Author Topic: How often do Conventions come up?  (Read 2749 times)

DickHy

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How often do Conventions come up?
« on: April 17, 2022, 11:12:05 AM »
Occasional comments at the table about the usefulness of conventions prompted the inner geek to record hands over the 9 months.  Perhaps the results are of interest? 

I play 2/1 with a strong NT with my regular partners.  We don’t use Gazzilli or XYZ.  On 1081 hands we opened the bidding.  Here’s the breakdown by opening bid; 1M 324, 1m 479, 1N 140, 2N 15, Weak 2 61, 3x/4x 37, 2C 25

For the 324 1M openers, here’s how often conventions came up:

51: 2/1 (3c M support or other GF)
23: Bergen (4c M support, not GF)
10: Picture Bids
10: Jacoby 2N (4c M support GF)
8:  Game Try (long and short)
4:  4SF
3:  Splinter

I’m not promoting conventions or saying that this is the right suite.  I like Bergen because 54 fits play much better than 53 fits, but I know it’s criticised for landing 20/20 hands in 3M.  Having spent some time learning about Picture Bids, it was gratifying to see them come up as often as Jacoby 2N (which we all learn once we’ve weaned off the breast it seems).

For the 479 1m openers:

38:  Inverted minors
24:  Support x/xx
15:  4SF
7:  Checkback
7:  2/1 (only over 1D)

Support x/xx strike me as great as long as partner has a 5c M, but can cause trouble when she/he is searching for a bid when holding only 4.  Of course, I arrange these situations so that it is always my partner who plays the Moysians.  Nonetheless, support x/xx were useful for us intermediates.


For the 140 1N openers:

22:  Stayman
20:  Major suit transfer (2-level)
6:  Lebensohl
4:  Texas
4:  Minor Suit transfer
3:  Smolen
1:  Super-accept

My partners and I limit super-accepts to 4c support and max, which I personally think is too restrictive.  Oliver includes a range of super-accepts in OCP (I think) and I’ve seen many variations on vugraph.  It’s probably a topic to explore, so the statistic here could be misleading. 

Because we use a strong NT, we didn't get overcalled very often, so the very useful Lebensohl is under-rated by these stats.  If I could persuade my partners to play mini-NT green v red, I imagine Lebensohl would be much more important.

An aside: I like 2-way minor suit transfers [1N – 2S = clubs, 1N – 2N = diamonds] because opener can super-accept when holding Axx, Kxx or Qxx in the minor with the intervening bid [1N – 2S – 2N or 1N – 2N – 3C].  The statistics probably are right in this case, because I think 2-way minor suit transfers should not be used routinely when holding a 6c m.  In fact, there are three particular cases when they pay off:

1) Very weak hands, where 3m will be less disastrous than 1N.  (Hands like: xx xx Kxxxxx xxx or x xx xxx Qxxxxxx or xx xx Qxxxxx Qxx)

2) Weak invitational.  These hands are not the usual 8/9 HCP invite hands after a strong NT opening.  Instead, if opener has got the missing top honour, the minor suit will provide 6 tricks.  It is surprising how often 9 tricks can be won when responder has only 5 or 6 HCP.  Hands like: xx xxx KQxxxx xx or x xxx xxx AQxxxx

3)  Slam Interest.  These hands are strong enough to make 3N, but if opener has support for the minor, a slam is likely.  Again, like the invitational hands, slam can be made on less than the “usual” strength – 14 HCP opposite 15-17.  Hands like: x Axx Kx AQxxxxxx or Kx Axx xx KQxxxx

Whatever opener bids after 1), responder signs off in 3m.  If opener super-accepts after 2) or 3), responder bids game or slam (respectively), otherwise passes 3m or bids 3N (respectively).  Normal invite hands (8/9) and normal GF hands (10-13) should forget minor suit transfers and just simply aim for 3N.


OK, sorry for that mad digression: back to the stats and just to finish the opening hands.  RKC was used 18 times in these 1081 offensive hands, the Queen Ask 3 times, Exclusion twice.   After the 61 Weak 2 openings, Ogust/Feature Ask was used twice, a fast raise 37 times.

On 1099 hands they opened the bidding (they were playing strong NT): 1m/1M 825, 1N 149, Weak 2 68, 2N 31, 3x/4x 26

For the 825 1m/1M openers, we used;

43:  Two-suited overcall
35:  Weak Jump overcall
29:  1N overcall

I’ve not included simple overcalls, because they come up loads and are not really a convention. 

For the 68 Weak 2 openers, we used;

21:  Lebensohl
5:  2N overcall
1:  Michaels

Lebensohl has caused my partners all sorts of brain-aches, but I love it (but then I really liked the transfer Lebensohl Oliver uses) and it’s pretty simple – and came up often.

For the 149 1N openers, we used Cappelletti 28 times to show suits and doubled 7 times to show balanced strength.  Our opponents always used a strong NT.  Against weak or mini-NT some overcall from us would have been far more frequent.

That’s a lot of words for possibly not much useful material, but at least it means I’ve finished this little project.
   

kenberg

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Re: How often do Conventions come up?
« Reply #1 on: April 18, 2022, 01:41:52 PM »
The numbers are interesting.

I found the responses to 1NT a bit surprising. There are 140 1NT openings and 60 responses listed. I assume that the other 80 times the response was Pass. That's more often than I would have expected but I have never thought that much about it.

One of my thoughts about conventions is "what is gained, what is lost?" And then "How often does it matter".

Example: In the 1081 hands there were 324 1M openers, that's quite a few. And then 23 Bergen responses. But there are other uses for 1M-3m if not playing Bergen.

At a more primitive level, I will be playing in an hour or so with someone who does not play 2/1, it's more like SAYC. We will be playing 16 boards and from what I have seen it seldom matters that we are not playing 2/1. It can affect the auction and, of course, sometimes alters the final contract but not really very often. somewhere I have some comments from Mike Lawrence about that. As I recall ML thinks that playing 2/1 is something of a disadvantage in partscore auctions, is usually inconsequential in game hand auctions, and is very useful in slam auctions.

The guy I am about to play with also likes Flannery so we play it. My main objection to Flannery is that I think the weak 2 !d call is very useful when it comes up. You mention 68 weak 2 bids so I suppose about 33 were weak 2 !D bids. We would lose those. We get Flannery and yeah, I guess it has its uses, but I like having the weak 2 !D available.

Anyway, the results are interesting.


Ken

jcreech

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Re: How often do Conventions come up?
« Reply #2 on: April 18, 2022, 03:41:28 PM »
Hi Dick,

I agree with Ken, this is very interesting summary that you have produced.  And the approach leads to thought about how to improve my own choices of which conventions to adopt or reject.

What I am inclined to do is consider all of my favorites on a side-by-side basis and compare which choices would be used and also consider whether the choices would lead to the best level and strain.  For example, with the 2D bid that Ken used as an example, I would compare a weak two, Flannery, Action two, mini-Roman, and multi, but in each instance, I would also have to compare the system as a whole with the various choices, so it is clearly not an easy to accomplish task.  For example, the weak two, Flannery and mini-Roman would all be considered under a weak NT and a strong NT system - so six comparisons, not just three.

Anyway, I appreciate the food for thought.
A stairway to nowhere is better than no stairway at all.  -Kehlog Albran

DickHy

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Re: How often do Conventions come up?
« Reply #3 on: April 19, 2022, 09:20:14 AM »
Ken, Jim,

I'm pleased these figures were interesting.

The missing 1N responses were either pass, 2N or 3N - pretty much evenly split between the three.  With hindsight, I wished I'd separated the 2 !D openers from the 2M openers.  From time to time I think about alternatives for 2 !D and it would have been useful to see how often a weak 2 !D came up - I tend to use it less than a weak 2M, especially if I have 3c M suit (which I tend not to worry so much about when opening 2M - rightly or wrongly).  I was interested in your thoughts about alternatives for a 2 !D opener.

I didn't include Drury.  I think intermediate players don't naturally think of opening light in 3rd or 4th (that's true of me, certainly).  Whereas on vugraph, for example, these light openers are ten-a-penny (and not just 3rd and 4th!), and they seem to work well.  Of course, I guess one would have to compare the outcome of hands with and without light openers/Drury which is more involved than just counting frequencies.




jcreech

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Re: How often do Conventions come up?
« Reply #4 on: April 19, 2022, 01:52:58 PM »
If I am not using 2D as a preempt, I like the mini-Roman that promises diamonds as one of the 4's.  It applies additional pressure on the opponents when your partner could pass (choosing to play in diamonds on a 4-3 or 4-4 fit and poor to moderate HCPs.  If asked for a defense, you just recommend double for takeout and overcall with length.

As for continuations, I play
  • 2H/S as pass or correct to next 4-bagger.
  • 2NT is an ask with the following rebids by opener: 3C show stiff club any size (3D now asks size with 3H showing min and 3S showing max), 3D shows stiff heart min, 3H shows stiff H max, 3S shows stiff spade min, 3NT shows stiff spade max)
  • 3H/S are length showing (6/7) invitations - pass if stiff, raise to game with 4
A stairway to nowhere is better than no stairway at all.  -Kehlog Albran

wackojack

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Re: How often do Conventions come up?
« Reply #5 on: April 20, 2022, 10:39:04 AM »
I have just checked for my own interest DickHy's  figure of 140 out if 1081 for 1N opening frequency against the probablistic stats:
Balanced hands:
Odds of 4-4-3-2 =21.6%
Odds of 4-3-3-3 = 10.5%
Odds of 5-3-3-2 = 15.5%
Total = 47.6%

Odds of getting 12-14 points = 20.6%
Odds of getting 15-17 points = 10.09%
Odds of getting 18+ points = 4.09%
Proportion balanced hands in the 15-17 range = 29%

So chance of an opening bid of 1NT out of other 12 + hands = 0.476* 0.29 = 13.8%

Number of DickHy's non weak opening bids were 963
Number of DikHy's 1NT opening bids were 140
Prportion of 1N opening bids to total non weak = 140/963 =  14.5%

Bearing in mind that some 5-4-2-2 distribuions will be opened 1N and and perhaps some 5M332 distributions in the 15-17 range will be opened 1M, my expected figure of 13.8% is very close to DickHy actual figure of 14.5%.

 



 

kenberg

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Re: How often do Conventions come up?
« Reply #6 on: April 21, 2022, 01:31:26 PM »
Ken, Jim,

I'm pleased these figures were interesting.

The missing 1N responses were either pass, 2N or 3N - pretty much evenly split between the three.  With hindsight, I wished I'd separated the 2 !D openers from the 2M openers.  From time to time I think about alternatives for 2 !D and it would have been useful to see how often a weak 2 !D came up - I tend to use it less than a weak 2M, especially if I have 3c M suit (which I tend not to worry so much about when opening 2M - rightly or wrongly).  I was interested in your thoughts about alternatives for a 2 !D opener.

I didn't include Drury.  I think intermediate players don't naturally think of opening light in 3rd or 4th (that's true of me, certainly).  Whereas on vugraph, for example, these light openers are ten-a-penny (and not just 3rd and 4th!), and they seem to work well.  Of course, I guess one would have to compare the outcome of hands with and without light openers/Drury which is more involved than just counting frequencies.

I have been busy lately so I did not read your stats closely enough. I just looked at the responses t 1NT and thought "I guess the rest are passes, that's a lot of passes". Sure. you listed the conventional responses so the unlisted ones are either passes or raises. Maybe a third are passes. Ok got it.

To go on a bit more, it could lead to a nu ber of things. Lebensohl, for example.  You note 6 uses of Leb. That's 6 uses in 1081 hands and it highlights a problem. Lebensohl after 1NT-interference needs discussion and the infrequency means people think "really, do we have to?' and even if they discuss it they have to remember what conclusion they came to.

For example, 1NT-(2 !H) showing !H. OK Let's say 1NT - (2 !H) -3NT denies a !H stop so, if we want to bid 3NT with a !H stop we go through Leb. But suppose the opponents are playing DONT, so 1NT - (2 !H) shows both !H and !S. What shows what stop, what denies what stop?  With most pards I just play that when the suit they bid I either the suit that they have or one of the suits that they have then Leb is on and refers to the suit they bid. The logic is that it just doesn't come up often enough to worry about. But surely we could do better. For example, one could play that an immediate 3NT denies stops in either major,, going through Leb and then 3NT shows stops in both majors, and bidding 2NT Leb and then, over 3 !C, bidding 3M shows a stop in M and denies a stop in OM. I play this with no one. And of course we ought to discuss what 2 !S means over a DONT 2 !H.  And so on and so on.

And all that is just after a DONT 2 !H.

It's just a fact of life that we, or at least I, play conventions that we have not discussed as thoroughly as we should. I think that in the second edition of Steve Robinson's book Washington Standard there is a table of what means what for 3rd hand after various conventional overcalls of a 1NT opening. I have never played all those meanings with anyone.

There is an old, probably apocryphal, story that after Goren lectured to an audience a man came up to him and said "I agree with you Mr. Goren, when a man bids clubs, a man ought to have clubs, as God intended".  Sometimes I long for the good old days.

But I expect, or at least I hope, to make it to Donna's session today, where we will discuss this and that meaning of this and that convention.  A sense of humor, maybe a sense of the absurd, can be useful.  I enjoy it.

Ken