Dutch Doubleton write-up?

[Rattius]

Does anyone have a link to a (free) English language write-up of the Dutch Doubleton system?

 

I don't play bridge any more but I occasionally tune in to watch things like the Bermuda Bowl on VuGraph and this system piqued my interest since it seems to solve the problems of short minors in standard 5cM / strong NT systems.

 

Having tried to find something useful via internet searches, I'm aware of the offering on BridgeWithDan but (especially as an ex-player) I'm not really inclined to pay $30 for a 66-page pdf just to satisfy my curiosity.

I'm not sure how comprehensive a 66-page write-up can be anyway, especially when it comes to handling intervention.

 

Thanks in advance.

[straube]

Does anyone have a link to a (free) English language write-up of the Dutch Doubleton system?

 

I don't play bridge any more but I occasionally tune in to watch things like the Bermuda Bowl on VuGraph and this system piqued my interest since it seems to solve the problems of short minors in standard 5cM / strong NT systems.

 

Having tried to find something useful via internet searches, I'm aware of the offering on BridgeWithDan but (especially as an ex-player) I'm not really inclined to pay $30 for a 66-page pdf just to satisfy my curiosity.

I'm not sure how comprehensive a 66-page write-up can be anyway, especially when it comes to handling intervention.

 

Thanks in advance.

 

I think you're thinking about this wrong. Dan has been cataloging many systems and is providing a good service to the bridge community for not much money. Be happy someone has taken an interest in doing so and pay him the small amount of compensation he asks. Or if you don't want to buy it, at least don't come across as devaluing his work. I've read Dan's book on Meckwell Lite and I could tell he put a lot of thought and time into it.

[dokoko]

https://www.bridgebase.com/forums/topic/77336-dutch-doubleton-negative-or-natural-1d/

http://www.tjoen.dds.nl/bridge.html

[Rattius]

I think you're thinking about this wrong. Dan has been cataloging many systems and is providing a good service to the bridge community for not much money. Be happy someone has taken an interest in doing so and pay him the small amount of compensation he asks. Or if you don't want to buy it, at least don't come across as devaluing his work. I've read Dan's book on Meckwell Lite and I could tell he put a lot of thought and time into it.

How did I come across as "devaluing his work"?

 

I may have noted that it's quite expensive for a short pdf file but mainly it's just expensive for an ex-player who is simply curious to know a bit more, not necessarily professional system level. No offence to Dan or his work was intended.

 

All in all, it seems odd that Garozzo (apparently) developed this for the Dutch junior team and it's not documented anywhere. I don't know of any other systems where it's impossible to get a basic write-up somewhere.

[Rattius]

https://www.bridgebase.com/forums/topic/77336-dutch-doubleton-negative-or-natural-1d/

http://www.tjoen.dds.nl/bridge.html

Many thanks dokoko, I'd seen the first thread but it wasn't that detailed on some of the stuff I saw on VuGraph such as some rebids showing 6-4 shapes.

 

The second link was a little difficult to follow - maybe I've been out of the game too long! But thanks for responding :)

[DavidKok]

I'm very familiar with the system and know of many partial writeups, though quite a few of them are in Dutch or not completely accurate. How detailed do you want the answers to be?

[Rattius]

I'm very familiar with the system and know of many partial writeups, though quite a few of them are in Dutch or not completely accurate. How detailed do you want the answers to be?

I was hoping for something quite detailed - enough to follow along on BBO (which could cover any or all of their possible auctions) - and I realise each pair will have somne differednces from standard, but being able to spot and analyse these may be part of the fun. As you touched on in your post, there are concerns over accuracy/provenance of anything that's not written either by the people playing the system or its inventor.

 

Also, the more detail there is, the more easily I can compare it to other systems I know and understand how much coverage it has of hand types etc.

 

Most systems concentrate heavily on uncontested auctions and say little about bids in competition but what struck me about this system (when I heard people like Al Hollander describe individual sequences on BBO) was that they have some really good interesting agreements in competition, such as when opps overcall, and these seem to be part of the standard system.

 

I'm familiar with the various 2/1 styles and I understand that this system takes the concept whereby 1C can be 2 cards (including the 4432 shape that opened 1D in "better minor" styles) but then goes in a different direction by having 1C forcing, eliminating the possibility of playing in a ridiculous 2-1 fit etc.

 

The detail dokoko posted in the second link is fine, just that much of it is in Dutch and I'm not familiar with that notation.

[pescetom]

I play a (non Dutch) style where 1C can be 2 cards in 4=4=3=2 and 1D is always 4+ cards, yet have never played in 2-1 or other ridiculous fits (probably because the only candidate auction is game forcing).

In general, I suspect many of the problems ascribed to short minors are specific to "better minor" and related compromises.

[Rattius]

I play a (non Dutch) style where 1C can be 2 cards in 4=4=3=2 and 1D is always 4+ cards, yet have never played in 2-1 or other ridiculous fits (probably because the only candidate auction is game forcing).

In general, I suspect many of the problems ascribed to short minors are specific to "better minor" and related compromises.

I believe the auction of concern is 1C, passed out. Playing the 1C as forcing removes that issue (and can solve a few other problems too).

[DavidKok]

I'll do a bit of a writeup myself, trying to keep it brief.

 

Opening 4=4=3=2 hands outside the (strong) notrump range with 1♣ has been a popular in the Netherlands for at least half a century now. Historically I think this is called "Dutch Doubleton", but it differs so little from e.g. 3+ 1m openings that it is mostly pedantic to distinguish between them. At some point there was a simultaneous double shift - we restrict 1♦ to 5(+) unless exactly 4=4=4=1, and open 1♣ on all balanced hands outside the range without a 5-card suit outside clubs. For example, 4=3=4=2 gets opened 1♣. This is still explained as "1♣ 2+", but the fraction of hands that have exactly 2 clubs is significantly higher. This saves some bidding space, but also makes it risky for partner to pass 1♣ with a minimum - you might stick partner in a 2-1 club fit while partner has an 18-19 notrump! So people played that 1♣-1♦ showed either a natural diamond response, or any weak hand (traditionally 0-7) with at most 3 clubs. Mind you - 1♣ is not forcing, responder can still pass it out with something like 1-2 points and 5 clubs, taking the view that 1♣ is better than 1NT opposite an 18-19 balanced. The opening bid is also still limited by failure to open 2♣, although it has become significantly safer to open with a strong hand with real clubs. Over a 1♦ response opener would bid their best major suit with 12-14 balanced, assuming partner was running from 1♣ (people were very scared in those days). So:

• 1♥ 12-14 balanced, better hearts than spades, or any non balanced hands (hence 4(+) clubs) with real hearts.
  
• 1♠ 12-14 balanced, better spades than hearts, or any non balanced hands (hence 5(+) clubs) with real spades.
  
• 1NT 18-19 balanced
  
• 2♣ 5(+) clubs, not balanced
  
• 2♦ strong reverse (similar for higher bids).
  

1♥ and 1♠ have to be alerted and can be bid on a 3-piece.

One significant upside of this system is that the 1♥ and 1♠ responses to 1♣ show a sound response. Mind you, the garbage shapely hands still respond, they just go through the fert. This makes it safe for opener to jump with some extras. Conversely if partner presumably does have a garbage hand, opener gets to show 18-19 balanced at the 1NT level.

 

The modern Dutch Doubleton goes a step further in several directions at once. If you slap Walsh onto the previous system you will find that the 1♥ and 1♠ responses are far more frequent than the 1♦ response, which is theoretically a waste of bidding space. Also having both the 1♥ and 1♠ rebid be non-descriptive is awkward. Lastly some people (like me) do not want to open 1♦ even with 5♦332 outside the notrump range. So we stick those opening hands in 1♣ as well, we cram a few rare hand types artificially into the 1♦ response, we force opener to rebid hearts with a balanced hand so at least the spades are natural, and maybe we move the point ranges up or down a bit as we see fit (for example, play a 14-16 NT and shift everything down). To be precise, the opening bids are:

• 1♣ - 'balanced' club - either natural clubs (5+ not balanced) or any balanced hand outside the notrump range.
  
• 1♦ - 'unbalanced' diamond - never a notrump hand, at least 5 diamonds unless exactly 4=4=4=1.
  

Then over 1♣ the responses are:

• 1♦ - one of four hand types - real diamonds (note: if you play Walsh this either denies a major or promises a GF), any 0-7 hand that doesn't want to pass, 6-11 exactly 4=4 majors (we could fit this one in here, but it is important that there is no game opposite 11-13 balanced without a fit) or a strong hand with club support and no convenient bid (in my version exactly 3=3=3=4 10+, where inverted minor could be awkward. All other hands that fit this description have at least 5 clubs, but you might want to glue 2=3=3=5 in there or something).
  
• 1♥ - 8+ points, 4(+) hearts
  
• 1♠ - 8+ points, 4(+) spades
  
• 1NT - 8-10 (remember, weak hands bid 1♦ to not hog the hand opposite 17-19) balanced, tends to deny 4cM, prefers to play the hand.
  

Then over 1♣-1♦ you have:

• 1♥ - any 11-13 balanced or natural hearts+clubs not balanced (4(+) hearts, 5(+) clubs or exactly 4=4=1=4)
  
• 1♠ - 4(+) spades, 5(+) clubs, max 18 (I still play 2♠ as a strong jump shift here, but you can well do without).
  
• 1NT - 17-19 balanced
  
• 2♣ - 5(+) clubs, not balanced
  
• 2♦ - strong reverse etc.
  

If opener rebids a natural suit your normal agreements are in place and the bidding resumes like standard. Over a 1NT response it is easy to play system on, and I do. Over the 1♥ response we need another round of agreements:

• pass - 0-5 with a preference for hearts over clubs
  
• 1♠ - relay, tell me which type you had (answers are 1NT 11-13 balanced, 2♣ 4♥5(+)♣ 10-16 or so, 2♦ artificial 4=4=1=4 or 4=4=0=5 11-16, 2♥ 5♥6♣, 2♠ 4=4=1=4 or 4=4=0=5 17+, 3♣ stronger than 2♣).
  
• 1NT - 4=4 majors 6-11 NF
  
• 2♣ - natural ♦+♣ weak
  
• 2♦ - weak and natural
  
• 2♥ - 5-7 5(+)♥ NF
  

You tend to almost always bid 1♠ so the other bids show hand types that are ill-placed over hearing a 1NT response (over which we play system on).

 

 

I'm not sure if this is the information you were looking for. This does not cover agreements in competition (as a rule of thumb: if they interfere directly over our 1♣, assume 11-13 balanced until proven otherwise), and may not highlight some of the bigger gains (unbalanced diamond is a big winner on competitive auctions, staying low on most 'very strong balanced versus very weak' hands also wins) but I hope it gives some insight in the system.

 

I believe the auction of concern is 1C, passed out. Playing the 1C as forcing removes that issue (and can solve a few other problems too).

In Dutch Doubleton 1♣ is 99% forcing, but responder may still pass. It just doesn't happen very often since most weak hands can be shown, so pass specifically shows a hand too weak to survive 1NT opposite 17-19 balanced but not enough clubs for a preemptive or inverted raise - something like ♠xx, ♥xx, ♦xxxx, ♣Jxxxx. Also, unlike Polish or Precision, a Dutch Doubleton 1♣ opening is still limited (by failure to open a strong 2♣), but you may stretch that to a decent 24-count with long clubs if you like.

[pescetom]

I believe the auction of concern is 1C, passed out. Playing the 1C as forcing removes that issue (and can solve a few other problems too).

 

That's a frequent concern among mediocre players, many at my club have an agreement to never pass 1C (and get indignant when I ask them to alert the forcing bid ;) ).

Of course one should strain not to pass, but if necessary do so, I don't see this as a great issue and not only because of the frequency.

It would be interesting to simulate, unfortunately BBO has broken my preferred tool.

[helene_t]

https://www.bridgebase.com/forums/topic/77336-dutch-doubleton-negative-or-natural-1d/

http://www.tjoen.dds.nl/bridge.html

Standaard Hoog is not dutch doubleton, though.

[Rattius]

That's a frequent concern among mediocre players, many at my club have an agreement to never pass 1C (and get indignant when I ask them to alert the forcing bid ;) ).

Of course one should strain not to pass, but if necessary do so, I don't see this as a great issue and not only because of the frequency.

It would be interesting to simulate, unfortunately BBO has broken my preferred tool.

Er, yeah thanks for the "medicore player" tag. :(

Mediocre players such as Benito Garozzo seem to have been concerned enough to devise a system that avoids the problem, which is good enough for me - I guess birds of a feather and all that ;)

 

All in all, I think it's of concern to lots of people playing matchpoints. But also because of the information it gives to good declarers when an auction starts 1X-P-P-?

 

To say that "one should strain not to pass" doesn't feel right to me - the frequency of a hand in the 0-5 range is sufficient for it to be of concern, especially since the frequency of opening 1C is maximised by including a weak NT, not to mention an 18-19(20) NT in it as well. A weak NT is probably the most frequent opening hand type on its own, never mind the stronger NT hand there's also all the natural 1C openers. This is offset only by the frequency with which LHO overcalls the 1C.

 

And... what are you supposed to do with a 2 count? What is partner supposed to do with a 19/20 count when you choose to do something? I don't think it solves anything to bid that way, it just shifts the problem elsewhere - in that example you end up playing 3NT on a combined 21 with no entries, which is always so much fun.

 

BTW a 2-1 fit was the extreme example - what do you do with 4 clubs - or even 3 clubs - and a weak hand? If partner has clubs, acting can be fatal (and unnecessary) - if he doesn't, you may play a 4-2 or 3-2 fit. Also un-fun.

 

I guess you and I are in different places on this issue :)

[DavidKok]

Those are exactly some of the issues that were resolved with the 'simple' version of Dutch Doubleton, by making 1♦ either natural or a fert. "The Full Dutch Doubleton", as the modern version is called, goes a step beyond that. Unfortunately the simple version doesn't see much play anymore, I think it would be a very helpful stepping stone for many players.

[Rattius]

I'll do a bit of a writeup myself, trying to keep it brief.

 

[sNIP]

Many thanks David. That certainly clarifies the structure of the 1C opening, the gist of which I'd deduced from watching VuGraph, but good to see it laid out. A frequent auction was 1C-1D-1H-1S-1NT where 1S was a relay asking "do you have the weak NT or the natural hand with hearts and longer clubs?". The commentators were not able to say what the continuations were or should be (presumably all weak options looking for the right spot, since there's clearly no game). I was also surprised that this was never doubled (1NT with a combined 12-20, or in some cases 11-19, is as good as saying "Here is my backside, please kick it").

 

The thing that really struck me though was that more than one top pair seemed to have bids available in contested auctions which showed very specific hand types - not that that's unusual in itself for top pairs, the striking aspect was that the pairs playing Dutch Doubleton seemed to be making the same bids, suggesting that it's standard in the system which is unusual and interesting (to me anyway).

 

Unfortunately much of this was back when the Bermuda Bowl was being played, so the details have escaped my memory, but something along the lines of a simple sequence such as 1H-(2C)-2D showed 6-4 in... something, I forget. That example may be well wide of the mark, but the basic idea was that the contested auctions seemed to be well covered in the standard system.

 

If you have any links to even partial write-ups you mentioned, that would certainly be of interest.

[DavidKok]

On the sequence 1♣*-1♦*; 1♥*- 1♠*; 1NT-P responder is only limited by the final pass. In fact, responder more often than not has real diamonds or the 3=3=3=4 10-11 type hand. The fert hands have breakout bids over 1♥, including pass, and will only choose to bid 1♠ relay if 1NT is judged to be playable opposite 11-13. So realistically the combined assets of the partnership on that auction are 16-24.

 

The Dutch partnerships have shared training and coaching, with coordinated system development. I think that might be why they have similar methods even in competition. Unfortunately, I do not know those methods.

The write-ups I mentioned are of the Full Dutch Doubleton system, for example Rosalind Hengeveld's website (in Dutch, but google translate works adequately). Unfortunately this system differs in some significant ways from the version I am familiar with, even if we just focus on the continuations after 1♣.

[pescetom]

Thanks for the clarification, I doubt we are at such different places in the end, even if I am still learning rather than a retired expert.

 

Er, yeah thanks for the "medicore player" tag. :(

Mediocre players such as Benito Garozzo seem to have been concerned enough to devise a system that avoids the problem, which is good enough for me - I guess birds of a feather and all that ;)

Not intended as a put down for you or anyone else interested in these issues :(

Just for those who are terrified to pass when the system says do so.

I don't think Garozzo was worried about the risk of passing an occasional game so much as convinced of the immense potential of forcing with the lowest possible bid, which leads to a different system from those we are talking about.

[and when he did ease off on Strong Club to define a standard 2/1 5cM system, it wasn't the greatest for that matter].

 

 

 

To say that "one should strain not to pass" doesn't feel right to me - the frequency of a hand in the 0-5 range is sufficient for it to be of concern, especially since the frequency of opening 1C is maximised by including a weak NT, not to mention an 18-19(20) NT in it as well.

As you say it is high frequency. "Strain not to pass" to me includes almost all 5 counts, an Ace or even a King and the right hand.

 

 

And... what are you supposed to do with a 2 count?

Pass. 1C it is the least pre-emptive of all bids and the opponent is still there.

 

 

 

What is partner supposed to do with a 19/20 count when you choose to do something?

What exactly is the problem? With 19 over 1Y natural bidding works and with 20 he would usually have opened 2NT anyway.

 

 

BTW a 2-1 fit was the extreme example - what do you do with 4 clubs - or even 3 clubs - and a weak hand? If partner has clubs, acting can be fatal (and unnecessary) - if he doesn't, you may play a 4-2 or 3-2 fit. Also un-fun.

 

I guess you and I are in different places on this issue :)

If the hand does not merit 1NT I can bid a semi-natural 1♦, if partner raises to 2♦ then I can cheerfully signoff in 3♣ as he must have at least 5 card support and we're probably stealing by now.

 

We're at different places mainly because you are used to playing better minor, I suspect :)

I share your interest in the Dutch system and appreciate David's summary.

[Rattius]

Thanks for the clarification, I doubt we are at such different places in the end, even if I am still learning rather than a retired expert.

 

SNIP

No offence taken, thanks for the thought in clarifying.

 

Just quickly, because I didn't want it to become a bidding theory discussion...

 

Re "straining" - doing so on 5 counts only covers 1/6th of the hands in the 0-5 range, so it's not solving the problems.

 

The opponent "may still be there" but they may not be willing or able to act. The fewer clubs you have, the more thay have, making it difficult for them to make t/o doubles or even overcalls (which is the reason a 4-card pre-empt psychic bid works!). Or they may realise what's going on and simply choose to pass to watch vul opps go off in 100s.

 

The reason I mentioned 19/20 rather than just 19 is that many experts feel that it makes sense to play the big NT as 18-20 rather than 19-20 *IF* you arrive at 1NT to show that hand (rather than 2NT as in standard methods) - that's because you now have room to invite, so you can play the wider range. I would certainly take that option since 2NT openers are all pretty much "theoretically unsound" (23hcp required to make 2NT and that doesn't envisage the strength being mostly in one hand) so avoiding a 20 hcp 2N opener sounds like a system advantage to me.

 

And no, I've tended to avoid 5cM systems partly because of their abuse of the minors - I always loathed "better minor"! Here in the UK Acol is what we learn (4cM, 12-14 NT) which is a 100% natural system, if you bid a suit, you have it - although I did play 2/1 some years ago with one partner quite successfully. One of the major advantages to the strong NT is the ability to open 11 counts and rebid 1NT, which is far less prone to being doubled than an opening 1NT with the same cards (although runout methods when a weak NT is doubled are quite sophisticated here so we don't worry too much about being doubled).

 

HTH

 

EDIT: RE the problem with responding on sub-minimum hands opposite big NT hands... if the auction starts 1X-1Y-2NT (often played as a "virtual GF" meaning "pass only if you're sub-min, otherwise any action is GF and shows full values") then you're already too high and the weaker the 1Y was, the worse the problem. In some systems, opener bids 3NT with 19 or a good 18 which is even worse. So in that sense, natural bidding doesn't work, although to be fair the truly "natural" sequence would have been 1C - Pass. Not having to "lie" in this way is actually a big advantage of the DD system (which is why I'm so interested in it!).

[Rattius]

On the sequence 1♣*-1♦*; 1♥*- 1♠*; 1NT-P responder is only limited by the final pass. In fact, responder more often than not has real diamonds or the 3=3=3=4 10-11 type hand. The fert hands have breakout bids over 1♥, including pass, and will only choose to bid 1♠ relay if 1NT is judged to be playable opposite 11-13. So realistically the combined assets of the partnership on that auction are 16-24.

 

The Dutch partnerships have shared training and coaching, with coordinated system development. I think that might be why they have similar methods even in competition. Unfortunately, I do not know those methods.

The write-ups I mentioned are of the Full Dutch Doubleton system, for example Rosalind Hengeveld's website (in Dutch, but google translate works adequately). Unfortunately this system differs in some significant ways from the version I am familiar with, even if we just focus on the continuations after 1♣.

Ah - I hadn't spotted the stronger hands in the 1♦ response, apologies I assumed it was the same as described in the VuGraph commentary where they said it was simply 0-7 (they may have been wrong of course). It certainly makes sense to maintain the possibility that the partnership may have the balance when arriving in 1NT, we can't make life too easy for the enemy. ;)

 

Re "Walsh" - or what US players call Walsh. It's interesting that (I think) good players over here have played that way for a long time without calling it anything - whether they are playing Acol, 2/1, DD or anything else, responding to 1♣ with 5+ diamonds and a 4-card major we would routinely bypass the diamonds unless GF strength. In bidding theory terms this allows responders's reverses to be GF - without that many auctions involving strong hands are simply too clunky to handle e.g. 1♣-1♦; 1NT-2♥/2♠ really needs to be GF. There are far more big hands in total than the relatively tight invitational range -and big hands are more important than smaller ones, so bidding theory tells us to play that way. I used to see a lot of players responding 1♦ with less than GF values though, so perhaps it would be better if we did have a name for it over here! :)

 

Thanks for the links as well David, much appreciated.

[helene_t]

The English sniplets of DD that float around on the internet are as far as I can see based on a somewhat dated style in which

1♣-1♦

1M*

shows 3+ cards, as in most Polish Club styles.

 

Nowadays the fashion is

1♣-1♦

[1♥*

with any 12-14 bal, so that 1♠ would show an unbalanced hand as in Walsh. Also

1♣-1♥

1♠*

shows an unbalanced hand in modern style.

[Rattius]

I'll do a bit of a writeup myself, trying to keep it brief.

SNIP

I just noticed the up-/down-vote system and I went to upvote your post above David, but it won't let me do that (says I've already used my quota for the day).

 

Is there something to know, such as new posters can't vote?

[helene_t]

I just noticed the up-/down-vote system and I went to upvote your post above David, but it won't let me do that (says I've already used my quota for the day).

 

Is there something to know, such as new posters can't vote?

Yes you need a certain number of posts (maybe 50 or 100?) before you get voting rights.

[helene_t]

I believe the auction of concern is 1C, passed out. Playing the 1C as forcing removes that issue (and can solve a few other problems too).

This is a concern (unless you play a Mexican 2♦ or similar so that playing 1♣ in a 2-2 fit implies that the board belongs to the opponents) but actually I think the problem is smaller in a short club system than in other natural systems, because usually someone can bid over a 1♣ opening.

 

Some DD pairs play 1♣ as forcing so that it can include some very strong 3-suited hands (or maybe any GF hand with primarily clubs), but there are also advantages of allowing responder to pass with say 0-4 points and 4+ clubs. For one thing it takes a bit of the pressure of the 1♦ response. Another thing is that if 1♣ is forcing, opps can afford to pass with certain strong hands. For example they may agree that a balanced 16+ count passes first and decides whether to come in in next round, so that a direct 1NT overcall is something artificial.

[Rattius]

On the sequence 1♣*-1♦*; 1♥*- 1♠*; 1NT-P responder is only limited by the final pass. In fact, responder more often than not has real diamonds or the 3=3=3=4 10-11 type hand. The fert hands have breakout bids over 1♥, including pass, and will only choose to bid 1♠ relay if 1NT is judged to be playable opposite 11-13. So realistically the combined assets of the partnership on that auction are 16-24.

Having had time to read your system post more carefully and think about it, the 4 options in the 1♦ response don't seem to offer as much protection as it might appear, because they would all "have done something else" by the time 1♣*-1♦*; 1♥*- 1♠*; 1NT - P happens.

 

As you say, at that point it's known that he has 0-7 (or 0-6 as some top pairs seemed to be playing on VuGraph) and if the weak NT is 11-13 then our man in the pass-out seat knows they have only 11-20 hcp.

 

So I'd deploy a defence such as Lionel (by Lionel Wright, former world pairs champion) in the pass-out seat - and possibly over the 1♠ relay as well. Using double to show 11+ with ♠ & another (at least 4-4) allows partner to either compete the part score, or to pass whenever we have the balance (and we have the advantage of the opening lead). There are probably other defences that would achieve the same thing, possibly even more penalty-oriented than Lionel. Knowing that we have at least as much as they do and that we get to strike first means, to my mind, that double is almost automatic here especially against vul opponents.

 

This look like a system weakness - in a standard strong NT system, when we open with the weak NT hand we get to make at least 1 natural bid (the response) which can make it easier to find an escape route. With DD, there are no natural bids at all in the 1♣*-1♦*; 1♥*- 1♠*; 1NT sequence, so effectively you've simply opened an 11-13 1NT at any vulnerability and responder's hand is known to be very weak. However, at least responder gets a chance to run, which they don't get after an opening 1NT - (X*) - P - (P**) - ?

 

where

* = 11+ ♠ & another

** = pass to play 1NT doubled with 10+ hcp.

 

In that scenario opener is in the pass-out seat, suddenly lumbered with the last decision and has no knowledge of his partner's hand - since partner may not have acted because he didn't know if they were about to contest the part score or wield the axe.

 

 

In Dutch Doubleton 1♣ is 99% forcing, but responder may still pass. It just doesn't happen very often since most weak hands can be shown, so pass specifically shows a hand too weak to survive 1NT opposite 17-19 balanced but not enough clubs for a preemptive or inverted raise - something like ♠xx, ♥xx, ♦xxxx, ♣Jxxxx. Also, unlike Polish or Precision, a Dutch Doubleton 1♣ opening is still limited (by failure to open a strong 2♣), but you may stretch that to a decent 24-count with long clubs if you like.

What I understood from commentary is that there's 2 versions of the system, forcing and "semi-forcing", with the latter being as you described.

 

It also struck me at the time that in the forcing variant, some big hands don't need to open 2C unless they are confident of handling the development of the auction. Hands that would rebid 3 minor are among the worst - bidding space is at a self-inflicted premium. Also 2♣ openers tend to attract interference from good opps so it can become uncomfortable on any hand type - my least favourite auctions are along the lines of: 2♣ - (2♠) - P - (4♠) - ?

 

It also gives breathing room to a small number of really awkward strong hands with clubs, something like AQxx K AQ AQJxxxx - I'd open this 1♣ but I'd feel much happier knowing I'll get another go.

 

Apologies, I seem to have got drawn into the theory - and written rather a lot here for someone who hasn't played the game in years!

[Rattius]

This is a concern (unless you play a Mexican 2♦ or similar so that playing 1♣ in a 2-2 fit implies that the board belongs to the opponents) but actually I think the problem is smaller in a short club system than in other natural systems, because usually someone can bid over a 1♣ opening.

 

Some DD pairs play 1♣ as forcing so that it can include some very strong 3-suited hands (or maybe any GF hand with primarily clubs), but there are also advantages of allowing responder to pass with say 0-4 points and 4+ clubs. For one thing it takes a bit of the pressure of the 1♦ response. Another thing is that if 1♣ is forcing, opps can afford to pass with certain strong hands. For example they may agree that a balanced 16+ count passes first and decides whether to come in in next round, so that a direct 1NT overcall is something artificial.

 

Yes I can see there are advantages to passing with clubs and a weak hand and also advantages to playing it as forcing to push some big hands through that route. I remember the BBO commentator making the point re big hands being able to pass over a forcing 1♣ and come in later, although they have to give up some competitive sequences to do so. What strikes me is that a strong NT hand will often have clubs, so any risk involved in a trap pass is limited.

 

Re the "2-2 fit" scenario, I actually see it the other way round. Theoretically, the fewer clubs the opening side has (after opening 1♣) the more clubs the opposition has, therefore the less likely it is that they can make a t/o double - because if they both have 3+ clubs they are not shape-suitable for a double, so double would only be an option for the (rare) stronger hand types. They are also less likely to have length in other suits, with spaces being taken up by clubs, so the chance of an overcall is reduced too, but perhaps only a little.

 

In practice, you don't see too many problems with 1♣ openers being passed out in standard strong NT 5cM systems, but I see opponents being too willing to bend their protective bids out of shape, which I don't think is necessarily wise when opponents are playing a system like that. However, a system weakness is always there no matter how often you "get away with it" and has a way of manifesting itself at a bad time. I noticed years ago that the higher the level you play, the more perceptive the opponents become and as I type I'm recalling a national final which we won by 10 IMPs, partly due to a 13 IMP swing in due to opponents having a problem hand type which we understood and exploited (not a hand type directly related to this discussion though - although it was a consequence of a nebulous opening bid).

 

But... I'm aware that I'm probably getting too involved in the bidding theory for someone who doesn't play the game and was just looking for a system write-up!

 

P.S. Thanks for the info re number of posts required to vote :)