BBO Discussion Forums: Which conventions on the opponents CCs... - BBO Discussion Forums

Which conventions on the opponents CCs do you gloat the most about, because -
1. They are so bad you know your side will be getting a good result if they get an opportunity to use it?
2. They come up so seldom that the opponents are wasting a good bid which can be used for something else with a higher frequency of occurrence?

Regarding 1, good opponents were hammering me on the 2NT/Unusual 2NT bid promising 5/5 in the minors. I have since dropped it and can now smile when I see it still on others CCs.

Regarding 2, I can smile when I see Muiderberg on the opponents CCs. It comes up so seldom that they are wasting the 2♥ and 2♠ bids. Chanelling these through the Multi 2♦ bid, they lose the weak 2♦ bid which has a much higher frequency of occurrence. The weak 2♦ also has a greater nuisance value than most would care to acknowledge. Not only have you consumed the entire 1-level bidding space, but also half of the 2-level as well.

I used to feel smug when I saw mini-Roman, but pretty much everyone has gotten wise and stopped playing it.

Ghestem often provides some amusement of a directorial nature.

Any convention which its creator has previous for forgetting is probably not one you should play.

In the Acol Club, "strong 2s, no transfers" is usually good for at least a trick a hand whether they bid or not. Of course, when a strong 2 or a diamond takeout comes up, these conventions are great. What I actually like to see most of all is nebulous openings or conventions that I can often bid over with impunity; doubly good since players at my level have rarely discussed what to do over interference.

As an aside, Muiderberg and the UNT 2NT opening are fantastic bunny-killers. If you were scoring poorly with these against random non-expert opponents then you were doing something badly wrong.

Zelandakh, on 2013-June-24, 03:37, said:

I think you misread what I posted.
1. Good opponents were hammering me with U2NT 5/5 minors whenever I used it! So I dropped it.
2. Muiderberg per se is not bad. The bad part is that it comes up so seldom that you are wasting the weak 2♥ and weak 2♠ which comes up a lot more frequently. A weak 2♦, 5-11 HCP has a probability of 2.97% of occurring. Muiderberg has a probability of 1.8% of occurring for the 4 possible hand patterns combined. So you are losing on the frequency of occurrence.

You really should do some reasearch. Chris Ryall's site is great for this sort of thing:-

Muiderberg is listed as 4.2% (2.1% per suit) for a range of 6-10, of which 1 in 4 has a 6 card suit (and would not count playing it strictly).
Standard Weak Twos are listed at 4.5% (1.5% per suit) for a range of 5-11.

By my reckoning, that makes Multi + Muiderberg considerably more frequest than 3 weak 2s, even if you are much more choosy than this base statistic about when to open them (as you should be). I am interested why you get dealt a weak 2 twice as often as the rest of us though - perhaps that cunning ACBL dealer program again?

I do not understand about the 2NT opening. Either the opponents were using it and you had no option to drop it, or you were opening it and must have been doing something wrong to get such poor results (unless "good opponents" means expert opponents).

I am using BBOs deal generator with the following restrictions set:
5X♠/5X♣ 5 - 10 HCP: Odds = 0.45%
5X♠/5X♦ 5 - 10 HCP: Odds = 0.45%
5X♥/5X♣ 5 - 10 HCP: Odds = 0.45%
5X♥/5X♦ 5 - 10 HCP: Odds = 0.45%
And that is where I got the total of 1.8% from.

6X♦ 5 - 11 HCP: Odds = 2.97%

Difference in favour of the weak 2♦ = 1.17%

So if these numbers are wrong, then BBOs deal generator is spitting out the wrong odds.

Regarding the rest of your post:
Once I've revealed my hand via the 2NT/Unusual 2NT 5/5 minors bid, the hand layout is known. Good opponents have demonstrated that they can use the known hand layout to bid and make thin games in the majors by finessing partner for any missing high cards in both majors.

32519, on 2013-June-24, 07:59, said:

Here's an alternative explanation: You don't actually know what the definition of a Muiderberg 2M opening is...

Not to mention the fact that Zel stated that P(multi 2D or Muiderberg 2M) > P(weak 2D or weak 2M) so you're testing the wrong thing...

32519, on 2013-June-24, 07:59, said:

The same is true for a natural 4♦ preempt. I assume you took that off your card too.

Rik

the fact that opps have a CC at all suggest that they have unusually solid agreements, iow bunny-killing bids are less likely to work than against average pairs.

Take a look here for Chris Ryall's methodology and statistics, including probability of a fit. It even includes an extra definition of Muiderberg beyond the link in my previous message (tip: it is not defined as 5-5). And yes, opening two-suited bids does give a lot of information to the opponents. That is why you want the hands to be relatively pure. The same is true to some degree for a one-suited preempt too. Sometimes the denial of space will be more important than the information given because they will be guessing and get it wrong; other times the information will be more useful, either because they guess right or because all roads lead to the same destination; and we could go for a number too. Much of the time it will make no difference.

Sometimes you need to try different styles of opening and advancing before you find the right one. My experience was that every hand that got opened with a Muiderberg 2M opening was worth about 1 IMP beyond the expectation against intermediate opponents, going down to a small gain against advanced opponents. I do not have a large enough sample size against experts to evaluate. That your numbers are so much worse than this is certainly noteworthy. Perhaps you should try it again and post the first 10 hands that come up to evaluate what is going wrong (or the last 10 if you kept all the old records). No cherry-picking though; it is very easy to introduce bias by selecting only "interesting" hands or those that emphasise a particular point.

Flannery is my favorite, because it often provides a roadmap to the defense.

Andersen and Zenkel remarked, in Preempts From A to Z, that many (most?) experts have tried something other than weak 2♦, and have inevitably abandoned whatever it was and gone back to the weak two. They likened it to trying a new toothpaste. Interestingly, about a year or so ago, I changed from the toothpaste I had used for the first 65 years of my life to a new one - and I don't regret it and am not going back.

Mexican 2♦ not only fits well in Romex, it's an integral part of the system, so I don't see Romex players switching to weak 2♦ (or any other use for the bid) any time soon. I suppose it's legit to wonder if anyone ever declined to play Romex solely because they couldn't have a weak (or Flannery, or whatever) 2♦ opening, though.

IMO, it is pretentious to infer the quality of the opponents by a particular convention they use ---or to even have an expectation of a good result if it comes up.

There are many conventions which are bashed herein but ---in capable hands and within context of their other methods --- can be very effective.

I do, however, admit to assumptions that we will have a good round when I hear the opponents discussing stolen bid doubles, or transfers being on above 2c/1nt; and I do project this to assumptions about their overall skill level.

32519, on 2013-June-24, 01:28, said:

A 2♦ opening showing 10-15 HCP and at least a 6-4 pattern in the majors

Zelandakh, on 2013-June-24, 08:40, said:

But -- were you minus the same amount when you opened a Multi? Or when you had a weak 2 in diamonds?

aguahombre, on 2013-June-24, 09:30, said:

Then you would enjoy playing around here, where after (1 or 2♥) - X - (1 or 2♠) the most popular meaning for double is to show spades.

Vampyr, on 2013-June-24, 10:04, said:

Again, you misunderstand. The comment regarded an opening NT and inferference.

Suction. Doubly (in more ways than one...) if "psycho-" or some other adjective is tacked onto the front end. It's the only convention I can think of offhand that leads to +800 or more for us at least 10% of the time.

TylerE, on 2013-June-24, 12:02, said:

If it leads to a good score 40% of the time I'll take the 10% of 800s, particularly at pairs. While I don't play suction, I do play some other things that fall into that category.