[Liversidge]

My partner wants to learn about splinters. I was thinking about introducing him to the Jacoby 2NT first and then move on to the principles of splinters and wasted values.
Are there any benefits in the Jacoby 2NT when playing Acol and 4 card majors, other than in those cases where partner has a splinter? I can show a 12+ HCP hand with 4 card support for partner's major by bidding a 4 card second suit or by lying in a minor, and then bidding game in the major, to distinguish it from a weak 7 loser hand with 5+ card support where I would jump straight to game in partner's major.
I have tried and failed (so far) to construct any pairs of hands where the Jacoby 2NT finds a better contract than could be arrived at using natural bids.

[wank]

responding in a new suit then jumping to game is called a delayed game raise (DGR)

1) it should be obvious that playing a DGR as 12+ is unworkable - opener would never know when to advance if you can have 12 or 18. it should be a minimum game force, i.e. 12-bad 15.
2) DGRs eat up lots of space meaning it becomes difficult and dangerous (have to bid to 5 level) to check you have all the suits controlled (cuebid) if you decide you want to investigate slam
3) opener/opps doesn't always make it easy. for example, let's say you bid 1H-1S planning to make a DGR, but opener jumps to 3D. now the problem is you've never shown your strength or long trump and as 4H now is just a sign-off, it will become awkward to get these across, particularly the 4th trump. you should still get to slam ok, just based on points, but you'll find it difficult to successfully bid grand slams.

[Liversidge]

Thanks. Helps a lot. I will work up some examples to demonstrate the points you have made.

[The_Badger]

Bidding is all about making space to describe hands. Acol may be a neat system, but some of the ideas it promotes have been well and truly superseded with a move towards five card major-based systems, such as 2/1.

If you add a Jacoby 2NT into your artillery, then you will have to tweak what the former bids for Delayed Game Raises mean. That in itself may have to be covered by Laws and Rulings, I assume.

The principle idea of bidding constructively is that a bid is uniquely descriptive (within certain parameters) and no other bid can duplicate its meaning. In essence, every bid has its own meaning to show a certain type of hand.

Therefore, what you say about DGRs and a Jacoby 2NT bid prove that duplication will take place.

[Cyberyeti]

Quite a number of people (certainly around here) play 2N as inv or better rather than GF, meaning the raise to 3 is now preemptive, and DGR is usually 3 card support with the occasional 4 cards in partner's suit (522).

[P_Marlowe]

Hi,

your topic is related to the important topic, who is in a given bidding sequence,
the captain in the partnership, look for "captaincy", e.g. precision is all about
captaincy.
A short defnition: The captain is the one, who knows enough, to make a final decision.

If you make a Jacoby 2NT bid, you say, you are the captain, you ask partner to describe
this hand, so that it allowes you to decide, if the hands have a valid potential to go
looking for slam.

If you make a splinter bid, you are basically making partner the captain, i.e. you ask
partner to decide, if the hands have a valid potential to go looking for slam.

If you make a DGR, you also make partner the captain, he has to decide, if he should move
on. Since there is no room between the game raise bid and the game level, the DGR should be
pretty well defined.
This is also true for splinter, the splinter ranges can get wider, if there are more bids
avaible between the splinter bid and the game bid.

Using this idea should make it easier for you to construct hands, which route makes it easier
to decide SI Yes / No

In terms of simplicity, I would start with splinter, but it may well be worth your time, to
discuss, who is captain first.
From a frequency point Jacoby 2NT will be better, but adding splinter to a Acol Set will require
nearly no add. brain power, what replaces what.

The Captain is also showing up, when you make a overcall, or when you make a preempt
If you make a preempt, do you bid again? Usually: No, partner is captain.
And I would highly recommend, if you discussed, who is captain, respect the decision of the
captain, even if it backfires sometimes.

With kind regards
Marlowe

[helene_t]

Stephen's list is excellent, I would just add two issues:

Consider
1♥-(p)-2♣-(2♠)
p-(4♠)-?

Having to make a 5-level decision without having shown your 4-card support is awkward. Better to show your support and then, if you haven't anything to add, let partner make the decision.

Another issue is that the delayed game raise should show a concentration of values along with your support. If you respond 2♣ and partner has the king of clubs he should be able to upgrade his hand. Suppose you have
Kxx-AKxxx-Jxx-Qx
and partner opens 1♥. Bidding a minor now will be misleading. Bidding spades as slightly better but if partner has four spades it may be difficult to convince him not to correct a heart contract to spades.

More generally, bidding suits you don't have is a source of confusion. If the message you want to tell is that you have support, then show support.

And there is no reason not to play Jacoby 2NT. It's not a difficult convention, and it's not like you need 2NT for anything else.