my system thoughts

[Flame]

This post contain some major mistakes claiming to have a thory that i now know was wrong, i explained more in respond on this thread, sorry.

This is based on this article by david_c david's article

Opening structure:

1S - 4+♠ 11-15 (could be canape)

1H - 12-18 (this one still open see thoughts at the end

1NT -12 14

1D - 12-GF- 4+ ♦ unbalanced

1C - 15+ bal or clubs ,19+ with hearts or 16+ with spades or GF with diamonds

2 level see at the end

 

david_c claimed that these different ranges for types of hands in the 1C openeing will cause problems constructing a system that works over 1C.

I think this works pretty naturaly.

1C-1D width range of weak (not transfers like in milnium)

1H - 18 bal or 19+ any hand

1S=16-19 with 5♠

1NT=15-17 bal

2C - 15-18 5+ clubs

2D - any GF like in polish

continuations over 1H relay are known from many system.

The seonnd intersting point of this structure is the 4CM 1♠ opening.

i wont get into it now, but i its based on my thory that

1. Spades are less important to distinguege between 4 and 5 cards.

2. Its good to open 1S often.

I also consider killing the precision 2C sending the good 6 cards to open 3C, and the bad 6 cards to open 1nt. This leaves me with hearts and clubs.

This could leave the 2 level for my heart toy, which is another part of that thory

to open weak unbalance hearts hands at the 2 level.

I plan to use 2C/2D to show hearts and minor around 8-12 hcp,what i didnt decide is the shape whater it should be 5/4 either way or 4+4+ or always 5m-4H or always 5H-4m.

Any thoughts are welcome.

Edited November 4, 2005 by Flame

[Flame]

Another thought i had

If i use 2m to show 4+4 or (5/4) H and m, 2H= 6H,2S=11-14 5-4 minors

I could make the 1D and 1H forcing bids like F-N system.

But this is another totally diferent system.

[david_c]

david_c claimed that these different ranges for types of hands in the 1C openeing will cause problems constructing a system that works over 1C.

I think this worls pretty naturaly.

Fair enough. I can't remember why I said that :)

[tlgoodwin]

i wont get into it now, but i its based on my thory that

1. Spades are less important to distinguege between 4 and 5 cards.

 

Flame, can you elaborate on the part of your theory about the lack of importance of distinguishing between four and five spades?

 

Jean-Rene Vernes argued just the opposite: he held that distinguishing between 4 and 5 spades should be a primary objective of a bidding system. He went so far as to devise a method (La Majeure D'Abord, 1971) in which 1S showed five (or more) spades and 1C showed exactly four spades. I've been experimenting with a method that flips Vernes' meanings, so that 1C shows five spades and 1S shows four. If you are correct about the unimportance of distinguishing between four and five spades, then I have been wasting my time with that experiment. (I don't regard that as especially unlikely, given the results of other experiments I've tried.)

 

I'd really like to hear your argument.

[Flame]

i wont get into it now, but i its based on my thory that

1. Spades are less important to distinguege between 4 and 5 cards.

 

Flame, can you elaborate on the part of your theory about the lack of importance of distinguishing between four and five spades?

 

Jean-Rene Vernes argued just the opposite: he held that distinguishing between 4 and 5 spades should be a primary objective of a bidding system. He went so far as to devise a method (La Majeure D'Abord, 1971) in which 1S showed five (or more) spades and 1C showed exactly four spades. I've been experimenting with a method that flips Vernes' meanings, so that 1C shows five spades and 1S shows four. If you are correct about the unimportance of distinguishing between four and five spades, then I have been wasting my time with that experiment. (I don't regard that as especially unlikely, given the results of other experiments I've tried.)

 

I'd really like to hear your argument.

Im sorry and also imberest to say that most of that "thory" wasnt true.

Im glad you asked me, it made me sit down and write numbers, checked many of those things that i thought about before but never accuretly calculated them, and find out that i was wrong.

What i can say is that obviously opening 4 or 5 card major has plus and minuses, now opening 1♥ with 4 cards has almost no pluses when you open 1H,while opening 4 cards spade has, in other words opening 4 card spades will give you over avarage results when you open 1S much more then opening 1H with 4 cards hearts. (notice that my claim is only about the times you do open 1M and not how it effect the rest of the system and when you open something else, and also only about when you get a better results then those who play 5 cards major, didnt say anything about the times you get worse results).

This mean i dont like the 4 cards 1H opening, also mean i might want to open 1S with 4, and also might mean i want to distiguege between 4 card spades and 5 cards spades (and not distiguege hearts since i dont want to open 4) which is exactly what those you mentioned claimed.

Sorry for my mistakes, that come from lazyness.

[hrothgar]

What i can say is that obviously opening 4 or 5 card major has plus and minuses, now opening 1♥ with 4 cards has almost no pluses when you open 1H,while opening 4 cards spade has, in other words opening 4 card spades will give you over avarage results when you open 1S much more then opening 1H with 4 cards hearts. (notice that my claim is only about the times you do open 1M and not how it effect the rest of the system and when you open something else, and also only about when you get a better results then those who play 5 cards major, didnt say anything about the times you get worse results).

This is still "just" a statement without much in the way of supporting evidence.

 

One quick comment about your proposed system:

 

I find long lists of coventions and treatments somewhat difficult to parse.

In general, when I'm evaluating system I strongly prefer to state with the "basics": What are trying to accomplish? How are you prioritizing different elements of the system design. For example, MOSCITO is based arround a number of explict design goals:

 

1. Limited openings with a high frequency

2. Get to 2M ASAP

3. Constructive openings should promise a 4+ card suit (we want to bounce the bidding ASAP, so no nebulous clubs or diamonds)

4. There is great discord under heaven and the situation is excellent (we deliberately attempt to neutralize the opponent's ability to apply the Law)

 

It might be useful if you tried to compile your own list...

[awm]

For a totally different idea, how about these priorities:

 

(1) Openings should show a 5+ card suit as often as possible.

 

(2) Shape is most important on the first bid of the auction; responder can limit his hand first.

 

(3) Maximize the number of natural, nonforcing preemptive openings.

 

(4) Relays are great when relayer has a relatively balanced game-forcing hand; however holding shape there should be the option to bid out the hand in a natural, forcing manner.

 

Here's the system structure:

 

1♣ = no five card major, no 5-card diamonds unless a balanced hand type, forcing

1♦ = 5+ hearts, 1-round force

1♥ = 5+ spades, 1-round force

1♠ = 5+ diamonds, 1-round force

1NT = 14-16 balanced

2♣ = 6+ clubs, 8-13 hcp (with 14+ open 1♣)

2♦+ = natural preempts

 

In response to 1♣, most bids are transfers. Accepting the transfer shows minimum values for the opening; other bids extras (and natural-ish). In response to 1♦/1♥, accepting the transfer shows 0-8 hcp (but not 5-8 with 3+ support or 5-8 with a decent 6+ suit). The 1NT response shows 9+ (unlimited) with 0-2 cards in the major and otherwise fairly flat (denies 6+ in a suit or 5-5 in two suits); opener's rebid will be basically natural, responder can then make the minimum call to start game forcing relays, or bid anything else to invite (opener's rebids basically unlimited, responder will not pass). 2/1 bids over 1♦/1♥ are natural and forcing, showing either: an invitational hand with 6+ in the bid suit, an invitational 5-5 with the bid suit and a lower suit, a game forcing hand with 5+ in the bid suit and 3+ support for opener, a game forcing hand with 6+ in the bid suit, or a game forcing 5-5 with the bid suit and a higher suit. Direct jump shifts to new suits over 1♦/1♥ are constructive (5-8) and natural. Jump to 2NT is either 3-card limit raise or a GF raise; jump to 3M is 4-card limit, jump to 3NT is a minimum-ish balanced game-forcing 3-card raise. Over 1♠, 1NT/2♣ show 4+♥ and 4+♠ respectively (forcing one round). 2♦ by responder shows a weak hand (0-8) with no 4-card major. 2♥/2♠ show forcing hands with clubs and diamonds respectively. 2NT is natural game force (kind of a shortness ask), 3♣/♦ are natural preempts (generally deny 4cM). Most followups fairly natural. Over 1NT/2♣ can play pretty much any methods (I prefer Keri-Garrod over 1NT and transfer responses over 2♣).

 

Anyways, curious what people think of this particular idea. I'd be playing it a lot if only it was allowed over here in the states (transfer openings not even mid-chart, so disallowed in most events).

[david_c]

That's a cute idea Adam.

 

I suppose the weak point is likely to be the 1♠ opening. Having lots of forcing opening bids decreases the total amount of space available in the system, and probably 1♠ is where you will feel this most acutely. I might be tempted to give up the 2♦ pre-empt.

 

1♣ is also not great of course. But it could be worse.

 

All in all, probably a good system against opponents who like to interfere a lot. :rolleyes:

[Robert]

Hello awm

 

Reese played the Little Major in the 60s(I think?).

1C=4+ hearts

1D=4+ spades

1H=20+HCP

1S=minors(possible 5-4 either way)

1NT=12-14(A guess here, it has been a while since I read the system outline)

 

He used the step between much like 2C-2D 'waits' as it is sometimes used in America. Accepting the transfer 1D-1S showed 3+ card support. If you jumped you had 4+ card support and normal single raise values(I think?)

 

Having that 'step' in between appears to me(I am a system nut) to be a considerable advantage.

 

I have played some strange systems('forcing' Pass and some systems with an opening 8-10HCP NT) so I do not have problems with different types of bidding systems.

 

How do you bid over that 8-13HCP range 2C opening. I define my 11-15 range(in my Big Club 2C opening mehtod) fairly well, however, the 2C opening is normally the 'weak link' of a Big Club type system.

 

I also played Roman Club and they suggest opening 3=3=2=5 hands in a 'three' card major to canape into clubs. After making jump preference bids with 'four' card support and hitting opener with 'a' three card major opening, I changed the system to 4 card majors and the 1D* bid might be shorter.

 

The ACBL is protecting both of us from 'transfer' openings. Do you happen to play Jacoby transfers over NT openings like millions of ACBL members also play?

 

Regards,

Robert

[awm]

Some more philosophy to answer some of these questions:

 

(1) I believe that a five-card suit style leaves partner better placed than a four-card suit MAFIA style. Obviously not everyone believes this, but I should note the prevalence of 5-card majors worldwide, and the fact that even Moscito has removed (in the most recent version) 4M-6m two-suiters from the major suit openings. Statistically, after a five-card major opening our best fit is in that major over 67% of the time, versus only about 50% for four-card majors.

 

(2) I'm not a big fan of artificial strong bids. These bids basically come in three flavors. There are the ones where you open at the two-level (i.e. 2♣) with very strong hands. This type takes up a lot of your own space, and happens with relative infrequency. You're basically "wasting" a bid that could be put to more frequent use, and not necessarily even reaching the best contract when it comes up. Then there are the low-level lower-threshold strong bids (big ♣ or ♦). These look nice in constructive auctions, but when the opponents butt in you will often be put to a high-level guess with little information to go on. Finally there are the "multi-way" bids like the polish ♣. These deter some of the more "crazy" preempts from opponents, but when they do interfere you are quite poorly placed as partner doesn't even know whether you have the strong hand at his first turn, much less what your distribution might be.

 

(3) The motivation for this system design is the methods and results of Fantoni and Nunes. It seems like there are big advantages to opening with natural bids on the big hands. Another example, look at all the big two-suiters posted as bidding challenges. They're tough to get right. You can sacrifice most of your natural preempts to play Misiry... or you can just open with a forcing bid showing your first suit, and subsequently bid your second. One of these styles seems superior to me, but fans of artificiality may disagree.

 

(4) Perhaps the last point is that I am not particularly in love with the weak notrump, and I like having natural two-level preempts available, and opening my one-bids at the one-level. If not for these things I would probably play Fantoni-Nunes style. So I asked myself, is it possible to get the advantages of their methods (show your suits right away on strong hands) without the perceived disadvantages (12-14 notrumps, intermediate two bids, can't open 10-12 hcp hands at one of a suit). The transfer approach seemed to me to be best of both.

 

As for the 2♣ opening, all preempts are double-edged in a way. I'm not convinced that the precision 2♣ (in a version where it always shows six) is necessarily a loser -- you lose on constructive hands where responder has less than a game force, but you often win by pushing the opponents up a level and showing your longest suit immediately. Compare this to a standard 1♣ which basically invites opponents into the auction and is difficult for partner to raise even with four card support.

 

My methods over this (and precision 2♣) these days look something like:

 

2♦ = 4+♥; if weak generally 6+♥; opener accepts the transfer unless holding four card support (super-accept) or holding self-sufficient clubs with heart shortage.

2♥ = 4+♠, similar.

2♠/2NT = both artificial club raises, the first focusing on stoppers, the second on shortage and suit quality.

3♣ = preemptive raise

3♦-3♠ = game forcing with a good six-card suit (transfer then rebid would be invitational)

 

Obviously there are more details one could write down. I've found these methods to work somewhat better than the more classical "2♦ relay" approaches, in part because they focus on stoppers and suit quality more than distribution on the majority of hands, and in part because opener has some information about responder's hand to help with evaluation.

[hrothgar]

(1) I believe that a five-card suit style leaves partner better placed than a four-card suit MAFIA style. Obviously not everyone believes this, but I should note the prevalence of 5-card majors worldwide, and the fact that even Moscito has removed (in the most recent version) 4M-6m two-suiters from the major suit openings. Statistically, after a five-card major opening our best fit is in that major over 67% of the time, versus only about 50% for four-card majors.

Very good example regarding differences in philosophy:

 

MOSCITO isn't designed to explore for the "best" fit. Instead, we emphasize identifying an "acceptable" fit ASAP.

 

The major suit raise structure promides a perfect example: We open 1M holding a four card suit. Partner is expected to raise to 2M holding virtually any xxx. Once the auction starts 1M - 2M, we have no way to try to improve the contract. For example, a 3♣ bid shows 5+ Spades and 4+ Clubs and is exploring for game.

 

We believe that the systemic gains from forcing the opponents to guess whether or not to balance outweight the losses when we play in a 4-3 fit at the two level with a 9 card fit available in a minor...

[glen]

We believe that the systemic gains from forcing the opponents to guess whether or not to balance outweight the losses when we play in a 4-3 fit at the two level with a 9 card fit available in a minor...

It must also outweight the loses from playing in a 4-3 fit at the two level when 1NT is a better contract. If one is opening on 5678 and raising on 432 the contract can be quite poor.

[hrothgar]

We believe that the systemic gains from forcing the opponents to guess whether or not to balance outweight the losses when we play in a 4-3 fit at the two level with a 9 card fit available in a minor...

It must also outweight the loses from playing in a 4-3 fit at the two level when 1NT is a better contract. If one is opening on 5678 and raising on 432 the contract can be quite poor.

Yeap... The contract can really suck.

 

Luckily, the pressure bidding style often makes it very difficult for the opponents to determine the best defensive line. Equally significant, we don't always end up declaring when the auction starts 1M - 2M. Marty Bergen used to say that he was happiest when the opponents bought the hand following one of his preempts.

[glen]

Lately I've seen a couple of cases of systems where one of the opening one bids promise 4♠, and I found that intriguing. Combining that with the thinking of this thoughts thread, might result in:

 

1♣: 15+ bal, 15+ 5+♠s, 15+ 5+♣s, 19+ 5+♥

1♦: 10/11+, 4♦s, unbal., forcing (since unlimited)

1♥: 10/11-18, 5+♥s

1♠: 10-14, 4♠s exactly & unbal., or 5♠s exactly and no singleton/void

1NT: 11/12-14 bal

2♣: 10-14, 6+♣s or 5+♣s & 4♥s

2♦: Weak two in a major - when not allowed (or if vul?) 19-20 balanced

2♥: 10-14, 5+♠s, 4+♥s

2♠: 10-14, 6+♠s or 5♠s & a minor & a singleton/void

 

Edited for this cute variation:

1♠: 10-14, 4♠s exactly. if balanced 11-14

1NT: 11/12-14 bal, not 5♥s and not exactly 4♠s but can have 5♠s exactly and no singleton/void

 

Now 1NT-P-2♣-P-?

2♦: No four card or longer major

2♥: 4♥s, not 4♠s

2♠: 5♠s

 

One can bid Stayman on shapes like 2-4-5-2.

[david_c]

(Back to awm's system.) I like the transfers over 2♣. I fact I like the 2♣ bid anyway. I'd be more interested in how you cope with the problem auctions

 

1♣ : 1♠ , ...

 

and

 

1♠ : 2♣ , ...

 

and

 

1♠ : 2♦ , ...

[Flame]

To Richard

Just a quick remark on the the 4 card major opening.Consider the game as a competition between hearts and spades only. When you open 1S with 4 cards your partner with 3 and 4 card support is in better possition then the 5 card 1S opener, you get to find the winner spot of 2S , your opponents have hard time finding their heart fit and even if they do they have to go to the 4 level.

When you open 1H with 4 cards you gain alot less, first of all the 2H spot isnt as good sicne your opponents can be well placed playing 2S, also 1H doesnt damamge thier ability to find their spade fit as was on the opposite direction.

The heart fit makes a different when you have 9 card fit, meaning you have 5 card support to partner but then you could have bid the hearts first. (and also 5 card support is way less freqent then 3 or 4 cards)

Again i didnt claim more then this.

[glen]

When you open 1H with 4 cards you gain a lot less, first of all the 2H spot isnt as good sicne your opponents can be well placed playing 2S, also 1H doesnt damamge thier ability to find their spade fit as was on the opposite direction.

Agreed. Often the system meanings of 1♥ and 1♠ are made relatively symmetric, but there are significant advantages in opening 1♠ with 4♠s that are not found in 4+♥s 1♥ openings.

[Robert]

hello David C

 

Just a couple of guesses here.

 

awm wrote that the system plays mostly transfers over the 1C bid so I guess that 1C-1S shows one or both minors. If a one suiter, partner accepts with minimum. If it shows both minors, reply with 'pass or correct' with a miniumum.

 

1S=diamonds so I would use my 1D-2C auction over 1S*-2C.

1S=diamonds-2D I presume is to play(It might be 'inverted' however, since passing 1S(showing diamonds) might be wrong, they may not be able(or want to) use inverted minors.

 

They could use 1NT as a Lebensohl like vehicle, however, that might cost them a natural meaning for 1NT.

 

The system might have some 'toys' or special replies to take up the slack. Roman Club uses the 1NT rebid after opening 1 non club-suit reply to show 5 cards in the suit that partner bids and 12-14HCP. With 5 card support and 15-16HCP you could make a single raise. 1D*-1H*-2H*

 

I would be more concerned about his 1S=diamonds-2H auction. That takes up a lot of space and may cause some real problems.

 

Maybe the Hackett reversal of 'canape' for clubs(substituting diamonds for clubs) The Hacketts bid 1M-2D-3C*=strong NT values and 1M-2D-2NT*=clubs any range. If partner signs off in 3C, your higher bids show game values opposite the 2D reply.

 

Over my suggested' problem 1S*-2H you could bid 3D* with 15+HCP balanced,

bid 3C natural and canape into diamonds(any range) with 2NT.

 

Regards,

Robert

[hrothgar]

To Richard

Just a quick remark on the the 4 card major opening.Consider the game as a competition between hearts and spades only. When you open 1S with 4 cards your partner with 3 and 4 card support is in better possition then the 5 card 1S opener, you get to find the winner spot of 2S , your opponents have hard time finding their heart fit and even if they do they have to go to the 4 level.

When you open 1H with 4 cards you gain alot less, first of all the 2H spot isnt as good sicne your opponents can be well placed playing 2S, also 1H doesnt damamge thier ability to find their spade fit as was on the opposite direction.

The heart fit makes a different when you have 9 card fit, meaning you have 5 card support to partner but then you could have bid the hearts first. (and also 5 card support is way less freqent then 3 or 4 cards)

Again i didnt claim more then this.

The MOSCITO variant that I play actually compensates for Hearts and Spades, albight in a somewhat different manner.

 

MOSCITO uses an 11+ 14 HCP 1NT opening range.

This range overlaps with that of the 1M opening.

 

I decided to reconcile this in the following manner:

 

If opener has 4-5 Spades and a balanced hand, he opens:

 

1♠ with 11+ - 12 HCP and

1N with 13-14 HCP

 

This maximizes openers ability to show the master suit.

 

If opener has 4-3 Hearts and balanced hand, he opens

 

1♥ with 13 - 14 HCP and

1N with 11+ - 12 HCP

 

This minimizes the opponents ability to show Spades at the one. It also places the partnership in a better position if we need to worry about balancing. If we show Hearts, than we promise an unbalanced hand or extra strength.

 

In short: I agree with your basic premise. However, I don't think that its necessary to adopt a 5+ card 1♥ opening.

[david_c]

awm wrote that the system plays mostly transfers over the 1C bid so I guess that 1C-1S shows one or both minors.

Well, you also have to consider balanced rubbish like

 

♠ xxx

♥ xxx

♦ xxxx

♣ xxx

 

I was assuming those would go into 1♠. In which case, what do you do over 1♠ with a balanced 17-18? You can lump those in with your "minimum" 1♣ openers, but then that reduces the number of hands you can respond 1♠ on. Alternatively you can decide to play 1♣:1NT as the default negative, but then you have similar problems there.

 

1S=diamonds so I would use my 1D-2C auction over 1S*-2C.

No, 2♣ shows 4+ spades, 0+ HCP (see awm's original post).

[Robert]

Hello David C

 

1C-1S showing a zero count 3433 is 'somewhat' dangerous. Bidding 1C-1NT is even more dangerous.

 

If I wanted to use transfers and lost my 1C-1D negative bid, I think that I would try transferring to my lowest 3-4 card major and pass openers next bid if at all possible.

 

A reverse style Polish Club type auction after 1C-1D(neg.)-1M shows 3-4 cards.

 

1C-1D*=hearts(3-4 cards with 3343 seems better than 1C-1S saying I may have zero HCPs.

 

Didn't he say that he 'accepts' the transfer with minimum values and bids higher with extras. If he accepts, you pass.

 

If he bids higher, you pass anything that is not forcing. I do not recall his 1NT range. If it is 14-16, he could bid 1C-1D*-1NT showing 17-19.

 

I will close now and go back and check his 1NT range.

 

Are we looking at the same posts. I see 1S(which I believe=diamonds)-2C

which you think shows 4Ss and 0+HCP.

 

If the 1S bid shows spades fine. If the 1S* bid shows diamonds, bidding 1S*-2C showing 4 spades(with 0+HCP) does not appear to be a playable method.

 

I am curious. I will read the first post again very carefully.

 

Regards,

Robert

[Robert]

Hello David C

 

awm first post says 14-16HCP 1NT so my idea of bidding 1C-1D* 3+ heart transfer can be followed by a 1NT bid showing 17-19.

 

Partner can use Stayman or transfers to find out about major contracts 'if' he has values. If he is weak with five plus in hearts, he can transfer or pass as their methods and style permit.

 

I will look around some more to see what the 1S-2C auction means.

 

Regards,

Robert

[Robert]

hello David C

 

As far as I can make out: 1S=diamonds and 2C* does indeed show 4 spades(he says that it is a one round force in brackets) He also lists 1S*-2D*=no major and

0-8HCP.

 

I did not read the follow up details so my mistake in not 'knowing' that 1S-2C is 4 spades. You might have misread the 2D auction showing 0-8HCP and the one round force following 1S*-2C spade showing bid.

 

Ain't science wonderful?

 

It appears to me that the auction 1S showing diamonds-1NT and 2C showing hearts and spades respectively(and a one round force) is not nearly as good a method of bidding as 1D natural-1M(a one round force) since we can bail out in 1NT in the second auction.

 

Do you pass with less than 10HCP over a 1S* opening showing diamonds?

Forcing with much less than 10HCP over a 1S* opening is very dangerous. After you bid a forcing one round 1S*-1NT or 2C you cannot bail out in 1NT if the hands do not fit. Bidding 2NT without serious values is also not recommended.

 

I also do not see how you get to a 5-3 fit in responders major after 1S*-1NT or 2C showing a 4+ major. If parnter accepts with 3, responder still does not know if he has a 4-3 or 4-4 fit.

 

Maybe the Hackett method of majors first should be tried. You could use the

Little Major method where 1C and 1D showed 4+ cards in hearts and spades.

 

Natural one suiters of 2C and 2D and an opening 1S showing at least 5-4 minors.

The Little Majors' 1H* opening showing 20+HCP could somewhat limit the other system openings.

 

Maybe awm can post so more information on his methods?

 

Regards,

Robert

[awm]

Here are responses to 1♣:

 

1♦ = 4+♥

1♥ = 4+♠

1♠ = no 4cM, if balanced will be 0-5 or 12+, if unbalanced less than GF

1NT = 6-11, i.e. enough to cope with a 2NT raise from 17-19, but no game opposite 11-13

2♣/♦ = natural and game force

3♣/♦ = single suited invite (something like 10-11, 6+ cards)

 

After 1♣-1♠:

 

1NT = balanced hand, 11-13 or 17-19; 3-suited also possible if no 5-card clubs

2♣ = 5+♣, not a lot extra

2♦ = very strong hand, balanced or (4441) type

2♥/♠ = normal reverse, 5+♣ 4cM

2NT = super-strong club hand, no side major

3♣ = a sound 3♣ call

 

After 1♣-1♠-1NT: pass with 0-5, 2m with a suit (expect partner to pass w/11-13), 2NT=12-13, major suits and 3-level used to show invitational minor two suiters.

 

After 1♠-2♦ (min no major): pass with a minimum; 2M would be a sound reverse after a standard auction like 1♦-1NT, 2NT is super-strong hand, 3♦ is NF but enough extras for game possibilities.

 

After 1♠-1NT/2♣ (showing H/S): 2♣ shows 4 spades, frequently raise with 3-card support of partner's major, 2♦ rebid natural minimum, others much like after 1♠-2♦.

 

As to "don't we lose the ability to rebid 1NT": the 1♠ opening is generally an unbalanced hand with 5+♦, with 2353 or the like normally open 1♣ or 1NT. So these aren't hands that most people will bid/rebid 1NT on anyway. The only real loss here is that it becomes difficult to show hands with 5-4 in the minors; you don't really lose major fits.

[david_c]

It appears to me that the auction 1S showing diamonds-1NT and 2C showing hearts and spades respectively(and a one round force) is not nearly as good a method of bidding as 1D natural-1M(a one round force) since we can bail out in 1NT in the second auction. 

Robert,

 

I think you are now realising why my first comment on this system was, "I suppose the weak point is likely to be the 1♠ opening. Having lots of forcing opening bids decreases the total amount of space available in the system, and probably 1♠ is where you will feel this most acutely."

 

For what it's worth, I think Adam's way of responding to 1♠ is the best available, but it still has big problems. You'll be playing a lot of 2♦ contracts on 5-1 fits. And the range for 1♠:2♣,2♦ and 1♠:2♣,2♠ is very wide so you're probably going to be missing a lot of games (or, if you prefer, stretching to silly ones). If you try to make the range narrower then you have a corresponding problem with wide-ranging reverses. And after all that you still have to sort out responder's rebid problem, at the two-level with a range of "0+" to deal with.