Perko's Unbalanced Diamond System

[perko90]

Well, I've studied 2/1, Precision, Polish Club, Blue Team Club, and some even rarer systems in the search of my ideal system. I wanted to make the best system I could with 5-card Majors, Weak NT, and a Strong Club. But I couldn't find it. And then I read Miles' book on his Unbalanced Diamond System. While I wasn't fond of the entire system, it gave me inspiration for the missing piece to the system I was crafting . Here it is:

 

1♣ = 18+ Any dist. OR 15-17 Bal OR 15-17 4(5)+ C's Unbal (the only distro w/ 15-17 and only 4 C's is 4-4-1-4)

1♦ = 11-14 Artificial Unbal (<5M & <6 C's) OR 15-17 4(5)+ D's Unbal (the only distro w/ 15-17 and only 4 D's are (4441))

1M = 11-17 5+ M

1NT = 12-14 Bal (1st and 2nd seat), 14-16 Bal (3rd and 4th seat)

2m = 10-14 6+ m (2♦ will only have 4CM w/ strong D's and weak 4CM)

2M = weak 2's

2NT = 20-bad 22

 

I will outline some of the bidding structure for 1♣ and 1♦. The other bids can follow established treatments.

 

1♦-1M:

1♠ (over 1♥) = 11-17, 4 S's, 0-3 H's

1NT = 11-14 Unbal, 0-2 M (the only time this won't have a 5-card m is 1-4-4-4 hand after a 1♠ response)

-- 2♣ = pass or correct

-- 2♦ = artificial NMF

2m = 11-14, 5 m + 3 pc raise

2M = 4 pc raise

2♥ (over 1♠) = reverse, could have 3 pc raise, strong but NF

2NT = 15-17, 5+ D's w/ 3 pc raise

3♣ = 15-17, 5+ D's and 4+ C's, 0-2 M

3♦ = 15-17, 6+ D's, 0-2 M

3M = 4 pc invitational raise

Pass (only if ptr is a passed hand) = 10-13 and usually exactly 3 of M

 

1♦-1NT: (6-12 semi-forcing, no 4CM)

Pass = 11-13, any (4441) (w/ a singleton M, auction not likely to die w/ opp's having 9+ card M fit)

2m = 11-14 5+ m (14-15 4441 should fake a 5-card minor)

2M = 16-17, classic reverse OR (14)44, strong but NF (although almost never passed)

2NT = 16-17 4-4-4-1

3♣ = 15-17, 5+ D's & 4+ C's

3♦ = 15-17, 6+ D's

 

1♦-2♣: 13+ natural (3+ C's) GF (4CM possible w/ strong 5+ C's)

responses are natural, 2♦ shows 5+ and can still have a 4CM

 

1♦-2♦: 6-10 5+ D's, no 4CM

2M = misfit

3♦ = preemptive

 

1♦-2M: 13+ GF, 5+ D's, no 4CM, stopper showing

 

1♦-2NT: reserved for feedback

 

1♦-3♣: 6-10 usually 4-4 in minors (but cheating w/ only 3 C's can be a good gamble NV)

 

1♦-3♦: 11-12, 6+ D's (2 of top 3)

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 

1♣-1♦: 0-5(6) or strong

1♥ = 15+ w/ exactly 4 H's and unbal (canape' or 4441) OR 5 H's "balanced" (includes 18-19 where suit isn't good enough for an immediate 2♥ bid) OR 25+ bal (w/ or w/o H's)

-- 1♠ = 0-6, waiting, 2+ S's, denies 4 H's (unless total bust)

*** 1NT = 15-19 bal w/ 4-5 H's (includes some 18-19 w/ a stiff and rebid problems: 4441 and 5431)

*** 2m = canape' (4 H's & 5+ m) (if C's, it's 15+; if D's it's 18+)

*** Pass = 15-16, 4 H's & 5 S's

*** 2♠ = 17+, 4 H's & 5+ S's

*** 2NT = 25-26 bal

-- 1NT = 10+ bal, may have 4 H's

-- 2m = 0-6, 5+ m, 0-3 H's & 0-1 S's

-- 2♥ = 3-5 HCPs, 4 H's

-- 3♥ = 4-6 HCPs, 4 H's & nice distribution

1♠ = 15-19, exactly 4 S's unbal (canape') or 5 S's "balanced" (includes 18-19 where suit isn't good enough for an immediate 2♠ bid) , NF

1NT = 15-19 bal, denies 4 H's

2♣ = 15-18 6+ C's, NF

2♦-3♣ = 18+ 5(6)+ strong suit, no side 4CM

2NT = 22+ -24 bal

 

Other responses to 1♣ follow closely w/ Adam's Precision responses:

 

1♥ = 7(6)+, 4+ S's

1♠ = 7-9 bal (may have 4 H's) or 7+ & 5+ D's

1NT = 6+ & 5+ H's

2♣ = 7(6)+ & 5+ C's

 

I may outline more detail to opener's rebids and beyond a little later, but the concept is to show the 15-17 bal hand as soon as possible (usually w/ a 1NT rebid (or completing a Jacoby-ish xfr with 2♥ over 1NT) and keeping the bidding low for the unbal 15-17 club hands (2♣ most commonly, but also 1♥ and 1♠ w/ a 4CM). The 18-19 balanced, after a constructive response, most often rebids 2NT (whether a jump or not)

[straube]

A few advantages I noticed...

 

1) opener gets to show the minors while being able to rebid/play 1N.

2) the fit raises (e.g. 1D-1M, 2m) give responder a nice choice

3) solving the BW death hand

 

Not really wild about 3C rebids to show 15-17 and 5D/4C but you ought to make something most of the time.

 

More concerned about the NT ranges. I'd like to be able to open 1N with 11s (at least NV) and I'd like not to have to open 2N with

a strong hand and to show a 3-pt range. So you're like 1N=12-14, 1C and rebid 1N=15-19. This latter is pretty wide, but I guess you've

solved that a bit by using IMPrecision-like responses such that responder will be too weak or too strong to care.

 

Still, in competition, it's nice to have a stronger club and I like to get the 14-16 out of the way by opening 1N with it.

 

Not wild about the 1C-1D rebid structure. If 1H is natural, shouldn't a 1S rebid show spades? Also I get that you are opening 5-cd majors with

up to 17 or so with 1M but 1C-1D, 1M would (I think) have to include some better hands with 5+M with poor suits. Maybe you can explain more about

this.

 

Thanks for posting your system.

[foobar]

 

1♣ = 18+ Any dist. OR 15-17 Bal OR 15-17 4(5)+ C's Unbal (the only distro w/ 15-17 and only 4 C's is 4-4-1-4)

1♦ = 11-14 Artificial Unbal (<5M & <6 C's) OR 15-17 4(5)+ D's Unbal (the only distro w/ 15-17 and only 4 D's are (4441))

1M = 11-17 5+ M

1NT = 12-14 Bal (1st and 2nd seat), 14-16 Bal (3rd and 4th seat)

2m = 10-14 6+ m (2♦ will only have 4CM w/ strong D's and weak 4CM)

2M = weak 2's

2NT = 20-22-

 

Seems interesting -- here are some suggestions:

 

1) Change the 2N range to 19-20

2) Change the 1N range (1st and 2nd) to 11+ - 14

3) Consider reducing upper limit on some of the limited openings (and potentially open lighter). My personal preference would be a 9-15 range

 

Now, 1♣ is 15+ (16+ unbal) and you can use Kokish 2♥ to show the NT ranges over 1♣ - 1♦ (direct 2N is 21-23-; otherwise say 23-26 via the relay).

[benlessard]

I think opening 1D with a bal 11 is EV-, if your 1D range was 11-15 then responder could psych a response more often, but since its 11-17 the psych isnt cost free.

 

Even if 11 bal is not costing imps its not a bread and butter bid.

 

2NT = 20-22 Why ?

you feel after 1C-1D you dont have enough space to show this hand ?

After 1C-positive those strong balanced hand are never a problem and also rare.

 

After 1C-1D-??

 

you simply dont need 1H to show 4 hearts if the bid is forcing.

[Free]

When designing a system, you need to have some clear design goals. MOSCITO is a perfect example: the system definitely isn't perfect, but it fits it's design goals, which makes it a very solid system for people agreeing with these goals. So what are your design goals for the system? And how does your system fit these goals? At first glance, the system looks like some bits and pieces from other systems thrown together.

 

Some things I like about this system (like 1♦-1M-2m), some things I don't. There are many issues when opps are silent, and I think there will be even more when opps intervene.

[perko90]

Thank you all for the constructive feedback so far. Let me respond to a few of the Q's.

 

Not really wild about 3C rebids to show 15-17 and 5D/4C

Me neither! This is definitely a lesser of evils choice. I used to have the 3♣ rebid promise 5/5 shape, but I couldn't find a good home for the 5-4 D's/C's hands that were in the 15-17 range.

 

Q: Can 1NT have a lower limit (11), especially NV?

A: This becomes more of a case of personal preference rather than a foundation of the system. I tend to liberally "upgrade" 11 counts when NV v NV myself. One of the strengths I've found for weak NT is that it tends to collect a ton of profitable penalty doubles (more so at MPs), for which it's important to not "water down" the range too much. But there's room to make tweaks to the range to suit partnership preferences.

 

Q: Why 2NT 20-bad 22?

A: This is more of a "if it ain't broke, don't fix it" choice and should be thought of as a 2.5 pt range. But in general, I wanted to relieve some pressure on the 1♣ structure, which already has to accommodate a wider range of strong balanced hands than most big club systems. And the other reason is that I've never been crazy about the alternate artificial uses of a 2NT opening. But if so desired, I'm sure a partnership could tweak the rebid structures to fit that range into the 1♣ structure.

 

 

So you're like ... 1C and rebid 1N=15-19. This latter is pretty wide, but I guess you've

solved that a bit by using IMPrecision-like responses such that responder will be too weak or too strong to care.

Exactly! For all other rebids besides 1♣-1♦, the system clearly differentiates between 15-17 and 18-19.

 

Not wild about the 1C-1D rebid structure. If 1H is natural, shouldn't a 1S rebid show spades? Also I get that you are opening 5-cd majors with

up to 17 or so with 1M but 1C-1D, 1M would (I think) have to include some better hands with 5+M with poor suits. Maybe you can explain more about

this.

I'll expand my opening post on this part another day when I have more time.

 

Q: Why is the 1♥ rebid natural?

A: This is more personal preference. Even still, I didn't mention it in my OP, but I do include the 25-26 bal hands as an exception to being strictly natural

[perko90]

When designing a system, you need to have some clear design goals. MOSCITO is a perfect example: the system definitely isn't perfect, but it fits it's design goals, which makes it a very solid system for people agreeing with these goals. So what are your design goals for the system? And how does your system fit these goals? At first glance, the system looks like some bits and pieces from other systems thrown together.

Great Q! So, it starts with designing a system around 5-card majors, weak NT, and a strong club. The pros and cons of 5 vs 4 card majors, weak vs strong NT, and strong vs mixed forcing 1♣ have been debated extensively elsewhere, and I won't retread that ground. There's compelling points on either side of each choice, but I've settled on which seem best. Within this framework, I've attempted to have an emphasis on somewhat natural, constructive bidding. There's a medium amount of aggressiveness (weak NT, 2m openings), but certainly doesn't go nearly as far as some (no 4CM, no super light openings, etc.). But the biggest goal is avoiding as many awkward sequences as possible. To that end, here's some of the flaws in other systems that I've tried to improve:

 

Std | 2/1:

wide range on 1-level openings causes many problems, including:

- needing false preferences, gadgets (e.g. Gazilli) and such to sort out 2m rebids after opening 1M

- sloppy jump shifts (space-consuming, sometimes on 3-card suits, etc.)

- clumsy reverses (more often than not, the hands are somewhat of a misfit)

- chance to go 1m-all pass with the 18-19 balanced hands

- BW Death Hand

- awkward rebids with some unbalanced hands. 1-4-4-4 is a classic headache after 1♦-1♠, but there's plenty more. For ex. x AQxx Axx Qxxxx. 1♣-1♠ and now what?

 

Polish Club

- 2♣ w/ the 5 C's and 4CM shape can be awkward

- 1♦ opening and 2♣ rebid with 5-4 either way (maybe I get more than my share of 2-2 minor hands as responder, but I hate this treatment)

- awkward handling of the 12-14 bal hands after 1♣-1♦ when not having a 4CM

- sometimes it takes a long time to sort out strong hands by opener: 1♣-1M; 2♦ and such

 

Precision:

- nebulous 1♦: no matter how you slice it, it's a weakness. Hard to raise in competition vs it's natural counterpart and doesn't have any of the rebid advantages that my artificial unbalanced 1♦ enjoys

- assuming 2♣ promises 6, the 2♦ opening can be awkward and land in some sub-optimal partials (4-3 major fits and such)

 

Blue Team Club: (I have a lot of admiration for the principles of canapé)

- 5-4 either way uncertainty of a 2m rebid after a 1M opening

- wide range 1NT