1D (2H)

[straube]

Looking for help with 2H interference of our nebulous 1D (10-15, no 5M, no 6m unless 5m/6m). Is this good? Can we do better?

 

1D (2H)

 

dbl-negative or NFB spades

.....2S-2 to 4 spades

..........P-NFB

..........2N-GI 4 spades

..........cue-GF stopper ask

..........other-natural, GI 4 spades

.....3S-4 spades, max

2S-GI+, spades

2N-asks better minor (competitive both minors or GI+ diamonds)

.....3C-clubs

..........3D-to play

.....3D-diamonds, weak

.....other-natural and diamonds, max

3C-GI

3D-GF clubs

3H-stopper ask

3S-weak

[rbforster]

What do you do with a balanced invite, say a hand that wants a natural 2N call? Seems like that one gets lost trying to cater to the weak long spades hands. Given they're already showing weakness and your opener is limited, it seems like you might not want to prioritize weak hands by responder.

[straube]

Thanks for your feedback. I'll try to defend it but I'd be interested to know if you agree with my reasoning or if you think the invitational 2N is just too important.

 

We used to play 2S as a negative free bid and we used to play Transfer Lebensohl with similar reasoning that others play 1N (2S) 2N as some form of Lebensohl. Very often

opener has an 11-13 balanced hand and the idea is to assume that and decide (with that balanced invite) whether to go high or low. 2N is kind of an inglorious contract

and compared to other folks who open a natural minor and face 2H, we might be in 2N when those folks are in 3m.

 

After 1D (2H) 2N we would really have little use for the 3-level. Unless opener has 5/5 in the majors that is. I suppose opener could rebid 3D to play with 4153 or something but we've no guarantee of a diamond fit. So other than 3N, a natural 2N is kind of a dead end.

 

The other thing is this would get us invitational as well as forcing ways of bidding minors as well as being able to competitively handle all 5/5 hands. With 5S/5m dbl and play 2S if offered or correct to diamonds if opener is short spades. Might even handle 5S/4m as opener will have at least 3-cd support for that minor and usually 4-cd support.

 

Probably the last thing is just a frequency issue. 2N invitational with no 4 spades and no 6-cd minor and heart stopper but not wanting to trap....

 

If you think we need 2N invitational, any suggestions for the rest of the structure?

[rbforster]

Can you clarify what your 1D opener is? I guess it's often 11-13 balanced, but then can be many unbalanced hands without 5M or 6m.

[straube]

Sure. 11-13 bal, 5+m/5+m, 5m431,5m440, 4441. We open 6m/4 with 2m

 

I feel like too much is invested in spades. If double handled spades (or maybe dbl and 3H for 6S) and 2S denied spades we might rightside more contracts.

[Kungsgeten]

What would happen if we make the NFB a tad stronger? I'm thinking that the NFB shows constuctive to invitational values.

 

1D--(2H)--dbl--(pass);

2S = Would have passed the NFB

2NT = 3 spades, extras + heart stopper

3m = Short spades?

3H = 3 spades, extras, no heart stopper

 

Now I think we could manage if 2NT is GF with 5+ spades, thus leaving 2S and 3m. Perhaps the extra bidding space of 2S can be of some use?

[straube]

Yeah, probably stronger.

 

I looked at hands and slightly less than half of responder's hands had 4 or more spades which makes me wonder if assigning both dbl and 2S to spade hands makes sense. Maybe it does though.

[foobar]

Here's some data from a dealer script (scroll to the end) that might help you. The total number of hands produced were ~96,000, and since it's pretty close to 1,00,000, you can add the frequency data to get an approximate % of relative frequencies.

 

For example, the 1D opener (south) will hold frequently hold 3-4 ♠, but responder holds exactly 5♠ < 20% of the time.

 

South spades: 3.16151

North spades: 3.78056

Frequency south spades:

0 249

1 3644

2 16655

3 35228

4 40189

Frequency north spades:

0 310

1 3062

2 12484

3 24922

4 27643

5 18195

6 7283

7 1802

8 231

High 33

South clubs: 3.68685

North clubs: 3.52671

Frequency south clubs:

0 78

1 1810

2 10746

3 26452

4 33244

5 23635

Frequency north clubs:

0 569

1 4764

2 15748

3 27060

4 26119

5 15126

6 5319

7 1110

8 139

High 11

South diamonds: 3.68518

North diamonds: 3.53636

Frequency South diamonds:

0 98

1 1864

2 10673

3 26521

4 33170

5 23639

Frequency north diamonds:

0 594

1 4750

2 15678

3 26725

4 26215

5 15250

6 5471

7 1114

8 160

High 8

Generated 10000000 hands

Produced 95965 hands

Initial random seed 1455572041

Time needed 14.00 sec

 

Dealer script follows:

 

#Some convenient definitions for our openings

#This doesn't need changing

 

LimitedOpening = hcp(south) >=10 && hcp(south) <= 15

NoFiveCardMajor=spades(south) < 5 && hearts(south) < 5

BalancedHand=shape(south, any 4432+any 5332+ any 4333)

WeakNTNoMajor=hcp(south) >= 11 && hcp(south) <= 13 && BalancedHand && NoFiveCardMajor

1DUnbalanced=LimitedOpening && !BalancedHand && NoFiveCardMajor && diamonds(south) < 6 && clubs(south) < 6

 

#Actual definitions for our openings

#This doesn't need changing

 

TwoDiamondOpening=LimitedOpening && NoFiveCardMajor && diamonds(south) >= 6

TwoClubOpening=LimitedOpening && NoFiveCardMajor && clubs(south) >= 6 && !TwoDiamondOpening

FirstNTOpening=hcp(south) >= 14 && hcp(south) <= 16 && BalancedHand

ThirdNTOpening=hcp(south) >= 15 && hcp(south) <= 17 && BalancedHand

OneSpadeOpening=LimitedOpening && spades(south) >= 5

OneHeartOpening=LimitedOpening && hearts(south) >= 5

OneDiamondOpening=WeakNTNoMajor || 1DUnbalanced

StrongClub=hcp(south) >= 16 && !FirstNTOpening

 

#Some definitions to allow biasing of overcalls

#This can be changed by addding additional entries

 

HeartsWest=hcp(west) >= 8 && hearts(west) >= 5 && spades(west) < 5

SpadesWest=hcp(west) >= 8 && spades(west) >= 5 && hearts(west) <=4

ClubsWest=hcp(west) >= 10 && clubs(west) >= 6

DiamondsWest=hcp(west) >= 10 && diamonds(west) >= 6

HeartsEast=hcp(east) >= 8 && hearts(east) >= 5 && spades(east) < 5

SpadesEast=hcp(east) >= 8 && spades(east) >= 5 && hearts(east) <=4

ClubsEast=hcp(east) >= 10 && clubs(east) >= 6

DiamondsEast=hcp(east) >= 10 && diamonds(east) >= 6

 

WeakHeartsWest=hcp(west) >= 6 && hcp(west) <= 10 && hearts(west) >= 6 && spades(west) < 5

 

#Change condition to control the hands that are generated

#Examples:

#Strong club hands: condition StrongClub

#Strong club hands with LHO interference: condition StrongClub && (SpadesWest || HeartsWest || ClubsWest || DiamondsWest)

#Strong club hands with LHO OR RHO interference: condition StrongClub && ((SpadesWest || HeartsWest || ClubsWest || DiamondsWest) || (SpadesEast || HeartsEast || DiamondsEast || ClubsEast))

 

condition OneDiamondOpening && WeakHeartsWest && hcp(north) >= 8 && spades(south) < 5 && hearts(south) < 5 && clubs(south) < 6 && diamonds(south) < 6

produce 100000

dealer south

action

average "South spades" spades(south), average "North spades" spades(north),

frequency "south spades" (spades(south), 0, 4), frequency "north spades" (spades(north), 0, 8),

average "South clubs" clubs(south), average "North clubs" clubs(north),

frequency "south clubs" (clubs(south), 0, 5), frequency "north clubs" (clubs(north), 0, 8),

average "South diamonds" diamonds(south), average "North diamonds" diamonds(north),

frequency "South diamonds" (diamonds(south), 0, 5), frequency "north diamonds" (diamonds(north), 0, 8)

[straube]

1D (2H)

 

dbl-5 spades GI OR 4 spades OR like a natural 2N invitational

.....2S-minimum, 4 spades or 3 spades if no stopper

..........P-minimum, 4+ spades

..........2N-invitational, not 4 spades

..........3m-4S/5m

..........3H-asks stop

.....2N-minimum, stopper

.....3C-minimum, could be 5D/4C

.....3D-minimum, strong diamond preference

.....3H-asks for stopper

.....3S-maximum, fit

.....3N-maximum, stopper

 

2S-5 spades, forcing

2N-competitive minors or GI+ diamonds

3C-GI

3D-GF clubs

3H-6 spades, GI+

3S-stopper ask?

3N-to play

 

Occasionally this leads to playing 4-3 spade fits when 2N might be better. You'd also have to know how to handle an advance of 3H.

[awm]

After 1d-(2h)-X it seems like the 2s rebid should show four. Some reasons:

 

1. Responder is significantly more likely to have four spades than five (as per foobar's stats, plus the four spade hands include GF ones).

2. What is responder to do with 4S and inv values after the 2s rebid? 2nt misses a possible fit, 3s commits to a 3-level moysian much of the time, and other actions effectively force game.

[straube]

After 1d-(2h)-X it seems like the 2s rebid should show four. Some reasons:

 

1. Responder is significantly more likely to have four spades than five (as per foobar's stats, plus the four spade hands include GF ones).

2. What is responder to do with 4S and inv values after the 2s rebid? 2nt misses a possible fit, 3s commits to a 3-level moysian much of the time, and other actions effectively force game.

 

I'd considered that, along with dbl showing 5 spades....but dbl showing 5 spades seems wrong, too, on a frequency basis. If 2S promised 4 GI, do you have anything in mind for the rest of the structure? Maybe dbl should be invitational other....or even GF other.

[foobar]

I'd considered that, along with dbl showing 5 spades....but dbl showing 5 spades seems wrong, too, on a frequency basis. If 2S promised 4 GI, do you have anything in mind for the rest of the structure? Maybe dbl should be invitational other....or even GF other.

 

Based on the data, there are couple of reasonable approaches:

 

X: 4+ spades

.....2S: 4♠

2♠: 5+ ♠

2N: Natural, invite (stopper may be nebulous in a pinch, and opener may express doubt by bidding 3♥)

3m: Natural, forcing

 

 

X: 4+ spades

.....2S: 4♠

2♠: Ostensibly minors, maybe a signoff in diamonds?

.....2N: Denies 4cm

.....3m: Preference

2N: Natural, invite

3m: Natural, forcing

[straube]

I'd totally misread Adam's post. I had been thinking about 1D (2H) 2S forcing with four spades and dbl promising 5 spades.