Response structures after a MOSCITO 1S opening

[hrothgar]

Hi All: Question for the peanut gallery

 

Right now, MOSCITO's 1♠ opening shows

 

Unbalanced hand with 4+ Diamonds

Could have longer clubs

Denies a good 4 card major

~9-14 HCP

 

At the moment, MOSCITO uses the following advance structure

 

3♦ = Value raise

3♣ = Pass or correct to 3♦

2N = Limit raise+ in support of Diamonds

2♠ = 3+ Clubs and 3+ Diamonds, game invite

2♥ = 5+ Clubs

2♦ = 5+ Spades

2♣ = 5+ Hearts

1N = Relay

 

I was considering a major change in the definition of the 2H advance. Ideally, I'd like a better mechanism by which the partnership could explore for a major suit fit at the 2 level with weak hands. Being able to identify a nice 4-3 or even 5-3 fit major suit fit would be quite nice, especially at MPs.

 

One possibility would be using 1♠ - 2♥ to show a reverse flannery hand type (5 Spades, 4 Hearts). The normally flannery hands can be bid starting with a 2♣ trasnfer to hearts and then showing Spades if partner denies heart interest.

 

The other possiblity (which has some attraction) would use 2♥ to show

 

4+ Spades

4+ Hearts

3+ cards in one minor

 

You lose out on the ability to find a known 5-2 fit, but increase the frequency of the bid and increase the chance of finding a 4-3 fit.

 

Any thoughts?

[whereagles]

Looks like you need a "matchpoint moscito" fix :) Anyway, how about:

 

1♠ 2♦ = multi style, weakish or strong. If weak 6+ cards. If strong 5+ cards.

1♠ 2♣ = 5-4 majors either way, weak/strong. Opener bids 2♦ with no preference.

[Echognome]

I can tell you what we do in Echo club. Have in mind however that there are slightly more hand types (as we do not have a precision 2♣), so 1♠ is one or both minors.

 

Then,

 

Pass 5+♠ weak

1N To play (or correct to 6+ minor, may have 5 card major)

2♣ Any invite*

2♦ 5+♥, to play or invitational

2♥ 5+♠ INV

2♠ both minors, either PRE or GF

2NT GF inquiry**

3♣/3♦/ PRE

3♥/3♠ GF Single-suited (sets the suit)

3NT To Play

 

* After 1♠ - 2♣ - ?

Pass Single-suited clubs, min

2♦ Single-suited diamonds, min

2♥ 1=3=(45) or 0=3=5=5 min

2♠ 3=1=(45) or 3=0=5=5 min

2NT 2=2=(45) or (12)=5=5 min

3X Same as above but max

 

** After 1♠ - 2NT - ?

Same as above for hand types but doesn't show min or max

 

Note also that we treat 6-4s as single-suited in first instance. Then we bid our 4 card side suit next if we have the chance. Note however that in Echo club, one cannot have a 4cM and open 1♠.

 

So we decided to give up on the full relay over 1♠ in order to be able to play in 1N, 2♣, or 2♦ on the part scores.

[awm]

Here's another alternative:

 

1NT = relay

2♣ = asking, 4-4 majors, or 4M and 4+m, or 5M (not 2♦/2♥ bids), or weak 6+♣

2♦ = 6+♥, or 5♥ with 4♦, or 5♥ with 3-3 minors, or 5-5M inv

2♥ = 6+♠, or 5♠ inv, or 5♠ with 4♦, or 5♠ with 3-3 minors

2♠ = 3+/3+ minors inv

2NT = LR+ in diams

3♣ = preemptive 4+♣ and 3+♦ (pass/correct)

3♦ = preemptive raise

 

after 1♠ - 2♣:

 

2♦ = 6+ diams, no 4cM

.... pass = was looking for 4-4/4-3 major fit, or 5M with very short diams, no 5-side suit

.... 2♥ = 5-5 majors weak, or 5♥+5♣ weak, or 5♥ and 2-3♦ weak

....... pass = doubleton heart

....... 2♠ = 2-3♠, spades longer than hearts

........... pass = 5-5 majors

........... 2N = 5♥+4♣+(2-3)♦

........... 3♣ = weak 5-5

........... 3♦ = 5♥ and 2-3♦ weak

....... 3♣ = no major interest, 4+♣

........... Pass/3♦ to play, else show weak 5-5 with clubs

....... 3♦ = likely 2173 or even 1183

....... 3♥ = 3♥ and a pretty good hand

.... 2♠ = 5♠+5♣ or 5♠ and 2-3♦, weak

....... pass = doubleton spade

....... 2N = 0-1♠, 2-3♣, prefer clubs if partner is 5215 or the like

....... 3♣ = 6♦+4♣ likely 1264

....... 3♦ = 7+♦, not real interested in alternate strains

....... 3♠ = 3♠ and a pretty good hand

.... 2N = inv likely not a great diam fit

.... 3♣ = just clubs, signoff

.... 3♦ = inv with 2-3 diams, likely 5cM

2♥ = 3♥, 4-5 or 5-5 minors; or 4♥ and 6+♦

.... pass = 4-5♥ weak

.... 2♠ = ask longer minor

.... 2N = inv, no particular fit (likely 5♠)

.... 3♣ = 4+♠ and 4+♣

.... 3♦ = 4♠ and 4+♦

.... 3♥ = 5♥ and invite

.... 4m = really good minor suit fit, not a lot wasted in spades, look for 5m

2♠ = 3♠, 4-5 or 5-5 minors; or 4♠ and 6+♦

.... pass = 4-5♠ weak

.... 2N = inv, no particular minor fit (likely 5♥)

.... 3♣ = 4+♥ and 4+♣

.... 3♦ = 4♥ and 4+♦

.... 4m = really good minor suit fit, not a lot wasted in heart, look for 5m

2N = 5+/5+ minors

.... 3m = preference

3♣ = 4♦ and 6+♣

3♦ = very strong 7+♦ suit, something like AQJxxxx and a side card

 

After 1♠ - 2♦:

 

2♥ = 0-2♥, not an amazing long suit

.... Pass = 6+♥ signoff

.... 2♠ = 5-5 majors inv

.... 2NT = inv 5♥ + 4♦ or 5♥ + 3/3 minors

....... 3♣ = longer clubs, min, pass/correct

....... 3♦ = longer diamonds, min

....... Else = game-going

.... 3♣ = weak 5♥ + 3/3 minors

.... 3♦ = weak 5♥ + 4♦

 

After 1♠ - 2♥ similar to above

[cherdano]

Is it really a good idea to try to find KNOWN 4-3 fits with a weak hand? Sounds like asking for a loud double to me... (Assuming your opps get the chance to agree that doubles vs known 4-3 fits are penalty.)

 

Arend

[hrothgar]

Is it really a good idea to try to find KNOWN 4-3 fits with a weak hand? Sounds like asking for a loud double to me... (Assuming your opps get the chance to agree that doubles vs known 4-3 fits are penalty.)

 

Arend

The formulation that I suggested would use 2♥ to show 4+ cards in both majors. 5-3 fits would still be possible. Hell, a 5-4 fit is theoretically possible...

[hrothgar]

I spent some time running simulations testing the 2♥ response.

 

The first thing that I discovered is that conditional probability is a royal pain in the butt. In a none-too-surprising development, it turns out that if responder holds 4+ Hearts and 4+ Spades, it makes it much less likely that opener has 3+ Hearts or 3+ Spades. In fact, it turns out that if responder holds a hand suitable for this 2♥ advance, opener' with be sitting on (0-2) Hearts and (0-2) Spades a whooping 50% of the time. I think that the idea still has some merit, however, I think that it becomes a lot more important to define some good scrambling mechanism.

 

I considered a couple potential changes including turning the bid into a true flannery type response that would unambiguously promise 5+ cards is a specified major. This was better on a purely constructive basis - the partner was well positioned to identify 5-2 fits - however, the frequency was abysmal. A more promising option was to require that responder hold 2+ Diamonds. This helps in a couple ways. The partnership can immediately identify both 4-3 major suit fits, as well as 6-2 diamond fits. It also improves the subsequent scrambling auctions.