[el mister]

This is quite a basic question - is there a standard use for the 3 level in 2/1 game forcing sequences? Had one or two misunderstandings with pard about what is a cue and what is just a suit-showing bid.

Say the uncontested auction 1♠-2♣-3♣ back to me. Holding something like ♠x♥Jxx♦AKxx♣AQJxx

If I now bid 3♦, should that show 4 diamonds, describing my hand some more, or could it be taken as a control-showing bid?

Or the major suit auction 1♥-2♣-2♦-2♥. Shall we just start cue-bidding forthwith at the 3 level?

[helene_t]

After a minor fit has been found, the 3-level is primarily used for finding out if we can play 3NT. So 3♦ here doesn't show four diamonds, nor does it strictly show a diamond control although it will usually have one - QJTx is possible. It shows values in diamonds.

After we have found a major suit fit it is a question of agreement whether opener patterns out or show controls. You could play patterning until 3M and control bids thereafter. By the way, for some 2♥ doesn't guarantee 3-card support, in which case you would still be looking for 3NT.

[kenrexford]

As to major fits, as stated, there's two schools.

The pattern out approach has opener make one more pattern bid and then cuebid starts. I personally do this if playing canapé.

The other school starts cue bidding immediately, which is what I do with 2/1 GF.

There are many discussions about this on bbf, often debated with some passion. My personal take is that pattern first works best when Opener is limited (canapé or Precision, for example) while cue bidding works better when opener is unlimited (e.g, 2/1, K-S, or standard). The reason for the difference has to do with needs. The limited auction has information advantage, which allows fine tuning distribution, with space loss from that approach being minimized. With unlimited auctions, you need more room to unwind things, and cuebid sequences are more useful space friendly (even bypasses exchange information).

There's also some alteralternative approaches, which are asking bid sequences. These also seem to work best in limited auctions. Consider these the artificial science alternative to the pattern option. I have used this in some canapé systems, but usually in the context of an unusual response structure, where opener becomes a puppet rather quickly. I suppose spiral scans fit into this category, as well.

[Zelandakh]

After a minor fit the new suit is either checking for 3NT or an advance cue. Partner assumes the former and the later auction will make it clear if it was the latter. In my system (not 2/1) I have some sequences where agreeing the minor guarantees slam interest and then cues at the 3 level become more appealing. In fact I also use the first step (3♦ or 3♥) in these sequences as Frivolous, effectively a decline of the slam try, which makes for an easy stop in 3NT sometimes when slam is not on the cards but does not waste space when partner really has a full slam drive.

Over a major I think patterning out is regarded as the standard but going straight to cues is a viable alternative. An interesting amendment to the latter would be to use the first step as Frivolous, similarly to the method described in the previous paragraph, and subsequent steps as Serious cues. 2NT here could be used to substitute for a cue in the Frivolous suit. As helene points out though, you do have to be very careful here that both partners are on the same wavelength about whether a real fit has actually been shown.

[kenrexford]

As a related aside, after a minor fit and a call that is a probe/advance Q, the ideal agreement Imo is for the advance Q to maintain consistent meaning type. If the probe shows, the advance Q shows. If the probe asks, the advance cue is denial. The meaning is retroactively understood, but the next calls make more sense if the type will be consistent. You can revert away from the denial to Italian with no need to stay denial, but the initial ambiguous call should be consistent type. This also keeps in mind the situation where the purpose changes, such as where the probe is made with mild interest that grows up if 3NT was rejected.

[Zelandakh]

Agree with Ken's last point 100% and therefore use asks here when also playing denial cues. That also carries across into related auctions such as when a 2-suiter has been shown by the opponents.

[P_Marlowe]

No idea what standard is, but

If your first cue is always showing honors, instead of being blurry, i.e.
it could be either a honor or a shortage based cue, then the meaning of
3 of suit after a minor / major suit fit got discovered is basically identical,
and it is also covering to some extend the pattern out, since if you pattern out,
do you really show xxx in new suit?

Of course if your focus is finding the best game, you may show QJx in a side
suit after a minor suit fit got discovered, and wont show this after a major
suit fit got discovered.

With kind regards
Marlowe