[hirowla]

Hi,

I was wondering how to handle slam exploration after Checkback style auctions (like 1♦ - 1♠ - 1NT - 2♣ - 2♠)? I have two major questions:

• How do you confirm the trump suit in those auctions? I'm thinking of this so you know whether you use Gerber or Keycard Blackwood to ask further?
  
• How do you handle it if you have less room to explore (like the Checkback starts at 2NT rather than 1NT)?
  
• What if you want to explore a minor suit rather than the major?

Any ideas?

Thanks,

Ian

[ahydra]

In your example auction, 2S would set spades as trumps if responder was to bid on with something like 4C (SPL) or 4NT (RKC).

With a two suiter (5-5) you can jump on the second round like 1D-1S; 1NT-3C. Not sure what the expert standard meaning of e.g. 1D-1S; 1NT-2C; 2S-3C is (NAT GF?). Going back to opener's first suit should be natural, but again I'm not sure whether that's just to play, INV, probe for 3NT, or SI.

After 1M-2m, we play 2NT as two-way (either 15-19 BAL or a slam try in either opener's or responder's suit), and if responder bids 3C checkback we show the slam try in responder's suit with a bid of 3oM. Similarly after 1S-2H; 2NT-3C we have 3H = heart slam try, 3S = spade slam try, 4x splinter for hearts. This is a weak NT, 5cM, 2/1 not GF system; of course things change a lot when you're playing strong NT.

Edit: Do consider playing XYZ (2C relay to 2D to show weak/INV, 2D GF checkback) rather than just regular checkback if you're not doing this already.

ahydra

[lycier]

You would better play XYZ and two way stayman,I suggest to play Modified two way stayman by Grant Baze.
If so, many bidding problems will be readily solved.

[Zelandakh]

 ahydra, on 2015-November-19, 05:51, said:

In your example auction, 2S would set spades as trumps if responder was to bid on with something like 4C (SPL) or 4NT (RKC).

Well yes but it would be nice not to have to lose so much bidding space on a slam hand!

 ahydra, on 2015-November-19, 05:51, said:

With a two suiter (5-5) you can jump on the second round like 1D-1S; 1NT-3C. Not sure what the expert standard meaning of e.g. 1D-1S; 1NT-2C; 2S-3C is (NAT GF?). Going back to opener's first suit should be natural, but again I'm not sure whether that's just to play, INV, probe for 3NT, or SI.

I am not sure there still is an expert standard for simple checkback as almost noone is still playing it. The way I learned it is that direct bids are invitational and going through NMF is GF. That said, natural GF is rather a small target here, basically 4(32)4 with slam interest, so I would consider switching this to artificial in an established partnership as a no-brainer. This is the obvious place to include a slammy hand with 5 spades.

 ahydra, on 2015-November-19, 05:51, said:

After 1M-2m, we play 2NT as two-way (either 15-19 BAL or a slam try in either opener's or responder's suit), and if responder bids 3C checkback we show the slam try in responder's suit with a bid of 3oM. Similarly after 1S-2H; 2NT-3C we have 3H = heart slam try, 3S = spade slam try, 4x splinter for hearts. This is a weak NT, 5cM, 2/1 not GF system; of course things change a lot when you're playing strong NT.

After a 2NT rebid, my suggestion for the OP would be to use transfers. There are many write-ups of this approach to be found on BBF.

 ahydra, on 2015-November-19, 05:51, said:

Edit: Do consider playing XYZ (2C relay to 2D to show weak/INV, 2D GF checkback) rather than just regular checkback if you're not doing this already.

Two-way Checkback (XYZ is similar but applies to a different auction type) is very much the modern solution and tends to simplify things considerably. That said, anyone who thinks such auctions cannot still become murky is fooling themselves. I can remember two of the strongest BBFers having difficulty in a 2WC auction a while back and if it can happen to them it can happen to anyone.

[ggwhiz]

I'm fond of Kantar 2♣ where the check back is always clubs regardless of the opening bid.

By definition it is invitational plus so any opener that would accept an invitation has room for fairly complex super accepts that show (almost) exact shape. Of course being Kantar his original write up is 40 pages and most people only play the first one and a bit.

If you still have a slam try opposite a non super accept you have to bid a new suit (can be an advanced cue) or jump in yours demanding a cue from partner unless they are REALLY ashamed of their opener.