[gnasher]

I think that:

Quote

in about half the cases you will suffer by not being able to stop in comfortable 1N or 2M contract.

is a gross overstatement. Most of the time that it starts 1x-1y;2NT, you bid game.

The main disadvantage of this sequence is that it provides very little room for investigating the best game.

[bluecalm]

Quote

then a good estimate of the 18-19 balanced including any 5332, where the 5 is a minor would be about 1.1%.

Yes but this is for one hand and there are two in a partnership so it's 2.2% altogether.
Admittedly they sometimes open before us when we have 18-19 balanced but that won't happen too often.
2.2% is once every 45.5 hands.

Quote

Most of the time that it starts 1x-1y;2NT, you bid game.

It's possible that I made a mistake or run too small a sample but 0-6hcp range is 50% of partner's range when we have 18-19 balanced according to both dmpro and dealer.

Quote

The main disadvantage of this sequence is that it provides very little room for investigating the best game.

Well, in my country people will be in those 1N and 2M 99% of the time if the split is 18-5, 19-5 and 18/9-6 gives them a choice of passing or inviting. It hurts to lose in such a way once every two tournaments. I think it's a major problem.

[jallerton]

bluecalm, on 2012-August-26, 05:21, said:

Yes, very good. Far from elite though (elite is by definition very narrow group -pairs which win major things regularly ).
Only Gitelman-Moss qualify by recent results but they aren't full time players let alone ones spending much time on honing their system.

So according to you, this pair has very good results despite not playing very much and despite playing what you consider to be an inferior system.

Perhaps this means that the choice of basic system is not so important. Better players tend to win simply because they play better bridge than their opponents.

[bluecalm]

Quote

Perhaps this means that the choice of basic system is not so important

I have no doubt this is true.

Quote

Better players tend to win simply because they play better bridge than their opponents.

Yes. System is very small part of it.
Why do you feel this thread benefits from reminding us of this well known fact ?

[gnasher]

bluecalm, on 2012-August-26, 09:55, said:

It's possible that I made a mistake or run too small a sample but 0-6hcp range is 50% of partner's range when we have 18-19 balanced according to both dmpro and dealer.

It's not obligatory to respond on 0-5 counts, and when responder has a very weak hand the opponents will often bid in front of him. If the auction starts

1x (dbl) pass
1x (1y) pass
1x (pass) pass

we won't usually get to 2NT.

Quote

Well, in my country people will be in those 1N and 2M 99% of the time if the split is 18-5, 19-5 and 18/9-6 gives them a choice of passing or inviting. It hurts to lose in such a way once every two tournaments. I think it's a major problem.

From the last ten events you played in, can you find me five deals where:
- One of your side was 18-19 balanced.
- You got to a making 1NT or 2x.
- In American-style 2/1 you would bid 1x-1y;2NT and reach a contract that goes down.

[bluecalm]

Quote

From the last ten events you played in, can you find me five deals where:
- One of your side was 18-19 balanced.
- You got to a making 1NT or 2x.
- In American-style 2/1 you would bid 1x-1y;2NT and reach a contract that goes down.

I play very little bridge lately (posting here while grinding poker on the side is about all bridge I get) but you gave me great idea - I am going to filter all 18-19 balanced from some major events and see how often those hands come up and give trouble "in practice".
I will get back here with the results.

[gnasher]

While we're waiting for Bluecalm's results, here is an intentionally small simulation. I generated ten deals where South had 18-19 balanced or the equivalent, and North was in the 0-5 range, then decided what would happen in 2/1 compared with Polish Club. There was only one deal (no 5) where standard methods had a likely loss, and even that could be avoided by using slightly more intelligent competitive methods.

Using the same code (with a larger set of deals), I found that these form about 0.4% of all deals. Allowing for either player to have the strong hand, that gives us 0.8% of deals.

Here are the hands and my analysis:

1       S: 53
        H: QJ93
        D: T92
        C: Q632
S: QT876        S: J94
H: 72           H: AT54
D: 753          D: KQ6
C: K97          C: JT8
        S: AK2
        H: K86
        D: AJ84
        C: A54
2NT probably makes
--------------------------
2       S: J87
        H: 94
        D: 9532
        C: Q953
S: Q952         S: T64
H: A75          H: QT32
D: AJ6          D: QT84
C: T82          C: K4
        S: AK3
        H: KJ86
        D: K7
        C: AJ76
Standard auction starts 1C-pass-pass or 1C (dbl)
--------------------------
3       S: T5
        H: T9763
        D: KQ95
        C: 52
S: K98          S: A742
H: Q54          H: J8
D: 86           D: T7432
C: AKT94        C: 87
        S: QJ63
        H: AK2
        D: AJ
        C: QJ63
2NT makes
--------------------------
4       S: 986
        H: T532
        D: T73
        C: JT8
S: T743         S: AK52
H: Q874         H: 9
D: J            D: AKQ98
C: Q952         C: 763
        S: QJ
        H: AKJ6
        D: 6542
        C: AK4
Standard auction starts 1C (pass) pass
--------------------------
5       S: 654
        H: T9852
        D: Q
        C: 9652
S: J            S: QT832
H: KJ43         H: A7
D: T9763        D: K52
C: QJT          C: K84
        S: AK97
        H: Q6
        D: AJ84
        C: A73
Unsophisticated 2/1 gets to 2NT or 3H after
  1C (pass) 1H (1S); 2NT
Polish Club gets to 2H.
--------------------------
6       S: J6432
        H: J94
        D: 3
        C: J975
S: 8            S: KQ7
H: KT53         H: Q86
D: KT874        D: QJ965
C: KT3          C: 62
        S: AT95
        H: A72
        D: A2
        C: AQ84
West overcalls 1D
--------------------------
7       S: JT8753
        H: T5
        D: Q73
        C: Q7
S: 6            S: Q92
H: J9632        H: KQ87
D: AT862        D: K94
C: T2           C: A94
        S: AK4
        H: A4
        D: J5
        C: KJ8653
Standard auction gets to 3S-1, but they can make 3H.
--------------------------
8       S: KQ854
        H: T983
        D: 84
        C: 82
S: 7            S: JT96
H: QJ54         H: K7
D: KQJT92       D: 653
C: 74           C: KQ93
        S: A32
        H: A62
        D: A7
        C: AJT65
West overcalls
--------------------------
9       S: 962
        H: JT76
        D: 7
        C: J9864
S: QJ84         S: T73
H: 83           H: KQ4
D: T84          D: KQ965
C: AK73         C: 52
        S: AK5
        H: A952
        D: AJ32
        C: QT
If North responds, standard auction gets to 3H=
--------------------------
10      S: 43
        H: T654
        D: 842
        C: JT76
S: Q96          S: JT875
H: Q92          H: KJ73
D: T9765        D: K
C: AQ           C: K82
        S: AK2
        H: A8
        D: AQJ3
        C: 9543
Standard auction starts 1C-pass-pass

My code:

set ct_all 0
set ct_2nt 0

main {
  if {[2nt_rebid south] && [hcp north] < 6} {
        incr ct_2nt
        accept
  }
  
  incr ct_all
  reject
}

#######################################################################################################################################################
proc 2nt_rebid {hand} {
  set hcp [hcp $hand]
  set ptn [$hand pattern]
  
  # 4333 or 4432, 18-19
  if {$ptn == "4 3 3 3" || $ptn == "4 4 3 2"} {
        if {$hcp > 17 && $hcp < 20} { accept }
        reject
        }
   
  # 5m332, 17-18
  if {$ptn == "5 3 3 2" && ([diamonds $hand] == 5 || [clubs $hand] == 5)} {
        if {$hcp > 16 && $hcp < 19} { accept }
        reject
        }

  # 6m332, 16-17
  if { $ptn == "6 3 2 2" && ([diamonds $hand] == 6 || [clubs $hand] == 6)} {
        if {$hcp > 15 && $hcp < 18} { accept }
        reject
        }
   
  reject
  }

#######################################################################################################################################################
deal_finished {
  puts " Frequency = $ct_2nt / $ct_all"
}

[bluecalm]

I am curious, what program are you using for generating those hands ?

Here are my results:
I decided to do it on Lauria-Versace hands as they open 2D with 18-19 hands so additional bonus will be to see if they get into trouble on "problem layouts" (my initial hypotheiss is that they do).
I have 9172 hands of them. 2D openings occured in 143 of them which is 1.56%. That's less than my guess in this thread.
The opening faced 0-6 range in 52 of cases out of which I am able to pull 49 (I have some strange bug in db and some hands I didn't remove comments on mix up my .lin building process).
I attach link to .lin file with those 49 hands at the bottom of this post.
My quick review of those hands tells me they suffer here and would suffer significantly at matchpoints. Some hands with 2NT opposite 2PC, many bad games which probably could be avoided in other methods.
On the other hand standard system would be much better here because of possibility of passing 1C which comes in handy with say 4 clubs and very weak hand.

Anyway, the problems layout only occurs once every 176 hands (my intitial estimation of 1 in 100 was too pessimistic) and standard system reduced this number even more (as you can pass 1C).
It seems like it's not that bad after all and I overestimated this problem.

Lin file for reference: https://www.dropbox....er.linpart0.lin

[jallerton]

bluecalm, on 2012-August-26, 10:20, said:

I have no doubt this is true.

Yes. System is very small part of it.
Why do you feel this thread benefits from reminding us of this well known fact ?

Because you were claiming that a particular system was inferior because it was not played by "elite" pairs.

[gnasher]

bluecalm, on 2012-August-26, 14:44, said:

I am curious, what program are you using for generating those hands ?

Thomas Andrew's Deal

[bluecalm]

Quote

Because you were claiming that a particular system was inferior because it was not played by "elite" pairs.

I specifically said it's not a proof.
It is however a very strong argument, especially when we talk about full time players and especially the ones willing to work on/change system things.
I believe people like that (Meckwell, top Italian pairs, top Netherland pairs and some more from various countries). If not a single pair from this group plays 1D as 3+ despite coming from various backgrounds there is probably something to it as they showed willingness to work on system a lot and naturally they choose what they think is best (even if it's very small % of their overall playing strength).

We have no way of proving those things and looking at what the best bidders play is one of the best ways to improve our guesses about what works and what doesn't.

[gnasher]

Bluecalm, I think you're underestimating the effect of people's environment and background. Most top players choose a system that they're comfortable with. Usually that means that they play something like the standard system in their country, because that's the system that they've played, and played against, for years, so it's the system that they understand best.

Consider Helgemo-Henless. They are one of the best pairs in the world. They play 15-17, 5-card spades, 4-card red-suits, 3-card clubs. Does that tell us that this is one of the best systems in the world? No, it tells us that they're Norwegian.

Or Balicki-Zmudzinski. They play Polish Club. Because they're Polish.

Until a few years ago, almost all the top American pairs played 15-17, 5-card majors, 3-card minors. Most American experts still do play that. These days we see less of it at the very top level in America, because there has been a move in the direction of strong-club systems. What should we conclude from that?

One possible conclusion is that the top Americans realised that a 5533-system is worse than a 5542-system, but they were too embarrassed to admit that the French and Italians were right all along, so they switched to Precision instead.

Another, more believable, explanation is that they decided that a well-designed strong club system worked better than a natural system. That doesn't tell us anything about the relative merits of two natural systems.

[aguahombre]

Kudos to Gnasher and Han. They tried to make some sense out of the noise.

[MickyB]

If the only difference between a 5533 system and a 5542 system is the choice of opening bid on a 4432 shape, then they are basically the same system. Either way, partner will assume 1D = 4 cards, 1C = 3 cards, and occasionally he will be disappointed. Of the two, I recommend 5533, simply because sometimes opposition will be allowed to play unusual defences to a 2+card 1C opening.

[MickyB]

Theoretically, I prefer 5524 or 5443/5434 [1H with 4H4m and sometimes 4H5m] to 5533/5542, although I've not actually tried playing them

[dcrc2]

Clearly standard responses do lose sometimes when getting to 2NT or 3M, and while those losses may be infrequent they are also entirely unnecessary. Playing transfers or a negative 1♦ allows for stopping low and doesn't require any change to the opening structure. It's difficult to see what advantages standard responses might have to make up for this: in principle you should be better off playing standard when the auction starts 1♣:1♦, but finding example hands where this improves the final contract is going to be even harder than finding ones where you want to play in 1NT or 2M with 18-19 opposite rubbish. So I'd agree with bluecalm that if the field is able to stop low then it's important to play a method which doesn't lose out on these hands. (Of course this is assuming you are always going to open these hands 1♣; if you consider changing the opening bids as well then there is much more give and take involved.)

[phil_20686]

One of the nice things about transfer walsh (option d) is that you can transfer to a major on junk when you don't want to play in 1c, esp vul, and esp at MP, and not fear a 2N rebid.

I really feel that it is a non trivial advantage of the non-fit style of transfer walsh. Another one is 44(32) type opposite a balanced hand with 42 in the majors, but weak, as the non fit style bids 1c-1d-1h-1s and shows opener 44 no interest in game, whereas the fit style bids 1c-1d-1N = showing two hearts, and the spade fit gets lost. These are good at MP imo.

Also, you win a lot pretty much whenever you get to rebid 1N = 18-19, as you have so much more space for slam/strain exploration. I really think concentrating on the hands where you go off in 2N as the down side is silly. The downside is when you miss slam because you couldnt get your 4M-6m hand across very easily after 1c-1M-2N, as partner thought you were 5-4 or something.

[ulven]

bluecalm, on 2012-August-26, 14:44, said:

I have 9172 hands of them. 2D openings occured in 143 of them which is 1.56%. That's less than my guess in this thread.

May I ask you a copy of all 143?

Plan to put lin-file through http://www.bridgecap...downloadDD.html filter and have a further look.

I currently put 18-19 into 2C.

[antonylee]

This is somewhat unrelated to the main discussion but I'd like to take the opportunity to advertise my dealing program, Redeal (https://github.com/anntzer/redeal), which can run the above-mentioned sim as follows:

$ python redeal.py --accept '\
  (17 < deal.south.hcp < 20 and deal.south.shape in Shape("(4333)") + Shape("(4432)") or \
  (16 < deal.south.hcp < 19 and deal.south.shape in Shape("(5332)") and 5 in [len(deal.south.clubs), len(deal.south.diamonds)]) or \
  (15 < deal.south.hcp < 18 and deal.south.shape in Shape("(6322)") and 6 in [len(deal.south.clubs), len(deal.south.diamonds)]))\
  and (deal.north.hcp < 6) and deal.print()' -n100

♠T92♡J972♢AT2♣542 ♠KJ83♡A864♢74♣AJ6 ♠AQ5♡KQ5♢QJ8♣KQT8 ♠764♡T3♢K9653♣973
♠T872♡J654♢6542♣K ♠J93♡32♢7♣J975432 ♠KQ54♡K987♢AKT♣AT ♠A6♡AQT♢QJ983♣Q86
♠63♡J962♢T5♣QJT63 ♠QJ752♡T5♢KJ4♣972 ♠A984♡AK87♢A32♣A5 ♠KT♡Q43♢Q9876♣K84
♠963♡T765♢964♣653 ♠AJ87♡AK32♢J85♣74 ♠K5♡Q4♢AQ3♣AJT982 ♠QT42♡J98♢KT72♣KQ
♠KJ92♡JT53♢9765♣6 ♠T763♡Q76♢QT3♣AJ2 ♠AQ54♡K8♢AK42♣Q73 ♠8♡A942♢J8♣KT9854
♠KQ8654♡94♢T532♣8 ♠T93♡A862♢K98♣Q32 ♠AJ♡T53♢AQ7♣AKT74 ♠72♡KQJ7♢J64♣J965
♠T73♡854♢JT873♣82 ♠652♡KQ32♢9♣K9654 ♠AQ9♡97♢KQ6♣AQT73 ♠KJ84♡AJT6♢A542♣J
♠63♡T832♢KT94♣QT5 ♠Q9♡AQ754♢J♣J7642 ♠AJ82♡KJ9♢Q75♣AK8 ♠KT754♡6♢A8632♣93
♠JT83♡Q5♢J752♣J32 ♠Q7642♡T82♢QT84♣7 ♠AK♡K763♢A93♣AT84 ♠95♡AJ94♢K6♣KQ965
♠A432♡J96♢T4♣8752 ♠J76♡AKT8♢876♣AJ6 ♠K9♡Q52♢AKQJ3♣KT9 ♠QT85♡743♢952♣Q43
<...>
Tries: 23923

100 hands out of 23923 satisfy the given condition, i.e. ~0.4%.

This post has been edited by antonylee: 2012-August-31, 08:58

[han]

antonylee, on 2012-August-30, 16:12, said:

100 hands out of 23923 satisfy the given condition, i.e. ~4%.

Something is off by one digit.