[shnk]

2/1
1)
1♠ - 2NT
3♣ - ?
2NT is Jacoby, 3♣ shows shortness, what is 3♦ or 3♥ by responder?

2)
1♠ - 2♣
2♥ - 2♠
2♠ shows extras, how to define the three level bids by opener here?

[eagles123]

on 1 would have thought 3♦ or 3♥ were cue bids?

2 I'm not sure

Eagles

[Codo]

1. you have several ways,to define these bids. For me the first "cue", here 3 ♦ starts asking sequences, usualy whether this is a void or singleton, Kcs, etc. 3♥ shows a control, asking partner to define his hand further.
2. It depends on your system. For me 2 ♣ is gameforcing and 2 ♠ a real raise, 3 cards usually, never less.
In this framework, all bids show values to look for a slam.

[Fluffy]

1 is taken as cuebid by most, although best is to show strains in need of complement or something else.

2 the most useful thing is to pattern out showing your shape (2NT=5422, 3m = 5431, etc)

[PhilKing]

Auction 1:

Step one = RKCB with zoom (step 1 = void, step 2+ RKCB responses)
Step two = artificial try, invites cues
step 3/4 = own shortage

Auction 2:

It's important NOT to show anything whatsoever if you are minimum, since it will merely help the opponents. The solution as discussed in a recent thread is to play a variation on serious/non-serious, so 2NT shows any non-terrible minimum and 3♣+ show extras and pattern.

[aguahombre]

shnk, on 2013-June-30, 04:23, said:

2/1
2)
1♠ - 2♣
2♥ - 2♠
2♠ shows extras, how to define the three level bids by opener here?

PhilKing, on 2013-June-30, 11:18, said:

Auction 2:

It's important NOT to show anything whatsoever if you are minimum, since it will merely help the opponents. The solution as discussed in a recent thread is to play a variation on serious/non-serious, so 2NT shows any non-terrible minimum and 3♣+ show extras and pattern.

Agree with Phil's answer to your conditions. Disagree with the conditions. When the 2S rebid by Responder guarantees extras, Responder must do something more space-consuming to show a minimum 2/1 with Spade support while Opener is still unlimited and might like to use the available space. IMO, 2S should merely set trump and be non-commital about extras. Then 4S instead of 2S would be "picture", and 3S instead of 2S would be available as 4-card support, and a demand for control bidding.

[P_Marlowe]

#1 Cue - a good idea is to play the first cue as value showing, i.e. the cue showes king or ace
#2 2S showes add. values, hence you are investigating slam => suit bid on the 3 level are cues,
given that opener showed 54, you may agree that the cue in a new suit now showes shortness

With kind regards
Marlowe

PS: Using 2NT as a bid to limit openers hand is certainly a sensible idea.

[Zelandakh]

On auction 1, the meaning without discussion would be a control bid. A reasonable alternative if you believe in "support with support" is for these bids to show a good side suit, equivalent to bidding the suit and then supporting the major but showing the fourth trump. Another alternative is to play the first step as a slam try (Frivolous) and other steps as serious cues (and 3♠ now becomes a cue in the suit of the first step).

On auction 2, it seems best to use 2NT as a minimum (Frivolous). Whether to use higher bids for controls or patterning out is a matter of taste. My choice would be patterning out.