[Zelandakh]

 dave_beer, on 2016-April-02, 12:04, said:

doesn't want to rebid 2NT because there is no ♦ stopper

2NT shows a diamond stopper? I am not a 2/1 player but the material I have read suggests that Responder's 2NT rebid sometimes needs to be used as a temporising call and is therefore an easy choice with this hand type.

[dave_beer]

 kenberg, on 2016-April-02, 12:54, said:

So I am taking your comment here as supportive of my general view.

His thinking as that since the initial 2C bid could be quite short (2D and 2H would both be five card suits) that it is essential to get the five card length shown.

Agree with you and disagree with your partner. I think it is more important for 3♣ to show real length.

A hand that has a three-card ♣ suit and doesn't have three-card support can usually rebid 2NT but may have to rebid 2♠ as in the example I gave; one that has a two-card ♣ suit has to have three-card support (this can happen after 1♠ opening).

In both cases opener can now rebid 3♣ with 3-card support.

[dave_beer]

 Zelandakh, on 2016-April-02, 13:10, said:

2NT shows a diamond stopper? I am not a 2/1 player but the material I have read suggests that Responder's 2NT rebid sometimes needs to be used as a temporising call and is therefore an easy choice with this hand type.

It is better to have a full or partial stopper but sometimes you have no choice. I think it is foolish to rebid 2NT, have partner raise to 3NT with ♦Kx and go down when some other bid would have allowed partner to bid NT first and right-side it.

[Stephen Tu]

If you want the 2 level preference to show 3, the rebid of the 2/1 suit to show 6, and the 2nt bid to show a stopper (which I think it ought to, because of siding considerations plus the fact that partner would have to make a lot of very unnatural bids if he has to cater to you not having a 4th suit stopper; I think most 2/1 players expect a stopper here), the most obvious thing to do is to have 4th suit (1s-2c-2h-3d) still be artificial and deny a stop, and show this problem hand. It's pretty rare to have a fit in the 4th suit and want to play there, and even then this can be found by responder bidding 2nt when holding clubs & diamonds, and opener rebidding 3d when holding 5-4-4-0.

I think most people who claim "we are in 2/1 auction, don't need 4th suit artificial, everything can be natural" haven't really examined all the possibilities carefully.

[dirtbag]

the 2♣response may well be artificial, it is the cheapest 2/1 call, with the responder knowing the hand is playing in ♥ looking for more information about the opener's hand while telling nothing useful to the defense. all this talk about a double fit is sayc folly. the 2♣ call usually has a ♣suit attached to it but some game going hands with slam interest could bid 2♣/1♥ with fewer than 4 ♣.

bid slowly to show strength is the 2/1 mantra, for example 1♥/2♣/2nt is a stronger opening hand than 1/♥/2♣/3nt

[kenberg]

 dirtbag, on 2016-April-02, 18:46, said:

bid slowly to show strength is the 2/1 mantra, for example 1♥/2♣/2nt is a stronger opening hand than 1/♥/2♣/3nt

As I play it, the 2NT rebid is either weaker than a 1NT opening or else stronger than a 1NT opening. So the auction 1H-2C-2NT-3NT-4NT is very possible. It shows 18 or 19. I regard this as reasonably standard in 2/1 but as we have already seen, tastes vary.

After 1H-2C, not a lot is known about the responding hand and 2NT leaves room. I think it would be a mistake to set things up so that opener had to rebid 3NT to show a minimum. The auction 1H-2C-2NT-3D could be very useful, even if opener is a minimum, for example. Opener can then bid 3NT with some hands, meaning if you want to go on you are on your own, or he could make an encouraging 3S call.

[kenberg]

 Stephen Tu, on 2016-April-02, 18:23, said:

I think most people who claim "we are in 2/1 auction, don't need 4th suit artificial, everything can be natural" haven't really examined all the possibilities carefully.

Yes. The fourth suit can be "I lack a better bid" . When holding a stopper, especially with Kxx rather than Axx, clearly NT is a more descriptive bid. Or, on occasion, the fourth suit might be on Ax where, after pard perhaps then bids NT you intend to pull to his suit, showing a fit, a control, and a slam try.

[Zelandakh]

 kenberg, on 2016-April-02, 19:14, said:

Yes. The fourth suit can be "I lack a better bid".

There are different styles and all of them have their merits (and issues). One sensible approach is for the cheaper of 2NT and the 4th suit to be the temporising bid and the other to be natural. That has the advantage of Responder always having a cheap way of relaying but the disadvantage of wrong-siding sometimes in comparison with the 4th suit being artificial. In auctions where 2NT does not show a stopper, 3 of the 4th suit is then typically used as a check on the way to 3NT.