BBO Discussion Forums: jacoby 2NT and Splinter bids - BBO Discussion Forums

I actually do know about México. 1M-2NT is, if you're really new, Natural. Otherwise, it's J2N the way it's played in the US and Canada, potentially unless your name is Herrera or Reich (but probably even then).

Several have gone to the "3C=any min" set of responses (which is my problem with "J2N" - people will assume the classic responses).

blackshoe, on 2020-June-04, 15:29, said:

Jacoby 2NT is unheard of in Italy, except to those who play online or internationally.
Most play 1M - 2NT as an invitational raise, which brings us to yet another problem of names, some common conventions do not have one!
Everyone here plays Jacoby transfers but most call them 'Texas' and do not play Texas transfers.

Just tell them what it means, as DB would say.

I have an even better weird example of convention naming. Around here, if a pair say they play "Standard American" it means they play a version of Forum D where 1♦ promises 4+ and 1♣ can be opened with 2.

In Norway, 'Tartan' is actually Muiderberg.

Zelandakh, on 2020-June-05, 18:25, said:

That's okay, here in America, it frequently means that too (except "what's Forum D")?

mycroft, on 2020-June-05, 09:12, said:

That is simply awful. Why use your most space-conserving bid for weak hands? Balanced non-minimum is a good option (similarly 1♥-2♠-2NT if you use 2♠ as your GF raise over 1♥).

Here it is quite common to use “natural” rebids, ie new 4+ suits at the 3-level, and still call it Jacoby. Oswald would be spinning in his grave if he knew how often his name is taken in vain. (Or pronounced “Jacobi” as in Derek, which is standard around here).

Vampyr, on 2020-June-05, 21:26, said:

There are two reasons.

The first is that 1S-2N is frequently played as invitational plus, not game forcing (and 1S-3S is played as a mixed raise). (I play 1H-2S as the invitational+ raise in hearts.)

The second is that, when you have a minimum, if there's a slam, it's partner who will need to know information from you to judge, not the other way around, so it's helpful for partner to be able to relay at that point (even though your hand will be declaring), and that requires space.

FYI, our responses to 1S-2N are (for 1H-2S, adjust down a step):

3C - almost any min (see 4S)
3D - non-min, no shortness
3H - non-min, club shortness
3S - non-min, diamond shortness
3N - non-min, heart shortness
4C/D/H - 5+/5+, concentration of values
4S - min, 6(322) or 7222.

After the 3C response:
3D - asks for shortness, symmetric 3H/S/N responses, 4C/D/H deny shortness and are Italian cues.
3H - re-invite (this could be improved- but in a Precision context there isn't much point)
3S - drop dead, but opener expected to raise with a minimum with a 6+ card suit and shortness (b/c you should always accept a limit raise with a 6 card suit)
3N - suggestion to play
4C/D/H - maxi-splinter (too strong to splinter to start with)
4S - to play

I can see your point that if you are including invitational hands in your 2M+1 bids it is necessary to show the weak hands at a low level to give responser room to still explore. When that is not necessary, I have found that showing the stronger hand at a low level works well. YMMV

Vampyr, on 2020-June-06, 01:57, said:

Even if you don't include invitational hands there are merits to this scheme of bidding low with minimums. There are two goals here usually:
- don't reveal opener's shape if responder has an unexciting minimum GF also, that won't be greatly improved by any particular shortness, to make it harder for the defense
- leave max room if responder is strong enough to want to relay out shape anyway. If you use a higher bid for this, you can't relay out quite as many features, you can't distinguish say singletons from voids (which can be useful in my view) or other stuff you might care to design your system to query.

OTOH, when you have a balanced hand with extras, your suggestion for the cheapest bid, typically you don't need as much room, as you are bidding slams based on overall power and can just cue bid, maybe with some serious/non-serious steps to also define responder's strength range. IMO there is plenty of room to do that over say a 1M-2nt-3h! step showing this sort of hand.

Stephen Tu, on 2020-June-06, 02:27, said:

This is food for thought for sure; but naturally one doesn’t just change methods willy-nilly. One changes when a common hand type cannot be sensibly bid. I have not found this, although my partners might say that “sensibly bid” is an impossibility where I am concerned.

We have a separate bid for raises with a void, so that takes a little of the pressure off.

Vampyr, on 2020-June-06, 02:55, said:

I'm talking about finding out if opener has a void and a minimum (and only if responder cares), not responder showing a void spl raise. Responder's shape showing bids don't take any pressure off needing room to query declarer's shape when responder is balanced. If you are bidding higher and reserving first step for extras balanced (which I argue you don't really need quite that much room over), then either you can't relay out quite as many features, or you can't distinguish opener's mins vs maxes with shortness cleanly, or you tend to reveal opener's shape unnecessarily when responder isn't interested in slam opposite a min.

Zelandakh, on 2020-June-05, 18:25, said:

Around here almost everyone now opens minors that way and most will just tell you crossly "5 card majors".
The better informed call it "4 card diamonds", but then they will offer that as the explanation of an 1♣ opening too.

Vampyr, on 2020-June-06, 01:57, said:

The real point here is that you need to codify the structure so that Opener can show shape (shortages) and also be able to split the range up. Indeed Opener's range at this point is so wide that you really need to be splitting it up into at last 4 or 5 steps to be able to bid with any accuracy. To this end, there is a strong suggestion that the ideal follow-up to Opener showing shape (shortage) immediately would be for the next step to ask if extras are held. In combination with Serious/Frivolous 3NT or similar, this would then achieve the desired result. In this case, going shape->min/max or min/max->shape essentially gets you to the same point, so the question becomes which approach offers less to the defence when slam is not there. Experts (and me also) increasingly seem to think that strength first offers better chances to keep the defence in the dark and this as much as the desire to include the limit range inside the response has driven the move away from more traditional Jacoby structures.

There is one final approach that combines the two ideas together, as given by me earlier. The concept here is that Responder will almost always find it desirable to know the nature of Opener's hand (shapely vs semi-balanced) and whether extras are held, and that shapely hands require more bidding space so splitting them down to the first two bidding steps makes sense. If you go through the bidding sequences you can see that this approach achieves a similar level of packing as the more common ones. The downside is that Opener gives away slightly more information than the "first step = any min" approach with a minimum hand. The upside is that Responder will have to relay much less often at the second call.

Is the approach better? I don't know. I like it and feel that it leaks less information on average without forcing any wild leaps that shut down slam investigations. But the truth is that as long as you are playing a scheme that allows Opener to show relevant shape features and splits the strength range up enough, the precise codification is not going to make or break your auction, so play what feels natural and fits with the rest of your system.

Vampyr, on 2020-June-05, 21:26, said:

It depends on how the auction continues.

If you use one bid (3♣) for all the minimum hands, you have 4♥, 4♦, 4♣, 3NT, 3♠, 3♥ and 3♦ to describe the non-minimum hands. That is 1 bid versus 7. After 3♣, responder has 7 bids left to describe his hand, except that the GF 2NT response is not really meant to describe the hand. It pretty much functions as an asking bid, while setting the trump suit. So, if the auction continues with an asking relay of 3♦, opener now has 4♥, 4♦, 4♣, 3NT, 3♠ and 3♥ available. That is only 6 bids for the minimum hands, where he had 7 for the non-minimum hands.

If responder is relaying, after 3♣ opener will be able to show 13 hand types without going past 4♥ with the 6 bids that he has available. With a relaying responder, opener is able to show 21 hand types with the other 7 bids, without getting past 4♥.

So, while it may be true that 3♣ leaves more room than 3♦ or 3♥, in a relay structure it actually leaves precisely as much room as 3♦ and 3♥ leave together (or as 3♥ and all higher bids leave together). That means that the bids of 3♠ and higher can be used to describe even more hand types.

Using 3♣ to show a minimum is simple. I do not think that it is the optimal way to construct a scheme. However, the idea that it gives the minimum hands more bidding room than the other hands with extra values is simply not true.

Rik

Trinidad, on 2020-June-06, 10:11, said:

No one ever argued that it "gives minimum hands more bidding room than non-min hands". The argument is that if you are going to have a shape amorphous bid (for concealment when min responder isn't interested), it's best to have it as low as possible so that you have max room to relay when responder *is* interested. Now if you want to have opener show shape period, you can definitely show it more precisely not having a 3c min step, but at the cost of more revealing auctions more often.

In a relay type continuation, this gives an extra initial descriptive call for opener for the stronger hands (which is what you want, since you will have slam ambitions more often) as you noted. It also preserves more room for the min hands than using some higher bid for min hands which is what Vampyr apparently wanted, along with using the cheapest step for extras balanced which in my view is much less in need of the bidding room.

In my structure over the 3c min, responder can either sign off, relay with 3d or show extras with shape his own (too strong for immediate splinter).

I’ve played many versions of J2N, always gf. I am a strong believer in the notion that opener’s duty is to limit his general interest or lack of interest in slam asap. Note that, unlike say a 1N opening (where opener’s hand is narrowly constrained while responder’s is unlimited), in a J2N auction, both hands are, effectively, unlimited, especially on the upside.

When opener is strong, he can afford to consume a little bidding space, since the combined assets mean that, if responder doesn’t show a minimum, there is some high-level safety.

When responder is very strong, again there is some degree of high-level safety such that consuming a little space for opener to show a minimum is not damaging. So when opener is strong or when responder is strong, the choice of conserving or spending, reasonably, bidding space for opener’s minimum is pretty much a wash.

However, the most important hands are those where opener has a minimum and responder has extras but is not ‘very’ strong. Now both slam chances and the high-level safety needed to be able to probe beyond game are important and caN be maximized by conserving bidding space

IMO, this is the critical reason most J2N methods use the first step to describe a ‘minimum’. In my preferred methods (either of two complex methods) we use 4M to announce a hand that we’d almost passed, and 3C to say: minimum but not embarrassed by my opening. Just about any 12 count with 3 controls would be too strong for 4M, but we open virtually all 11 counts and some 10 counts.

When either or both players have lots of stuff, bidding space is not usually critical. It is when slam is not on power but on good meshes that’s one needs maximal space. Hence 1st step limits opener’s hand

I also agree with Stephen that there is no useful purpose served by havin* opener describe shape when slam is out of the picture. Doing so makes defending far easier than we want it to be.

Stephen Tu, on 2020-June-06, 11:20, said:

Well, I was replying to:

Vampyr, on 2020-June-05, 21:26, said:

I may have misunderstood, but I read Vampyr's post as:

• 3♣ is the most space conserving bid
  
• It is awful to reserve all that space that the 3♣ bid gives for the minimum hands

That statement does indeed not claim that the minimum hands get "more bidding room than non-min hands", but it does claim that it gets too much room. I thought it might be good to put that in some perspective.

I agree with your reasons why putting the minimum hands in 3♣ is good: to limit the hand, without leaking any other information.

Rik

Trinidad, on 2020-June-06, 12:53, said:

I am finding people’s comments on this thread very persuasive.