robson and Segal.
The second is Major Suit bidding the Scanian Way.

Both emphasize the needs to be able to quickly differentiate between hands with 3 card support and 4 card support.

So, assuming that you are playing in a serious partnership, I suspect that its best to use something like the following

X = Negative double
2N = 3 card Heart support
3 = Natural + Forcing
3 = Good raise to 3
3 = Competitive raise with 4 card support

After 2N, 3m is to play and typically shows a 4 card major and a longer minor

After X, 3m is also to play, however, this could be a 5M / 4m
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#6 User is offline   foobar 

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Posted 2021-April-27, 09:51

View Postakashc, on 2021-April-27, 00:08, said:

@foobar: I hadn't realized how far the "quick in, quick out" philosophy extended. Maybe Moscito isn't for me!

I don't agree with the similarity to 4 card majors, at last for the flavor of Acol that I play: 1 - (2) - X (takeout) - (P) - 3m almost always shows 5+c in hearts and 4+c in the minor.

I don't know what the double should promise. I'm interested in what a good combination of meanings for responder's and opener's bids should mean. My naive assumption was the double would be inv+ (maybe a bit shaded).


The reference to "quick in, quick out" is a little misplaced in the context of this specific auction, but it does apply to other situations like 1 () - (2/2-1), where you may want to explore NFBs for example.

For this particular auction, X should indeed promise at least invite+. Richard's suggestion of using 2N+ as a raise, with 3-level GF bids makes sense.
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#7 User is offline   awm 

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Posted 2021-April-27, 10:20

View Posthrothgar, on 2021-April-27, 05:25, said:

So, assuming that you are playing in a serious partnership, I suspect that its best to use something like the following

X = Negative double
2N = 3 card Heart support
3 = Natural + Forcing
3 = Good raise to 3
3 = Competitive raise with 4 card support

After 2N, 3m is to play and typically shows a 4 card major and a longer minor

After X, 3m is also to play, however, this could be a 5M / 4m


It seems like it would be nice to have a natural forcing 3 bid available. Perhaps the strong four-card heart raise can be added to either the double or 2NT bid. Otherwise this looks fine to me; when playing a four-card major system with possible canape it seems really important to have a "strong three-card raise" available in a lot of competitive auctions.
Adam W. Meyerson
a.k.a. Appeal Without Merit
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#8 User is offline   hrothgar 

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Posted 2021-April-27, 10:32

View Postawm, on 2021-April-27, 10:20, said:

It seems like it would be nice to have a natural forcing 3 bid available. Perhaps the strong four-card heart raise can be added to either the double or 2NT bid. Otherwise this looks fine to me; when playing a four-card major system with possible canape it seems really important to have a "strong three-card raise" available in a lot of competitive auctions.


I had thought to have the strong Diamond bid in the initial double

I THINK that its more useful to be able to clarifying 4 card heart support immediately than show the Diamond suit. I could easily be convinced otherwise.
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#9 User is offline   Zelandakh 

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Posted 2021-April-27, 12:34

View Posthrothgar, on 2021-April-27, 05:25, said:

X = Negative double

After X, 3m is also to play, however, this could be a 5M / 4m

After the negative X, is it possible to use 2NT to separate 4M5 hands from 5M4 ones perhaps? I am not sure precisely which hands are included here to know how you are planning on using this sequence.
(-: Zel :-)

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#10 User is offline   nullve 

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Posted 2021-April-27, 13:47

View Posthrothgar, on 2021-April-27, 05:25, said:

I think that folks are drawing inspiration from the wrong places here. More specifically, I don't think that the methods that people who play 2/1 use after the auction

1! - (2!)

are going to be particularly helpful. If, however, if you are a standard auction like

1! - (P) - 1! - (2!)

That's suddenly a lot more interesting since that original 1!H response looks a lot more like a MOSCITO 1 opening.

Agree.

View Posthrothgar, on 2021-April-27, 05:25, said:

From my perspective, there are a couple decent sources about handling competition playing 4CM.

The first is Robson and Segal.

The second is Major Suit bidding the Scanian Way.

Both emphasize the needs to be able to quickly differentiate between hands with 3 card support and 4 card support.
So, assuming that you are playing in a serious partnership, I suspect that its best to use something like the following

X = Negative double
2N = 3 card Heart support
3 = Natural + Forcing
3 = Good raise to 3
3 = Competitive raise with 4 card support

After 2N, 3m is to play and typically shows a 4 card major and a longer minor

After X, 3m is also to play, however, this could be a 5M / 4m

But on p. 200 of their book, Robson-Segal recommend using "Lebensohl 2NT" on

K65
Q742
A653
K3

over

1-(P)-1-(2).

So X, whether "support" (promising 3 H) or "takeout" (focusing more on the fourth suit and not absolutely guaranteeing 3 H), would presumably be the closest thing to a 3c raise in this position.
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#11 User is offline   hrothgar 

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Posted 2021-April-27, 14:05

View PostZelandakh, on 2021-April-27, 12:34, said:

After the negative X, is it possible to use 2NT to separate 4M5 hands from 5M4 ones perhaps? I am not sure precisely which hands are included here to know how you are planning on using this sequence.


MOSCITO used an 11+ - 14 HCP 1NT opening. So the one thing that the 2N rebid doesn't need to show is a balanced hand with the Spade stopper.

There are a number of possible schemes that 2NT might show.
However, I don't think that clarifying major suit length is particular useful.

I think that any of the following would work better

1. Using 3m as natural with 2N as some kind of good / bad scramble
2. Use 2N as natural, showing a spade stopper and suggesting 3N
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#12 User is offline   nullve 

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Posted 2021-April-28, 05:10

It seems to follow from the discussion in 'A system note' (p. 33 onwards), in particular the definition of class (s.3) systems on p. 33 and example (a) on p. 38, that Robson-Segal would not play any 3c raise over 1*-(2).
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#13 User is offline   hrothgar 

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Posted 2021-April-28, 07:39

View Postnullve, on 2021-April-28, 05:10, said:

It seems to follow from the discussion in 'A system note' (p. 33 onwards), in particular the definition of class (s.3) systems on p. 33 and example (a) on p. 38, that Robson-Segal would not play any 3c raise over 1*-(2).


Robson and Segal define

s.1 as 5 card major systems
s.2 as 4 card major systems with a weak NT
s.3 as 4 card major systems with a strong NT

MOSCITO is most certainly not s.1 or s.3. It technically qualifies as s.2, however, you can't hold a strong NT hand (all of these get opened 1)

I think that this distinction is significant enough that being able to show the 3 card raise is warranted.

I will note that R & S most certainly do differentiate between 3 and 4 card raises after simple overcalls.
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#14 User is offline   nullve 

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Posted 2021-April-28, 08:02

Yes, sorry. MOSCITO is superficially a (s.2) system, but

Robson & Segal said:

The problem system, in this context, is (s.3) - not that popular any longer amongst duplicate players, but still played as standard in many rubber-bridge clubs, particularly in Britain, and part of the once popular ‘Blue Club’. The point is that if you play four-card majors and a strong no-trump, you open a lot of (often rather weak) balanced hands 1♥ and 1♠ - that is the main advantage in playing the system! It is thus most unwise, in responding to such an opening, to assume partner has more than four cards. Of course, much of the time partner will hold at least a five-card suit. Thus, playing (s.3), you are handicapping yourself to a certain extent in the competitive auction when facing a 1♥ or 1♠ opening, though the compensation of being able to open one-major so often might well be thought adequate

So I suspect they would have put MOSCITO in the same category as Blue Club if they had thought about it.
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#15 User is offline   hrothgar 

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Posted 2021-April-28, 08:41

Here's the rub...

MOSCITO shows a 4 card major extremely frequently, but it's almost never a weak balanced hand.

It's neither fish nor fowl.
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#16 User is offline   DavidKok 

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Posted 2021-April-28, 12:16

View Postnullve, on 2021-April-27, 13:47, said:

But on p. 200 of their book, Robson-Segal recommend using "Lebensohl 2NT" on

K65
Q742
A653
K3

over

1-(P)-1-(2).

So X, whether "support" (promising 3 H) or "takeout" (focusing more on the fourth suit and not absolutely guaranteeing 3 H), would presumably be the closest thing to a 3c raise in this position.
I personally think this is a, if not the, classic example for the Good/Bad NT.
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#17 User is offline   nullve 

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Posted 2021-April-28, 12:51

View PostDavidKok, on 2021-April-28, 12:16, said:

I personally think this is a, if not the, classic example for the Good/Bad NT.

Agree.
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#18 User is offline   foobar 

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Posted 2021-April-28, 15:25

View Posthrothgar, on 2021-April-28, 08:41, said:

Here's the rub...

MOSCITO shows a 4 card major extremely frequently, but it's almost never a weak balanced hand.

It's neither fish nor fowl.

Maybe an insect with an alternative spelling :D.
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#19 User is offline   pilun 

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Posted 2021-May-01, 07:20

This is what we do:

We always have two ways to raise to the 3-level after their 2x overcall - shapely and invitational.
Usually there is a cue raise, so

1 - (2) - 3 = shapely, 3 = inv+, both 4-card support.

Invitational hands with three trumps start with double, then usually convert to hearts. Normal stuff.

It's different when there is no cue raise to the 3-level:

1 - (2) - 3 = shapely, 2NT = limit+, 4-card support.

After a negative double, the main issue is resolving opener's 5-4, 4-5 and 4-4 shapes.
If they overcall 2M and partner doubles, we play opener's 2NT as SCRAMBLING. The classic case is 4333. This is not to say that 3/ would show five.
After all, responder has suggested minors. It would be churlish not to bid one, though maybe not with four small.
There is also the option to convert doubler's 3 to 3, suggesting 5-4.

In our style, opener's 1 denies four spades, which gives more options to both partners. After

1 - (2)

responder doesn't need double to check for the non-existent 4-4 spade fit. Thus double is often FIVE spades OR a 3-cd limit raise.
Likewise, opener can bid 2 happily over partner's double, rather than nervously, as would be the case if 1 did not deny spades.

Here is the current link to the book

https://ebooksbridge...products_id=776
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#20 User is offline   pilun 

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Posted 2021-May-02, 01:21

View Posthrothgar, on 2021-April-27, 05:25, said:

I think that folks are drawing inspiration from the wrong places here. More specifically, I don't think that the methods that people who play 2/1 use after the auction

1! - (2!)

are going to be particularly helpful. If, however, if you are a standard auction like

1! - (P) - 1! - (2!)

That's suddenly a lot more interesting since that original 1!H response looks a lot more like a MOSCITO 1 opening.

From my perspective, there are a couple decent sources about handling competition playing 4CM.

The first is Robson and Segal.
The second is Major Suit bidding the Scanian Way.

Both emphasize the needs to be able to quickly differentiate between hands with 3 card support and 4 card support.

So, assuming that you are playing in a serious partnership, I suspect that its best to use something like the following

X = Negative double
2N = 3 card Heart support
3 = Natural + Forcing
3 = Good raise to 3
3 = Competitive raise with 4 card support

After 2N, 3m is to play and typically shows a 4 card major and a longer minor

After X, 3m is also to play, however, this could be a 5M / 4m


2NT as a 3-card raise always seemed strange to me, playing Acol.
OK when opener has five, unless 3NT happens to be a better spot.
The problem comes when opener has 15-17 balanced with 4s.
Now you have wrong-sided 3NT.

Might be better to swap 2NT & 3.
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