[straube]

The following is/was the basis for Zelandakh's system. I would group it into strong club because the club promises 15+...


1♣ = 15+ natural or 15+ balanced or 18+ any
1♦ = (9)10-17, 4+ diamonds, unbal
1♥ = (9)10-17, 5+ hearts, unbal
1♠ = (9)10-17, 5+ spades, unbal
1NT = (11)12-14
2♣ = 10-14, 6+ clubs or 5 clubs and 4M

[Zelandakh]

Sorry for the confusion. My system is a strong/forcing club with a weak NT - 1♣ is 15+nat, 15+ bal or 18+ any. Because of the 3-way structure it has some similarities to PC but in truth plays much more similarly to a strong club system in practise. Kungsgeten is correct though that I was using SC as an abbreviation for Swedish Club. I was comparing PC with SC and other members of this family of systems.

The point is that if there is no interference there is enough space to unwind everything so the mixture of hands built into the 1♣ opening and 1♦ response are not so important; whereas if the opps interfere Responder can safely bid their own suit knowing that Opener either has residual support or a big hand. And more, that the informtation as to which suit Responder holds is actually useful to the big hand type. This is what I mean by a "one bid hand"; it is a well-known concept in bidding theory and the fundamental basis of SC. If you think this concept is wrong then SC is definitely not the system for you, and by extension also PC.

[Zelandakh]

We cross-posted. That is indeed the opening bid structure straube and as previously written you are correct that it is more strong club than Polish. Note that I essentially still treat a weak NT as a "one bid hand" though; it is just that this time it is on its own as an opening bid. It is also easy to see that the 2♣ opening is a weakness, mixing a one bid type (weak club one-suiter) with a 2-bid type. It is a compromise but the opening remains cramped even after I put some effort in to creating transfer responses and some additional gadgets. In return the other unbalanced openings are super and the 1♣ structure presents certain advantages (you can relay with 18+ and break relays with 15-17, and the extra strength from Relayer gives Responder more freedom with extras). It is all a compromise, same with every system.

[rhm]

Zelandakh, on 2015-February-03, 10:56, said:

The theoretical basis of the PC and SC systems is that a weak NT is a "one bid hand" and works well homogenously with the strong hand type, which by their nature are "2+ bid hands". It does not matter that the weak NT hands are so common because they are effectively being treated as a single hand type.

Whether Rainer's tweaks improve the basic system I cannot say. I see advantages and also disadvantages, the biggest minus being that you are mixing 2 different types of "one bid hand" into 1♣. Most of all his system seems to be a development in the direction of AUC (with a strong NT) and I am not sure it should still even be classified as PC.

Polish club has many variants.

If we look at the one-bid hands (12-14 HCP) most variants of Polish club put into 1♣ we find:

a) all balanced hand with no 5 card major. The only hands I add are 5-4-2-2 hands containing 5 clubs and a 4 card major
b) three suited hands containing diamond shortage 4♠=4♥=1♦=4♣ and 4♠=4♥=0♦=5♣. The only hands I add are 5-4-3-1 hands containing 5 clubs and a singleton diamond.

So I can not see what I am really mixing here.
In fact I could well argue since I am taking out balanced hand with diamond length, I make the one-bid hands more homogenous (Only possible 5 card suit: clubs, 2-4 cards in each major, at most 3 cards in diamonds).

So I have difficulties getting your point.

While I agree that one-bid hands and more-bid hands is at the heart of the whole philosophy behind Polish club (different to your philosophy or AUC mixing 15-17 balanced hands with 18+ hands) there are limits:

Responder uses negative doubles over interference. The corollary is that the weak hand type should reopen if short in intervenors suit, not least to be able to penalize intervenor.
I see little point in letting intervenor play unmolested at the one-level, only because I am in the 12-14 range in the balancing seat and neither do I like putting pressure on responder to act with modest values when nothing fits, because he has to fear he will not get protected by opener otherwise. One-bid and more-bid hands are not absolute. They are subject to bidding level.
I am still playing Bridge.

Rainer Herrmann

[straube]

Basically your club promises either 2+ for any suit other than diamonds or a strong hand. So more homogeneous than traditional Polish at the cost of some freedom making NFBs in diamonds. On a side note,
I'm surprised that your raise of clubs is not a 7-10 sort of raise; it would be welcome to either hand type and would be a frequent winner for finding an early fit.

Just making sure, but by "one bid hands" we're meaning that after 1C (overcall) 2L is a NFB which opener will pass with the weak NT? Is that (more or less) the main attractive feature of this system?

[gwnn]

One bid hand means that you're usually happy with giving your partner one piece of info and letting him decide. Your auction is one example of the principle but opener is allowed to raise with a maximum and a fit. david_c wrote on this: http://dcrcbridge.bl...or-two.html?m=1

edit: Indeed the whole series is a great instructive read, I just reread it all in one sitting. Come back david_c

[antonylee]

Side note re: NFB: you can also play transfers after overcalls, which I did, and is arguably better (with a WNT you complete or -rarely- superaccept).

[rhm]

straube, on 2015-February-05, 10:09, said:

Basically your club promises either 2+ for any suit other than diamonds or a strong hand. So more homogeneous than traditional Polish at the cost of some freedom making NFBs in diamonds.

Correct, but the description fits Polish club as well, including the fact that opener may be weak with shortage in diamonds. There is no difference here between my variant and for example WJ05.
Maybe I am slightly more likely to hold a singleton diamond, but it is not frequent even in my variant.

Quote

On a side note, I'm surprised that your raise of clubs is not a 7-10 sort of raise; it would be welcome to either hand type and would be a frequent winner for finding an early fit.

If opponents interfere that is what a 2♣ means.
But in an uncontested auction I prefer that responder first limits himself by bidding 1♦ first and that 2♣ is game forcing.
It makes slam investigation so much easier and a club raise is not very preemptive and might in fact preempt a strong opener.

Quote

Just making sure, but by "one bid hands" we're meaning that after 1C (overcall) 2L is a NFB which opener will pass with the weak NT? Is that (more or less) the main attractive feature of this system?

answered below by GWNN

Rainer Herrmann

[straube]

gwnn, on 2015-February-05, 10:34, said:

One bid hand means that you're usually happy with giving your partner one piece of info and letting him decide. Your auction is one example of the principle but opener is allowed to raise with a maximum and a fit. david_c wrote on this: http://dcrcbridge.bl...or-two.html?m=1

edit: Indeed the whole series is a great instructive read, I just reread it all in one sitting. Come back david_c

Found this...

DavidC said:

For the two-bid hands, homogeneity is not so important: it is possible to have different rebids showing different hand types. The Swedish 1C opening is an excellent example of this. The one-bid hands are very homogeneous, consisting of a single hand type (11-13 HCP balanced), whereas there is much more variety in the two-bid hands: any shape is possible for the strong option. Many other well-designed multi-way bids work the same way: they have homogeneity in their one-bid hands, but it does not extend to their two-bid hands.

One problem with this sort of opening bid is a lack of flexibility. The different hand types are very clearly separated. So, if opener has a hand which is supposed to be treated as a two-bid hand, it is important to follow up by actually making the rebid which shows the hand. Unfortunately, as we know, not all hands are "pure" examples of one-bid or two-bid hands. A balanced 17-count is certainly not a pure two-bid hand. But if you open a two-way 1C, then this hand is treated as belonging to the strong variant. So if you are unlucky enough to have LHO overcall 2S, say, and responder raise to 3S, you will be in a difficult position. If you pass then partner will play you for a weak balanced hand, but there is no safety in making a free bid either. The lack of homogeneity between the different hand types is the problem here.

So this sort of bid works best when the "strong" hand types are genuine two-bid hands - as pure as possible. Ideally, they should either have overwhelming high-card strength (20+ HCP should ensure that the hand is a two-bid hand) or be very distributional - though in the latter case you need to be careful that you can actually describe the shape well with your rebid. (Single-suited hands are best for this.) In practice, most systems will have to allow some dubious hands into their strong options because of a lack of better places to put them, but clearly the strong option in our favourite example (17+ HCP, any shape) is already rather light, and anything weaker than this would be really asking for trouble.

I think he's paying a compliment to Swedish for having homogeneity in its one-bid hands (11-13 balanced) as opposed to PC including 15-17 club hands. Later he cites the difficulty including strong hands with weak hands...which is (as we've been discussing) it's not always safe for the strong hands to act later. He seems to be favoring a 2-way bid that might be some weak homogenous hands (11-13 bal?) with some much stronger hands (20+ bal or single-suited)...which is not what PC does.

awm went after this 1-bid hand idea by ridding his limited openers of 6+m and 5m/5m patterns such that 1D is 11-13 balanced or 10-15 3-suited. At worst it can be a 5m440. Responder can usually assume at least a stiff in support of his suit. He can then use NFBs or jump to game in competitive (or uncontested) auctions with an expectation of tolerance for responder's suit and without fear of depriving a strong hand of bidding room.

[gwnn]

Quote

. He seems to be favoring a 2-way bid that might be some weak homogenous hands (11-13 bal?) with some much stronger hands (20+ bal or single-suited)...which is not what PC does.

That part was just an example of how you could make the hypothetical opener 1♣=10-13 balanced work better. Indeed, 1♣=10-13 bal/20+ any is a definite improvement on 1♣=10-13 bal specifically. He is (or was at the time or writing anyway) a big fan of Polish club actually if you read his blog a bit.

About the 15-17 hands with clubs, yes, it's not so clear whether they're one-bid or two-bid hands. In general it seems to be best to use your judgement on whether you treat it as 12-14 balanced or 18+ depending on how the bidding goes in competition (in constructive bidding they are very easy to sort out actually). It's a bit like what david_c says, you open 1♣, hoping to describe that you have clubs and your range or clubs and maybe your second suit, but then you could be shut out like say Kxx x AJxx AKxxx (assuming you don't open 1♦ which some PC sources recommend) if it goes 1♣-(1♠)-p-(2♠) you are gonna pass because your hand looks more like a 12-14 NT than a 15-17 club hand. If your majors were reversed, you could x (although it's a bit of an overbid).

[awm]

Where I would disagree with DavidC is on the extent to which one vs. two-bid hands depends on system. In fact I would argue that this is almost entirely an artifact of system, to the degree that the distinction makes no sense without reference (implicit or explicit) to system. To give some examples:

♠Ax ♥xx ♦Kxx ♣KQJxxx is a one-bid hand in a strong club system (opens 2♣) but very probably a two-bid hand in standard american where 1♣ is often a weak notrump.

♠AKx ♥KJx ♦AJxx ♣Qxx is a two-bid hand in standard american and in Polish club, but a one-bid hand if you play Mexican 2♦ or in a strong club system

Even DavidC's 6-5 in the majors hand might be a one-bid hand if playing an old version of symmetric relay precision where there was an opening 2♦ which showed 5+/5+ in the majors and 10-14 high. It really all depends on your methods.

The way I'd put it is, for each opening in your system there is an "expected hand." In general this is the most probable hand type, and it's what partner will play you for when he has no information to the contrary (especially in competition). When you have something close to the expected hand, you have described with a single bid. When you're far from the expected hand, you will often need to bid again, even unilaterally, to describe your holding. Of course this may be uncomfortable (depending on the auction). In general the goal should be to make sure that hands far from the expected hand are rare and have significant playing strength (making it more comfortable to take another call even in auctions where partner has not shown values and the level is moderately high).

The competitive bidding problem (as I see it) in Polish club is that the expected 1♣ opening is a weak notrump, and all the strong hands are sufficiently far from this that they will need to take another call. This is a lot of hands, and some of them are not really strong/shapely enough to bid again at the three-level in comfort. In a strong club system (or Zel's system) the expected hand for 1♣ is a strong notrump (maybe even a "super-strong" notrump if the 1NT opening is 14-16) and thus only hands with a lot of shape and/or really massive strength need to worry about taking another call.

[rhm]

awm, on 2015-February-05, 19:13, said:

Where I would disagree with DavidC is on the extent to which one vs. two-bid hands depends on system. In fact I would argue that this is almost entirely an artifact of system, to the degree that the distinction makes no sense without reference (implicit or explicit) to system. To give some examples:

♠Ax ♥xx ♦Kxx ♣KQJxxx is a one-bid hand in a strong club system (opens 2♣) but very probably a two-bid hand in standard american where 1♣ is often a weak notrump.

♠AKx ♥KJx ♦AJxx ♣Qxx is a two-bid hand in standard american and in Polish club, but a one-bid hand if you play Mexican 2♦ or in a strong club system

Even DavidC's 6-5 in the majors hand might be a one-bid hand if playing an old version of symmetric relay precision where there was an opening 2♦ which showed 5+/5+ in the majors and 10-14 high. It really all depends on your methods.

The way I'd put it is, for each opening in your system there is an "expected hand." In general this is the most probable hand type, and it's what partner will play you for when he has no information to the contrary (especially in competition). When you have something close to the expected hand, you have described with a single bid. When you're far from the expected hand, you will often need to bid again, even unilaterally, to describe your holding. Of course this may be uncomfortable (depending on the auction). In general the goal should be to make sure that hands far from the expected hand are rare and have significant playing strength (making it more comfortable to take another call even in auctions where partner has not shown values and the level is moderately high).

I do not see much of a disagreement, just that you talk about a different aspect.

DavidC looks at it from a system design perspective.

Is it better for example having a strong club system say starting from 16+ , where it might be difficult after a preempt to tell later how strong opener really is or should you use ideally clearly distinguishable types of hands like 12-14 balanced (one bid hands, which will pass over a preempt unless specific circumstances arise like partner making a negative double) and 18+ hands which will bid again even uninvited?

Of course if you mix such hand-types you need to ensure that the hands, which bid again have "enough" strength to do so.
This is difficult since you do not know how high the preempt will be.
Swedish Club has lowered the margins. It is a two edged sword.

Quote

The competitive bidding problem (as I see it) in Polish club is that the expected 1♣ opening is a weak notrump, and all the strong hands are sufficiently far from this that they will need to take another call. This is a lot of hands, and some of them are not really strong/shapely enough to bid again at the three-level in comfort. In a strong club system (or Zel's system) the expected hand for 1♣ is a strong notrump (maybe even a "super-strong" notrump if the 1NT opening is 14-16) and thus only hands with a lot of shape and/or really massive strength need to worry about taking another call.

It is an imperfect world.
Compare it to standard, where somebody could open 1♣ (11-21 HCP) and gets a preempt.
Compare it to strong club, where somebody could open 1♣ (16+), but many more distributions.
Polish club (12-14 balanced or 18+ plus any distribution possible, 15-17 with clubs)

Is Polish club behind or in a better position? It probably depends but from a frequency point of view often you will know opener is 18+ from his first rebid. This is helpful.

In an old BBO thread about weak notrump Fred argued in favour of strong notrump , because it is much easier to play.
His argument was, 15-17 balanced is not really a hand-type which can bid again should opponents interfere. But giving in when you had not shown your strength with 1NT can also lead to disaster.

Rainer Herrmann

[Zelandakh]

I think you are mixing system design with hand type Adam. A weak one suiter is a one bid hand type regardless of whether the system itself forces you to make 2 or even 3 bids to show it. Similarly for a weak balanced hand. Similarly, 2-suiters and very strong hands are not one bid types even if the system has a speciality opening to handle them in one go. In the middle there is a little leeway as to how strong is too strong not to bid twice. System defeinitely plays a role here. If you are opening 7 counts then a 15 is probably too strong; whereas if the opening is 14+ then 15 is nothing special.

The perceived advantage of my system over PC in competition (homogeneity) is offset by the opps being better informed in terms of their overcall style, so I do not see that as a big win for the 15+ version. Where strong club does have an advantage is an uncontested auction and a positive response. I think this is enough to make the structure good even when PC has advantages elsewhere - but I cannot claim either system is generally better.

Rainer's argument about the strong NT hand type not being worth a second bid is also not really relevant for a comparison between my system and PC, since the strong NT hand type is the basic hand type of the 1♣ opening. So there is no more pressure to bid again with this than with a weak NT in PC. Indeed, this is actually more or less true of most systems currently in use at a high level, the one big anomaly being natural with a weak NT.

In this respect I think the potential benefits of playing a structure like mine (or indeed Fantunes) offer more for the Weak NTer than PC does over natural on the strong NT side. But obviously all of these systems have their issues. A perfect system has yet to be invented (and probably never will be) especially if the system also has to pass system regulations and therefore to be playable.

[straube]

rhm, on 2015-February-06, 05:28, said:

I do not see much of a disagreement, just that you talk about a different aspect.
DavidC looks at it from a system design perspective.

I don't understand this because...

awm, on 2015-February-05, 19:13, said:

Where I would disagree with DavidC is on the extent to which one vs. two-bid hands depends on system. In fact I would argue that this is almost entirely an artifact of system, to the degree that the distinction makes no sense without reference (implicit or explicit) to system.

rhm, on 2015-February-06, 05:28, said:

Is it better for example having a strong club system say starting from 16+ , where it might be difficult after a preempt to tell later how strong opener really is or should you use ideally clearly distinguishable types of hands like 12-14 balanced (one bid hands, which will pass over a preempt unless specific circumstances arise like partner making a negative double) and 18+ hands which will bid again even uninvited?

At the point of 1C (2S) ? your partner's hand type is unknown to you.

awm, on 2015-February-05, 19:13, said:

The way I'd put it is, for each opening in your system there is an "expected hand." In general this is the most probable hand type, and it's what partner will play you for when he has no information to the contrary (especially in competition). When you have something close to the expected hand, you have described with a single bid. When you're far from the expected hand, you will often need to bid again, even unilaterally, to describe your holding. Of course this may be uncomfortable (depending on the auction). In general the goal should be to make sure that hands far from the expected hand are rare and have significant playing strength (making it more comfortable to take another call even in auctions where partner has not shown values and the level is moderately high).

The competitive bidding problem (as I see it) in Polish club is that the expected 1♣ opening is a weak notrump, and all the strong hands are sufficiently far from this that they will need to take another call. This is a lot of hands, and some of them are not really strong/shapely enough to bid again at the three-level in comfort. In a strong club system (or Zel's system) the expected hand for 1♣ is a strong notrump (maybe even a "super-strong" notrump if the 1NT opening is 14-16) and thus only hands with a lot of shape and/or really massive strength need to worry about taking another call.

In PC, the strong hand is not rare at all.

rhm, on 2015-February-06, 05:28, said:

Of course if you mix such hand-types you need to ensure that the hands, which bid again have "enough" strength to do so.

After 1C (2S) P P you balance 2N with Qxxx x AKJx AKQx. Certainly many days you will make, but the point is that you are more or less compelled to act because you haven't given the "strong" message yet. Your partner might have been able to act had he known you have a strong hand, might have been able to make a takeout double for you, but he didn't and now you don't know whether partner has closer to 0 or a 10 count.

rhm, on 2015-February-06, 05:28, said:

Is Polish club behind or in a better position? It probably depends but from a frequency point of view often you will know opener is 18+ from his first rebid. This is helpful.

Definitely behind strong club anyway. If the strong club hand balances with 2N he ought to be promising pretty well north of 18+. The strong club hand will often be able to pass having a minimum balanced hand. Message has been delivered. Partner had a chance to react to this message and chose to pass.

rhm, on 2015-February-06, 05:28, said:

In an old BBO thread about weak notrump Fred argued in favour of strong notrump , because it is much easier to play.
His argument was, 15-17 balanced is not really a hand-type which can bid again should opponents interfere. But giving in when you had not shown your strength with 1NT can also lead to disaster.

Absolutely. And some strong clubbers (primarily those who don't employ relays) like to open a strong 2N for the same reasoning. 1C (2S) P P ? and they comfortably pass with 17-18 or so and a balancing 2N might be 21-22. I'm not fond of a natural 2N opening, but this goes to your point of the plus side of announcing good balanced hands before the auction gets competitive. The plus side is your partner will know what you have.

[Kungsgeten]

I have experience with five versions of forcing club systems:

1. Moscito -- 1C as 15+, 1NT 11-14, 10-14 transfer openings, 2C as 6+ suit, lots of relays
2. Precision without a three-suited opening -- 1C as 17+, 1NT 14-16, 5 card majors, 5+ 2C, nebulous 1D which can be 4414
3. Aggressive MAFIA style -- 1C 16+, 1D unbalanced no four card major, 1M 4+ may have longer minor, 1NT 12-15, 2C+ preempts)
4. Precision with natural 2m -- 1C 16+, five card majors, 1NT 14-16, 1D balanced or 4M and (4)5+m, 2m 5+ suit no major
5. Swedish club, explained in previous post

I've also played natural with short club and transfer responses where all 11-13 or 17-19 balanced hand (except when holding a five card major) opened 1C.

The thing I enjoy most about Swedish club is getting the 11-13 NT hand of your chest. To me the 1C opener is 11-13 balanced, and sometimes strong. In fact the strong variant is pretty common, but anyhow. You can often guess if partner is weak or strong, and if you choose not to act and he's strong you could go wrong (as discussed in this thread). If you choose to act when is weak, you've achieved what you wanted. If you act when he is strong, that is okay too since a hand that would act against 11-13 balanced probably can force game vs 17+.

Very often when partner, or I, opened a nebulous diamond in a Precision like framework (2 and 4 above) I got the feeling that we had preempted ourselves. When the auction got heated it is very hard to guess whether to compete with a balancing double (or a suit of our own) or perhaps take a shot and hope that opener actually had an unbalanced hand which he could not show. The same was true when playing short club (but now you often also had to act with the 17-19 balanced hand as opener). A lot of this could probably be solved somewhat with better agreements, but anyhow. I also know some people pretend that the nebulous diamond is a weak NT, and treat as that in competition. This is probably a sound idea, but to me there were many boards where opener was unbalanced and things got complicated.

When playing a (weak) strong club with weak NT, like framework 1 and 4 above, you have the problem of separating minimum strong hands from really strong or distributional ones. There's also the thing about the weak NT opening, but that is a double sided sword and I quite like it. In my experience opener often had to act anyway here if holding an unbalanced hand with say 17+ or 18+ hcp, but sure you could pass with some of these hands. Balancing at the 2-level could even be done with minimum hands, which could make things hard for partner.

[mgoetze]

What you have to realize is that Polish Club is a system for the masses, taught even to beginners. You can find a lot of holes in a very simple version of Standard American, and then you can fill them by playing things like Checkback Stayman, Gazilli, Ingberman and so on. In a similar fashion, you can work on improving Polish Club. Just one example: one of my favourite ideas when playing PC was opening 2♦ to show either a weak 2 in hearts, or a strong hand with diamonds. (Very convenient for me since it happens that I also like to play 2♥ as Ekrens.) This cleans up the strong variants after a 1♣ opening nicely.

Anyway, I won't defend PC too much, after all my pet system is Transfer Walsh instead. But I will note that I have almost exactly the same problem when it goes 1♣-(2♠)-p-(p) playing Transfer Walsh if I opened with 18 balanced and 3 spades...

[rhm]

mgoetze, on 2015-February-08, 03:09, said:

Anyway, I won't defend PC too much, after all my pet system is Transfer Walsh instead. But I will note that I have almost exactly the same problem when it goes 1♣-(2♠)-p-(p) playing Transfer Walsh if I opened with 18 balanced and 3 spades...

This was a major point I made before. But somehow people seem to believe Polish Club is particularly vulnerable to intervention.
All I can say is that this is not my experience.
It is not the strong diamond hands which create the issue in my opinion. Since I open with any reasonable 4 card diamond suit and 12-14 1♦ my diamond rebid after 1♣ always show the strong variant.
In both Transfer Walsh and in many variants of PC it is the unbalanced diamond opening, which overloads 1♣.
The more extreme you are the more difficulties you create for yourself when opponents interfere over 1♣.

Don't get me wrong: I am not claiming PC is invulnerable, but it seems to me it does a good job.

Rainer Herrmann

[cherdano]

awm, on 2015-February-02, 19:31, said:

5. As for the Poles doing well with the system, I would tend to discount that a little bit. Certainly Poland is a bridge-loving country with some very good players. But if their system was really so good, why has it not spread outside that part of the world? Are there any top American pairs playing Polish club? Maybe you think Americans are too system-restricted; how about the top Aussies? The Norwegians and Dutch seem unafraid to try some interesting stuff, any of them playing Polish club? I just don't see it much outside the Poles, and there has been plenty of adoption of Meckwell-inspired precision or blue club-inspired methods, or variants of Moscito (where allowed) or versions of T-Walsh making the rounds so it's not like everyone just plays their country's standard. It's also quite possible that because the methods aren't that well-known outside Poland, people don't defend them optimally. Certainly I have seen some disappointing performances from very good players using these methods.

I think you are vastly underestimating how common Polish club (and variants thereof) are across Europe (from Germany eastwards, basically). I bet there are more than 10 times as many top pairs playing Polish club outside of Poland than there are top pairs playing Moscito. Heck, there might be more top pairs in Germany playing Polish club than top pairs playing Moscito.

[mgoetze]

rhm, on 2015-February-08, 07:09, said:

In both Transfer Walsh and in many variants of PC it is the unbalanced diamond opening, which overloads 1♣.

If you are playing Standard American, is it that much easier to bid over 1♣-(2♠)-p-(p) with 18 points and 3433 just because your partner knows you don't have 3442? I claim it is the opposite: the unbalanced diamond opening at least makes it easier for you when the bidding goes 1♦-(2♠)-p-(p), because your partner knows you do not have 3442, whereas with 3433 it is a push.

[mgoetze]

cherdano, on 2015-February-08, 07:48, said:

I think you are vastly underestimating how common Polish club (and variants thereof) are across Europe (from Germany eastwards, basically). I bet there are more than 10 times as many top pairs playing Polish club outside of Poland than there are top pairs playing Moscito. Heck, there might be more top pairs in Germany playing Polish club than top pairs playing Moscito.

Quick survey of the 1st Bundesliga:

Standard: 9
Other standardish systems: 5 (2x 5 card majors weak NT, 4 card majors strong NT, 4 card majors weak NT, Swiss Acol)
2/1 GF (including T-Walsh): 8 (including 1 weak NT and 1 var NT)
Precision: 4
Blue Club or similar: 2
Polish Club or similar: 2

Other:
- 5 card majors weak NT with 1♣ nat or 18+ any and 1♦ nat or 15-17 NT
- 2x 5 card majors weak NT with 1♣ including all 15+ bal and club GF, other unbal GF in 2-level openings

I don't believe anyone has played Moscito in Germany in the past decade.