Polish/Dutch Club?
#21
Posted 2023-January-06, 08:47
#22
Posted 2023-January-06, 09:56
DavidKok, on 2023-January-06, 08:47, said:
From Note 16 it looks like 1♣-1R; 2♣ is 11-16.
DavidKok, on 2023-January-06, 08:47, said:
Using 2♣ as Mexican was my suggestion, since I knew you don't like a strong balanced option in 1♦ like they had. They were able to stop in 1N after
1♦*-1M**;
1N***-P.
* NAT unBAL or 18-19 BAL
** (3?)4+ OM
*** 18-19 BAL (and 2-3 OM?)
and also use 2♣ as an Ekren-like opening.
DavidKok, on 2023-January-06, 08:47, said:
Are you talking about the sequence 1♣-1x; 2♦?
#23
Posted 2023-January-06, 10:17
nullve, on 2023-January-06, 09:56, said:
nullve, on 2023-January-06, 09:56, said:
1♦*-1M**;
1N***-P.
* NAT unBAL or 18-19 BAL
** (3?)4+ OM
*** 18-19 BAL (and 2-3 OM?)
nullve, on 2023-January-06, 09:56, said:
#24
Posted 2023-January-07, 06:10
DavidKok, on 2023-January-06, 10:17, said:
The notes doesn't say anything about the sequence 1♣-1♦; 1♠, but if the 1♠ rebid were some kind of Gazzilli there would probably have been a note about it.
Yes, there seems to be a (big) hole in the system if the notes are accurate. However, I had a look at their 2002 Bermuda Bowl system
CC
notes to CC
where, according to a new Note 16,
Quote
2H is obbliged ---> 2S = 5+C 4+D 16+
3C = 16-18 6+c
3D = asking for aces
3H = two suiter lower
3S = two suiter midium
3NT = two suiter higer
Then I went back to Note 16 to the 2001 card and saw this:
Quote
2H is obbliged ---> 2NT = 23+HCP Bal.
3D = two suiter same colour
3H = two suiter same range
3S = two suiter different colour and range longer lower
3NT = two suiter different colour and range longer higher
It's hard to believe that they intentionally left 2♠ undefined, so maybe a more accurate note would have read
Quote
2H is obbliged ---> 2S = 5+C 4+D 16+
3C = asking for aces
3D = two suiter same colour
3H = two suiter same range
3S = two suiter different colour and range longer lower
3NT = two suiter different colour and range longer higher
or something like that.
To answer your question: Assuming the way they bid hands in the ~17-22 range was something like
1♣-1x; 2♦-2♥; 2♠: with 5+C4+D
1♣-[1M-1]; 2OM: with 5+C4+OM
1♣-1♠; 2M: with 5+C4+M
1♣-1x; 2N: with a C 1-suiter in the ~20-22 range OR (x=M only) some kind of strong raise
1♣-1x; 3♣: with a C 1-suiter in the ~17-19 range
I think they would have done well to use 2N by both players as an INV+ relay (instead of, say, lebensohl) over the reverses.
E.g.:
1♣-1♥; 2♥-?:
P: allowed (remember, Responder could have nothing)
2♠ = 5+ S, NF
...P: ~17-19, 2 S
...2N = usually ~20-22, F1
......3♣ = sign off
.........P = ~20-22, 2-S4H
.........(...)
.........3♥ = 5 H, stronger than if bid directly over 2♠
.........3♠ = ~20-22, 3 S
.........(...)
......3♦+ = NAT (and mostly) GF
...3♣ = ~ 17-19, no tolerance for S
...(...)
...3♥ = 5+ H, NF
...3♠ = ~17-19, 3 S
...(...)
2N = INV+ relay
...3♣ = ~17-19
......P = was INV only, C tolerance
......3♦ = GF relay
......(...)
...3♦+ = ~20-22, NAT
3♣ = 4 S, to play
(...)
* or anyone playing a simple T-Walsh system where 1♣ contains all strong balanced hands in a certain range, so that Responder has to respond on virtually anything
#25
Posted 2023-January-08, 03:14
It's interesting that they manage to fit clubs-diamonds reverses and 16-18 with long clubs in there. I am still unclear on the ladder for hands with long clubs though. Is it something like:
- (10)11-15 open 1♣ rebid 2♣
- 16-17 open 1♣ rebid 2♦ then over the forced 2♥ bid 3♣
- 18-20(21) open 1♣ rebid 3♣
- (21)22+ open 1♣ rebid 2♦ then over the forced 2♥ pick your poison
nullve, on 2023-January-07, 06:10, said:
1♣-1x; 2♦-2♥; 2♠: with 5+C4+D
1♣-[1M-1]; 2OM: with 5+C4+OM
1♣-1♠; 2M: with 5+C4+M
1♣-1x; 2N: with a C 1-suiter in the ~20-22 range OR (x=M only) some kind of strong raise
1♣-1x; 3♣: with a C 1-suiter in the ~17-19 range
* or anyone playing a simple T-Walsh system where 1♣ contains all strong balanced hands in a certain range, so that Responder has to respond on virtually anything
nullve, on 2023-January-07, 06:10, said:
E.g.:
1♣-1♥; 2♥-?:
P: allowed (remember, Responder could have nothing)
2♠ = 5+ S, NF
...P: ~17-19, 2 S
...2N = usually ~20-22, F1
......3♣ = sign off
.........P = ~20-22, 2-S4H
.........(...)
.........3♥ = 5 H, stronger than if bid directly over 2♠
.........3♠ = ~20-22, 3 S
.........(...)
......3♦+ = NAT (and mostly) GF
...3♣ = ~ 17-19, no tolerance for S
...(...)
...3♥ = 5+ H, NF
...3♠ = ~17-19, 3 S
...(...)
2N = INV+ relay
...3♣ = ~17-19
......P = was INV only, C tolerance
......3♦ = GF relay
......(...)
...3♦+ = ~20-22, NAT
3♣ = 4 S, to play
(...)
#26
Posted 2023-January-08, 08:26
DavidKok, on 2023-January-08, 03:14, said:
I have to admit I'm not a big fan of the structure, either. They wasted an enormous amount of useful bidding space with their style of accepting transfer responses to 1♣. Just imagine what they could have done by accepting also on inverted NT hands with 2-3 M, as in the Swedish style of T-Walsh! That would free up the 1N rebid, for starters, and you could even play
1♣-[1M-1]; ?:
(...)
1N = "clubs"
2♣ = Odwrotka-like
...2♦ = 0-7, any
...2♥+: as over Odwrotka 2♦ in your system
(...)
.
DavidKok, on 2023-January-08, 03:14, said:
- (10)11-15 open 1♣ rebid 2♣
- 16-17 open 1♣ rebid 2♦ then over the forced 2♥ bid 3♣
- 18-20(21) open 1♣ rebid 3♣
- (21)22+ open 1♣ rebid 2♦ then over the forced 2♥ pick your poison
In the 2002 version the ladder was probably something like this:
11-15: 1♣-1x; 2♣
16-18: 1♣-1x; 2♦-2♥; 3♣
19-21: 1♣-1x; 3♣
22+: 1♣-1x; 2♦-2♥; 3♦(ace ask)
I don't think they took any risk on the 16-21 hands that modern standard bidders don't already take, and they seem to have been better placed on the 19-21 opposite a misfitting nothing hands.
DavidKok, on 2023-January-08, 03:14, said:
Do you really need 1♣-1M; 3♦ as ~16-20, 5+C4D3M? I think I saw a top player (Zia?) on Vugraph using this sequence for the GF one-suiter recently. Seems like a much better use of the bid than Mini-Splinter!
DavidKok, on 2023-January-08, 03:14, said:
I don't think the number of rebids (P(!),2♠,3♣(+?)) used on weak hands have necessarily changed compared to standard (P(?),2♠,2N). Well, there are many posters on BBF who think a reverse should be forcing in standard even if all Responder wanted was to escape from 1♣ (say, with xxxxx-xxx-Qxxx-x), but I'm certainly not one of them.
DavidKok, on 2023-January-08, 03:14, said:
I'm not sure I understand. I believe hands the GF hands that would rebid 2♦ are precisely the hands that would open a GF 2♦ in more recent versions of their system and that the reverses are limited by this and probably have a range very similar to reverses in standard systems.
Standard methods over reverses pretty much assume that Responder has positive values for his response. For example, if Responder could go through a lebensohl-like 2N to signal weakness with nothing (as opposed to ~5-6 hcp), Opener would not know when to bid on with a maximum. The INV+ relay is meant to solve this problem, although some might still find the ranges ~17-19 and ~20-22 uncomfortably wide.
#27
Posted 2023-January-08, 10:03
nullve, on 2023-January-08, 08:26, said:
nullve, on 2023-January-08, 08:26, said:
nullve, on 2023-January-08, 08:26, said:
I don't mind passing a reverse (or giving weak preference to opener's lower ranked suit). Opener is limited to a 21-count or so, and if responder judges that there's nothing more to look for then by all means call it quits. But it's another thing entirely to then dedicate multiple bids to finding the optimal partscore. It's relatively low gain (in IMPs) and low frequency, and does not deserve lots of bidding space.
nullve, on 2023-January-08, 08:26, said:
Standard methods over reverses pretty much assume that Responder has positive values for his response. For example, if Responder could go through a lebensohl-like 2N to signal weakness with nothing (as opposed to ~5-6 hcp), Opener would not know when to bid on with a maximum. The INV+ relay is meant to solve this problem, although some might still find the ranges ~17-19 and ~20-22 uncomfortably wide.
3-point ranges are good enough. I just worry that we won't be able to set trumps and establish a game force at a comfortably low level if all decently-strong responders have to bid 2NT. What are the responses to this bid, and where does slam investigation begin?
#28
Posted 2023-January-08, 16:52
DavidKok, on 2023-January-08, 10:03, said:
[...]
3-point ranges are good enough. I just worry that we won't be able to set trumps and establish a game force at a comfortably low level if all decently-strong responders have to bid 2NT. What are the responses to this bid, and where does slam investigation begin?
I think the biggest problem with the structure
is that Opener has no way of showing a sixth club naturally below 3N. But it's not that easy in standard, either. For example, even if 3♣ shows 6+ C over 1♣-1♠; 2♥-2♠, if it's F1 (NF), then Opener cannot bid this way with a minimum (maximum) reverse.
So here's a more artificial structure:
1♣-1♥; 2♥-?:
P: allowed (remember, Responder could have nothing)
2♠ = 5+ S, NF
...P = MIN, 2 S
...2N = MAX, 4 H, F1
......3♣ = sign off
.........P = 2-S4H
.........(...)
.........3♠ = 3 S
.........(...)
......3♦ = GF relay
.........3♥ = 6+C4H
.........3♠ = 3 S
.........3N = 5C4H2-S (or 1435/0445 if 2425 is always treated as BAL)
......(...)
...3♣ = MIN, 4 H, no tolerance for S
......P = < GF, C tolerance
......3♦ = GF relay
.........3♥ = 6+C4H
.........3♠: does not exist
.........3N = 5C4H (so 1435/0445)
......(...)
...3♦ = 6+C5H, F3♥
...(...)
...3♠ = MIN, 3 S
...(...)
2N = INV+ relay
...3♣ = MIN, 4 H
......P = was INV only, C tolerance
......3♦ = GF relay
.........3♥ = 6+C4H (and 2- S?)
.........3♠ = 3 S
.........3N = 5C4H2-S (or 1435/0445 if 2425 is always treated as BAL)
......(...)
...3♦ = 6+C5H, F3♥
...3♥ = MAX, 6+C4H (and 2- S?)
...3♠ = MAX, 3 S
...3N = MAX, 5C4H2-S (or 1435/0445 if 2425 is always treated as BAL)
3♣ = 4 S, to play
(...)
Responder will be able to learn about Opener's range and approximate shape without bypassing 3N. All 5-3 and 6-2 spade fits can be found easily, if not always below 3N. For example, the bidding could go
1♣-1♥
2♥-2N(1)
3♣(2)-3♦(3)
3♥(4)-3♠(5)
4♦(6)
(1) INV+ relay
(2) MIN reverse
(3) GF relay
(4) 6+C4H (and 2- S?)
(5) 6+ S
(6) cue agreeing S
.
#29
Posted 2023-January-08, 17:15
Come to think of it, that sounds not too far off from a Lebensohl 2NT. Opener bids 3♣(/3m) with a minimum, after which we may stop below game, and higher answers are natural and show a maximum.
Converting to the above to a (simple) scheme over, say, 1♣-1♥* (showing ♠); 2♥ (reverse) we would have:
- 2♠ - ? (hands that can't make good use of the bids below)
- 2NT - Asks for min/max, with maximum hands showing a feature with 3♦ and up.
- 3♣ - SI in clubs.
- 3♦ - ? fourth suit, probably exactly 5♠, 3-♥, a single (or even half) stopper in diamonds, lacking club support and unsure of 3NT vs 4M.
- 3♥ - SI in hearts.
- 3♠ - SI in spades (self-sufficient suit).
- 3NT - To play.
- 4♣ -
- 4♦ -
- 4♥ - To play.
- 4♠ - To play.
#30
Posted 2023-January-18, 08:58
- 1♣-1M; 2♦ as either a natural reverse or 18-19 balanced, responder must bid 2♥ to ask over which opener bids 2NT with the balanced hand and a feature with the reverse hand.
- 1♣-1M; 2NT as 6(+) clubs, 15-17 and at most a doubleton in support of partner's major.
- 1♣-1M; 3♣ as the BW Death Hand, 15-17 with 6(+) clubs and 3-card support.
Alternatively, they consider:
- 1♣-1M; 2♦ a natural reverse.
- 1♣-1M; 2NT as 6(+) clubs, 15-17 and at most a doubleton in support of partner's major or 18-19 balanced, may have up to 4-card support. Responder bids 3♣ with any hand that wishes to play there opposite the no-fit long clubs option, 3♦ artificial GF asking and higher bids are natural and GF.
- 1♣-1M; 3♣ as the BW Death Hand, 15-17 with 6(+) clubs and 3-card support.
I'm not comfortable attempting to add my 17-19 balanced to the Odwrotka. Opener's 2NT rebid has to force past 3NT to simplify subsequent bidding. Nevertheless the idea of overloading the (forcing!) 2NT rebid is very sound. If we accept that 1♣-1M; 2NT-3♣ means something like "pass with a minimum (for the auction) with long clubs, describe your hand further if not" it is good as free to fold in the 15-17 no-fit hands with long clubs. I think 18-20 or so might fit as well, you'll just have to bid over the signoff. This does harm slam investigation opposite 18-19 balanced.
Using 1♣-1M; 3♦ as '~18-20 with very long clubs' might work as well, but I'm worried about getting to such a high level without showing shape in the majors (well, a 4cM is excluded, but 3-card support isn't). I also still haven't resolved that the Odwrotka means that the sequence 1♣-1M; 2♦*-2X; 3♦ gets us very high opposite a common minor suit reverse.
To summarise, I have several hand types to take care of and several sequences available, and I'm not sure which bids can be overloaded and where to best allocate some options. The hands I need to take care of are:
- 17-19 balanced
- 16-20 club diamond reverse (with or without 3-card support)
- 15-17 long clubs (with or without 3-card support)
- 18-20 long clubs (with or without 3-card support)
Folding the 15-17 and 18-20 clubs hands without support into the forcing 2NT might work quite well. I am tempted to try to squash as many of the 3-card support hands into the Odwrotka since responder will clarify their major suit holding in response - I think this is why a true Polish Odwrotka promises 3-card support. Maybe, 'to keep it simple':
Lastly the article pointed out that over an unbalanced diamond 1♦-1M; 2NT has no natural meaning, and they recommend playing the same structure (but throw out the balanced and minor suit reverse hands). The 3♣ signoff is now a puppet to 3♦, to be accepted only with the 15-17 range. I'm not sure that this is necessary or even helpful (a Gazzilli structure seems to accomplish everything and more) but it does simplify the bidding structure.
#31
Posted 2023-January-18, 10:00
Something else: With ~20 points and a 4414, DD players can presumably rebid 2♥, but in your system that would show 5+ hearts so you would have to treat the hand as balanced, is that right?
#32
Posted 2023-January-18, 10:11
Or were you thinking of a different first round response?
The 2NT (and up) structure is the same as (and borrowed from, as far as I can tell) the unbalanced diamond. It is quite common to play 1♦-1M; 2NT as the BW Death hand in unbalanced diamond systems, which by implication means 1♦-1M; 3♦ denies 3-card support. IMP points out it is better to flip these two, since without support for partner the strong hand is more likely to have positional values in both unbid suits, and therefore this switch rightsides 3NT more often.
#33
Posted 2023-January-19, 02:43
1♣-1♥; ?:
(...)
2♦ = a) H raise b) "22+"
2♥ = c) C+D reverse d) 17-19 BAL
(...)
1♣-1♥; 2♦-?:
2♥ = < INV opposite a), either 4 H or 5H(332) [so likely no Law protection at 3♥]
...P = a), no game interest
...2♠ (and/or 2N?) = b), relay
......2N+ = e.g. NAT
...(...)
2♠ = < INV opposite a), 5+ H, not 5H(332) [so likely Law protection at 3♥]
...2N = b), relay
......3♣+ = e.g. NAT
...(...)
...3♥ = a), to play
...(...)
2N+ = at least a game try opposite a), hopefully infrequent opposite b)
1♣-1♥; 2♥-?:
2♠ = relay (GF)
...2N = d)
...3♣+ = c), e.g. NAT
(...)
#34
Posted 2023-January-19, 04:21
Put differently, this will get us all the way to, say, 1♣-1♥; 2♦-2♥; 2NT and nobody has said much about shape yet.
#35
Posted 2023-January-19, 07:38
After 1♣-1M, bid:
- 2♣: Downgrade mediocre 15-counts (and even some 16-counts, perhaps) with 6(+) clubs and 2- cards in the major suit.
- 2♦: Shows 1) a natural club-diamond reverse; 2) a strong game forcing hand (say 18+, maybe even 19+) with long clubs (with or without support for the major); 3) any traditional 2♣ opener.
- 2NT: Either 1) (good) 15-17 with 6(+)♣ and 2- in the major, or 2) 17-19 balanced, may have up to a 4cM. Game forcing, we use our normal 1m-1M; 2NT-? structure. Note that, by failure to bid a reverse, opener will usually have at least a singleton in responder's major (7330-hands are the main exception).
- 3♣: 15-17 6(+)♣, 3M. Even mediocre 15-counts should be bid this way. Prime hands near the top of the range can be upgraded into 2♦ (option 2).
I've been thinking of just ignoring the diamonds in clubs-diamond reverses and bidding 2NT or 3♣ (depending on the level of support for the major) as well. If I rebid 2NT with, say, a 3=1=3=6 on 1♣-1♥, is it really a distortion to do the same with a 3=1=4=5? Again I can just comfortably downgrade the mediocre 15-counts, and on 16-opposite-8 do I really want to stop in exactly 3♦? Unfortunately this plan hits a snag when it comes to the reverse diamonds with support for the major (quite rare, but still) - e.g. a 16-count 1=3=4=5 on 1♣-1♥. I'm not quite comfortable bidding 3♣ on that, especially since responder might want to investigate a club or diamond slam. But maybe there's no issue, for example with an asking bid:
1♣*-1♥; 3♣*-3♦* (asking, denies a 5c♥):
- 3♥ - Long clubs.
- 3♠ - Long diamonds (so a club-diamond reverse).
- 3NT - Long clubs with a decent spade stopper (so diamond shortage).
#36
Posted 2023-January-20, 02:18
DavidKok, on 2023-January-19, 04:21, said:
Put differently, this will get us all the way to, say, 1♣-1♥; 2♦-2♥; 2NT and nobody has said much about shape yet.
I would be able to reuse my usual relay structures after e.g.
1♣-1♥; 2♦-2♥; 2♠(relay)-?:
2N = BAL, not 3433
3♣ = 5+ C
3♦ = 1444 or 3433
3♥+ = 5+ D
.
(In more detail:
)
Besides, if the a) in
nullve, on 2023-January-19, 02:43, said:
is precisely hands that would raise a 1♥ response to 2♥ in Dutch Doubleton, then you could also just turn
1♣-1♥; 2♦-2♥; 2♠+
into a better version of
2♦-2♥; 2♠+
in Benji/SEF. Better, because Responder has already shown ~ 8-11 and either 4H3-S or 5H(332) and 1♣-1♥; 2♦-2♥; 3♥ would not be the problem sequence that 2♦-2♥; 3♥ is in Benji/SEF.
#37
Posted 2023-January-20, 04:37
#38
Posted 2023-January-27, 02:32
Playing 2♣ as "traditional strong or weak with diamonds" doesn't mean you have to play multi. It isn't great as a preempt (since responder might hesitate to raise, and as you say the opponents get two shots) but it does take away the one level. One thing it does is protect the strong 2♣ opening from destructive overcalls. Other uses for 2♦ (instead of multi and if you don't want to play 2♦ as something contructive) could be a "mini NT" with 5-6♦ (Bailey two bids), weak with both majors (Ekrens), 5-5 major and another (Wilkosz if allowed), diamonds and hearts, or even diamonds and a major.
Systems you may want to look into (similar to the ones you describe):
- An Unassuming Club. This system have a weak 1NT. 2♣ is 6+. 1♣ is natural (if 11-15 then a four card major too) or 15+ NT or any 20+.
- "Polish Club 2020: Expert" (I've also heard it described as Baltic Club). This is a book written by Jassem, and I think it is the system he currently plays. It is basically Polish Club but the Polish 2♣ opening has been put into 1♣. They instead use 2♣ as Ekrens (weak both majors). Seems like the 1♣ is really overloaded, but it might give you some ideas.
- Nightmare. Seems like Polish Club but with weak NT and normal 1M openings. Their 1C is always strong (15+ NAT, 15-17 NT or any GF). They put 18-20 NT into the otherwise natural 1♦ opening.
You also had a question regarding advantages of Polish Club vs Dutch Doubleton. I'm not saying Polish Club is better, but here's some things I'd consider advantages:
1. Removing the weak unbalanced hands from 1♣ makes it a bit more safe to compete as responder when the opponents enter the bidding. You assume opener have 12-14 NT (which you typically do in DD too, but then you're sometimes having problems when opener had the natural 11 count and you're in a misfit). I myself consider the treatment of the weak NT hands as the strongest part of weak/strong club systems compared to other systems with strong NT. Awm argued that opener can't reopen with the weak NT, and that may be true (unless you agree otherwise) but I'm sceptical regarding this in DD (or other "natural" systems) too: shouldn't a reopening double (when responder haven't bid) show something more than a flat minimum with a doubleton in their suit? Does opener have to bid something else with an unbalanced hand, or the 18+ NT (if that is included in the same opening bid)?
2. Opening 1♦/1M is more limited compared to DD. I agree with you that these openings are fine in DD, but when you actually open say 1M you can take advantage of opener having a maximum of 17.
3. The 2♣ opening in Polish is a double edged sword and I know this style get a lot of criticism (especially in American system litterature). In competitive auctions though it is pretty nice having showed your suit from the start, and also you force the opponents to enter at the two-level.
#39
Posted 2023-January-27, 04:48
- It depends on the auction. There are situations where you can (and indeed, must) reopen with a weak notrump, and situations where it's best to pass. There are also situations where you might have an unbalanced minimum that is too weak to keep the auction open with a double, and you may choose to bid instead. I mentioned earlier that a lot of the pressure is taken off of this by being more aggressive in third seat. The 17-19 balanced hands (or 18-19 if you play 15-17 1NT) can bid 1NT/2NT depending on the auction, or might have to double. The level where 17+ balanced hands start doubling coincides with the level where 12-13 balanced hands stop keeping the auction open, but it depends on what partner has shown.
- -
- I'm not surprised the bid has competitive upsides. I do have twin concerns about the Polish 2♣. If it shows [6+ or 5♣4M] I imagine we often end up preempting partner, while if it shows 6+ always the opening is low frequency. The tighter range compared to Precision (11-14 instead of Precision's (10)11-15) reduces this even further. When bid I imagine it might well be a winner (although with the 5♣4M in there maybe more of a double-edged sword?), but I'd rather not have the bid in the system at all.
#40
Posted 2023-January-27, 07:10
The style with 6+♣ or 5♣ and 4M is what I meant when referring to the Polish style. It would be interesting to see statistics on IMP differences where one table opened 1m compared to the other table opening 2m.
Some more systems I forgot to mention which could be interesting to look at:
- Silent Club. By rbforster on this forum. I don't know if there's notes published, but the idea is that you pass with the Precision 2♣ opening (and the three-suited 2♦ opening). Third hand opens lighter than usual to compensate is my guess. The more well defined and less frequent your 2♣ opening is, the easier it should be to pass with it.
- Transfer Responses to One Club with Relays (book by Lyle Poe 2019). He includes all GF bids in 1♣ (along with weak NT, 18-19 NT, 15+ clubs and some weaker hands with clubs). Opening 2♣ is natural 8-14 (so more frequent and also more preemptive than your examples). With 8-10 you have 6+♣ (like a sound weak two). With 11-14 there are some 5431 hands with 5♣ and 4M included, if the club suit is good. Also all 4-4-0-5 and 0-4-4-5 hands are opened 2♣ instead of 1♣. He claims that 2♣ shows 6+♣ 90% of the time, and responder should assume opener has six. To me 8-14 seems like a huge range, but I haven't tried it Overall this system seems quite similar to what you describe (but with transfer responses instead of a negative 1♦).