[aguahombre]

Vampyr, on 2013-July-04, 11:34, said:

This is not strictly true. It is common to talk about "holding a weak two in spades" even when you are not playing an opening weak two. Similarly people talk about holding a weak NT or an Acol Two even if they do not include these among their opening bids.

Excellent point. There is also something in this thread of value to Multi players whose 2M openings are also of the weak 2 ilk...merely different strength from 2D (Those pairs do exist). Those folks might well not want a size inquiry when they open 2M.

[campboy]

FWIW I ran some exact numbers. I'm taking as my definition of weak two that it has exactly 6 spades and no side 5-card or longer suit. This is pretty close to the shapes I open 2♠ on, and has the added benefit that it precludes having more than one shortage.

For a range of 5-11 there are 13718869776 such hands, of which 8619870420 have a shortage somewhere. That's about 62.8% of them. Making the range weaker pushes this proportion down slightly; it's about 62.5% for 0-9 (6995759400/11184476814).

[blackshoe]

Vampyr, on 2013-July-04, 11:34, said:

This is not strictly true. It is common to talk about "holding a weak two in spades" even when you are not playing an opening weak two. Similarly people talk about holding a weak NT or an Acol Two even if they do not include these among their opening bids.

you misunderstand me. I did not say that someone who talks about holding a weak two in spades must necessarily have an agreement to open that hand two spades. I do say that "weak two" describes a particular hand type, and a multi 2♦ does not describe that type.

[32519]

Go and check out these Mathematical Probabilities and Percentages Tables on the Bridge Guys website.

Here is a quote from the document:
The numerous combinations of 52 cards and their probabilites and/or percentages of distribution and/or pattern and/or occurence have been studied by many mathematicians, arithmeticians, probability theorists, and mathematical statisticians. The source of the tables below are from The Official Encyclopedia of Bridge, published by the American Contract Bridge League in the year 1984.

Seems like BBOs deal generator is pretty reliable after all! Once you start adding a specified HCP range to any specific hand pattern the percentage starts dropping.

[sfi]

32519, on 2013-July-04, 23:17, said:

Seems like BBOs deal generator is pretty reliable after all!

Nobody in this discussion is questioning the accuracy of BBO's deal generator. Interpretation of statistics can be a surprisingly tricky science at times though.

[Phil352]

gnasher, on 2013-July-04, 07:16, said:

I used to believe this, but then I realised that I'd never actually experienced this advantage. The hands where it occurs are rare, and when they occur you don't usually have enough for 2NT, and the opponents may be in the bidding anyway. And while we're waiting for the right deal to come along, we're leaking information on all the other deals where we don't care about singletons but we do care about overall strength.

In fact, the only reason I ever played a singleton ask was because Phil King had told me it was best, in about 1988.

Valid points gnasher, I think playing pretty constructive weak 2s (8+ to 11) tips it slightly back towards being slightly more frequent and useful since overall strength is already defined. If playing constructive style I'm not convinced feature ask is any more useful than shortage ask (i actually quite like the Svar convention which covers both shortages/6-4s and maximum/minimum. I ripped this from an old Brogeland card:

Svar:
2♠ = Natural, forcing one round (2NT, 3♥ and 3♠ is passable)
2NT = Asks for shortage and another suit
3♣ = Natural, GF
3♦ = Natural, GF
3♥ = Natural, GF (preempt over 2♥, which may be raised to game with at least 6-4)
3♠ = Preempt which may be raised to game with at least 6-4/Splinter over 2♥
3NT = To play (2NT followed by 3NT suggests to play)
4♣ = Splinter
4♦ = Splinter
4M = To play, no forcing pass.


2♥ – 2NT
3♣=6-4, 3♦ ask 3♥=♣, 3♠ = ♦, 3NT = ♠
3♦ = Shortage in a minor 3♥ ask
3♥ = Min with no shortage
3♠ = Shortage
3NT = Max with no shortage
4♣= Void
4♦= Void
4♥= Void in ♠

2♠ – 2NT
3♣= 6-4, 3♦ ask 3♥= ♣, 3♠ = ♦, 3NT = ♥
3♦ = Shortage in a minor 3♥ ask
3♥ = Shortage in ♥
3♠ = Min with no shortage
3NT = Max with no shortage
4♣= Void
4♦= Void
4♥= Void
4♠ = Void in ♥, min

[fromageGB]

32519, on 2013-July-04, 23:17, said:

Once you start adding a specified HCP range to any specific hand pattern the percentage starts dropping

I think what we are concerned with here is the usefulness of having a shortage ask, which boils down to the probability of having a shortage when you have a weak 2, not the probability of having a weak 2 in the first place, so the point range doesn't come into it.

Forget the multiplication by 9, that's confusing, caused by your confusion in post #21 where you multiplied 2.97 by 3. Keeping it simple, on your post #25's figures, corrected in manudude's post #29 for just 6 spades, rather than 6-13, the probability of a weak 2 in spades is 2.38%. Given this hand, a shortage in clubs is 0.57%. You could have a shortage in diamonds, and that is also 0.57%, and hearts is 0.57% too, so on the face of it the probability of any shortage is 0.57% * 3 = 1.71%. This is a bit of an overstatement, because the 0.57% that includes a shortage in clubs will also include rare hands that have a shortage in diamonds as well as a shortage in clubs (etc) so these are double-counted. So bring that shortage figure down from 1.71% to 1.68% (just a guess). The probability of a weak 2 in spades with any shortage = 1.68%. This means that the probability of a weak 2 in spades with no shortage = 2.38-1.68 = 0.70%, considerably smaller.

So when you have a weak 2 (in spades or any suit, the suit does not matter), the chance of a shortage is 1.68/2.38 = about 70%.

This means that a shortage ask is certainly to be considered, and can be useful. However, I believe it pales into insignificance compared with the trick taking difference effect of a wide point range, particularly a vast range such as 5 to 11. What might be useful is a combined method, where the 2NT inquiry commits to game opposite a top end, but depends on the right shortage opposite bottom end. eg 2♠ 2NT :
3♣/♦/♥ = shortage 5-8 hcp
3♠ = no shortage 5-8
3NT = AKQxxx no shortage
4♣/♦/♥ = shortage 9-11
4♠ = no shortage 9-11

[manudude03]

FWIW, I just did some number crunching on the generator with slightly stricter criteria.

6 spades, 0-4 H/D/C 5-11 HCP: 2.16%
6 spades, 0-4 H/D, 0-1 C 5-11HCP: 0.45% (you won't ever have another shortage, 6+1+4=11, so the 4th suit can only be as short as 2)
0.45*3=1.35%
1.35/2.16=62.5%

Those hands being double-counted were more than I thought.

[campboy]

manudude03, on 2013-July-05, 05:52, said:

Those hands being double-counted were more than I thought.

I don't think the double-count hands make much difference. The main problem with the original simulations is that they include all the hands with a 7-card suit, which are much more likely (about 85%) to have a shortage.

[manudude03]

campboy, on 2013-July-05, 06:15, said:

I don't think the double-count hands make much difference. The main problem with the original simulations is that they include all the hands with a 7-card suit, which are much more likely (about 85%) to have a shortage.

The second set of numbers I used was for exactly 6 spades (but everything else in range ok), and the percentage has dropped about 10%. In fact thinking about it, I guess it shouldn't be that much of a surprise, as those 6511 hands and such shouldn't have been counted at all, let alone double-counted.

[32519]

OK, lets wrap up this thread:
Firstly the good news is that we've now discovered that the BBO deal generator is fairly decent.
Secondly let's take the suggestion below and extend it to ♦ and ♥ as well.

fromageGB, on 2013-July-05, 05:07, said:

This means that a shortage ask is certainly to be considered, and can be useful. However, I believe it pales into insignificance compared with the trick taking difference effect of a wide point range, particularly a vast range such as 5 to 11. What might be useful is a combined method, where the 2NT inquiry commits to game opposite a top end, but depends on the right shortage opposite bottom end.
E.g. 2♠ 2NT :
3♣/♦/♥ = shortage 5-8 hcp
3♠ = no shortage 5-8
3NT = AKQxxx no shortage
4♣/♦/♥ = shortage 9-11
4♠ = no shortage 9-11

Over 2♥ we employ "Step Shortage/Range Ask" as suggested by Barry. Now we have -
2♥-2♠ (the asking bid)
2NT = ♠ shortage 5-8
3♣/♦ = shortage 5-8
3♥ = no shortage 5-8
3NT = AKQxxx no shortage

Over 2♦
2♥/♠ = No fit for ♦, non-forcing (scores better than 2♦)
2NT = Direct invite to 3NT when opener is max or holds the top 3 honours, non-forcing
3♣ = No fit for ♦, natural, non-forcing

I think I will be adopting this idea from fromageGB. You got my vote for this. Thanks.

[nige1]

Multi 2♦ - 2N -; ??

• 3♣ = Artificial: Strong variant (e.g. strong 3-suiter then further relays).
• 3♦ = Transfer: Min weak 2 in ♥.
• 3♥ = Transfer: Min weak 2 in ♠.
• 3♠ = Artificial: Max weak 2 in ♥.
• 3N = Artificial: Max weak 2 in ♠.

[nige1]

# weak2 (Just practising Dealer Scripts).
weak2 = hcp (north) > 4 and hcp (north) < 10 and 
shape (north, any 64xx + any 63xx - xxx6)
shortage = shape (north, any 0xxx + any 1xxx)
action average weak2, average weak2 and shortage

About 4.3% of your hands are undisciplined weak 2s.
About 2.7% of your hands are undisciplined weak 2s with a shortage.

[awm]

I'm amused that you are so enthusiastic about FromageGB's method when the Italian-style method wank and I play seems so clearly superior. In particular we can:

1. Find shortage and strength and then select 3nt as a contract.
2. Find shortage and strength and still have the whole 4-level to cue for slam.
3. Avoid revealing the shortage in most cases where partner just wants max/min.

[Bende]

Phil352, on 2013-July-05, 02:38, said:

(i actually quite like the Svar convention which covers both shortages/6-4s and maximum/minimum. I ripped this from an old Brogeland card:

Svar:
2♠ = Natural, forcing one round (2NT, 3♥ and 3♠ is passable)
2NT = Asks for shortage and another suit
3♣ = Natural, GF
3♦ = Natural, GF
...

"Svar" means "responses" but I still like it as a name for the convention .

[32519]

awm, on 2013-July-06, 00:13, said:

I'm amused that you are so enthusiastic about FromageGB's method when the Italian-style method wank and I play seems so clearly superior. In particular we can:

1. Find shortage and strength and then select 3nt as a contract.
2. Find shortage and strength and still have the whole 4-level to cue for slam.
3. Avoid revealing the shortage in most cases where partner just wants max/min.

I prefer fromageGB's method for a number of reasons:
1. Less artificiality (less likely to forget what the bids mean in extended matches when mental fatigue sets in).
2. Bidding shortness with a max on level 4 is equal to a splinter bid. Nearly all from intermediate upwards play splinter bids. So there is no ambiguity about the bid and you are less likely to forget what the bid means.
3. With shortness and a max you don't want to play in 3NT. You want to play in a suit contract.

[Phil352]

Bende, on 2013-July-06, 01:05, said:

"Svar" means "responses" but I still like it as a name for the convention .

mea culpa but i think it should be called that from now on.

[fromageGB]

awm, on 2013-July-06, 00:13, said:

I'm amused that you are so enthusiastic about FromageGB's method...

I'm not, I'm pleased to be of some help
It seems your method cannot identify the shortage in a low range hand, and then decide to play in 3♠ or 3NT depending on the answer. But the key thing for many people is simplicity.

You have a point that it may be better not to disclose a shortage if it is not relevant.

Incidentally, this is not the method I play, as my preferred weak 2 in the majors may be 5 or 6 card, and the replies are simply 2♠ 2NT :
3♣ = weak 5
3♦ = weak 6
3♥ = strong 5
3♠ = strong 6
We did come up with something more complicated that we sometimes forgot, so we dropped it. Similarly as we do not bid a weak 5 when vulnerable, we could have something different for that occasion, but decided that there were more important uses for our limited memories.

[PhilKing]

1. The method chosen should not take you past 3NT unless you have extreme distribution, so jumping to 4m with a max and a singleton is about the worst possible.

2. The method should not give away information prematurely, since partner may just want to invite without tipping off your entire shape.

3. Subsequent auctions need to differentiate between game and slam exploration accurately.

To start with, a range of 5-11 is nuts. You might do OK in a local club game where noone can defend against weak twos, but it is a big leak. It is popular now to split the range - a roughly 8-11 range opens 2M with weaker hands going through a trash multi 2♦. Over an "8-11" 2♠, it can go as follows:

2NT = game relay, spade fit and game try or looking for best strain without fit
3♣ = slam relay. Guarantees at least Qx♠. Continuations are not included here, but we just tend to relay for shortage then either cue or bid RKCB.

Differentiating responders hand-types clears up potential ambiguities later in the auction. After 2♠-2NT:

3♣ = nothing much to say. Then:
.......3♦ = further relay (3♥=6322 3♠/NT/4♣ = stepped shortages)
.......3♥ = nat GF
.......3♠ = nat inv
3♦ = 4♦, decent side suit, else just bid 3♣
3♥ = 4♥, decent side suit, else just bid 3♣
3♠ = 4♣, decent side suit, else just bid 3♣
3NT = 4♣, absolute max, decent side suit, else just bid 3♣
4♣ = 6♠, 5♣, with extreme shape the range is 7-9
etc

The point is, the only hands that don't bid 3♣ are the unusual ones. This way, we rarely give up irrelevant information, but we can still ask for shortage if we want, but only by forcing to game - the cost of telling them partner's shape all the time on invitational hands is just too high. Sure, the system is not perfect - we can't find out about heart shortage without blowing past 3NT, but that's the price of temporary concealment (I could fit it in if I wanted).

[32519]

I can virtually guarantee you that fromageGB's method will skyrocket in popularity once enough people get to hear about it. It's simple, straightforward and requires very little memory load. The bulk of bridge players are club players who neither have the time nor the inclination to spend large amounts of time creating/memorising complicated bidding structures. If you are a high end player competing at the top level, stick to whatever complicated method and partner play. But this scheme will be a hit amongst the lower end players.