[dae]

The opponents were bidding ,not an established partnership, no bidding by our side... Opening -1S, 2 H,3H 3S, pass... A trick or two was played and the 2 H bidder asked for a redeal(she is learning 2/1 system and asked if H were agreed trump suit, said that she was bidding a control by biddindg 3 s...
she held the AQ10 of spades.. Request was refused,,
The question is , is H the agreed trump suit? Her partner assumed she was raising the S suit, and passed..... (Which -in 2/1 - the 2 H was GF.) ( I had 5 S in my hand-there was not a slam, as she had thought.)

[mgoetze]

I think it is reasonable to play 1♠-2♥; 3♥-3♠ as either showing a double fit or the beginning of a cuebidding sequence, it's something that needs to be agreed and I doubt there is a consensus standard interpretation. Obviously, passing 3♠ is not an option in either case.

[BillPatch]

We are several tricks into the play and the final contract is 3♠. If one cannot figure out the trump suit from that info, may I suggest another game.

[rmnka447]

I agree that whether 3 ♠ shows a double fit or is a cue bid is a matter of partnership agreement.

Personally, I think showing the double fit is much more important.

One thing to remember is that double fit hands have the potential to take a lot of tricks. They are the kind of hands that can very easily yield slam on not a great deal of high card points. They do so because whoever is declarer may be able to discard potential losers on dummy's long suit tricks. If you have solid suits and controls in the side suits, 12 tricks are often available.

There have been a couple threads recently where responder held a big fit for opener's suit and held a good 5+ side suit. There was some really cogent arguments made that showing the side suit was more important than splintering or simply making a forcing raise. The rationale was that identifying the potential source of additional tricks to opener was important to potentially finding the right spot -- game vs. slam.

One final thought, if 3 ♠ in the stated auction is a cue bid, then how do you ever get to a ♠ contract? Suppose responder has something like

♠ Kxxx
♥ AQJxx
♦ xx
♣ Ax

If after 1 ♠ - 2 ♥ - 3 ♥-?, you are committed to playing in ♥s, then you may end up playing in an 8 card fit instead of your known 9 card fit.

While it is normal to treat new suit bids after suit agreement as cues, I think the one exception should be to reveal the 2 suited fit. So, 3 ♠ would show the double fit and be the only new suit bid not a cue.

BTW, to show the power of double fits, give opener something like

♠ AQxxx
♥ Kxx
♦ Axx
♣ xx

and 6 in a major is almost lay down with the above responding hand on 27 total HCP and no unusual distribution.

[Jinksy]

I don't have a strong view on whether it's better as cue or fit, but I don't think that argument's very convincing. Double fits are nice, but if you've got enough controls for slam, you only need one long suit and some matching honours in P's hand. Revise the hands above to these:

♠ Kx
♥ AQJxx
♦ xxx
♣ Axx

♠ AQJxx
♥ Kxx
♦ Axx
♣ xx

And slam looks nearly as good. Looking at just opener's hand (south), you'd much rather P had virtually any king-headed holding in Ss than any number of Xes. But with you both holding relative minimums, slam will be tougher to find if responder can't cue. Suppose you bid 1♠ 2♥ / 3♥ 4♣* / 4♦** 4♥

* Bypassing serious 3N
** Last train or D cue as you prefer (it makes life easier here if it's a cue, but reverse the minors in both hands and you get a similar problem either way)

Opener can bid on, but I'd expect responder to have bid similarly with

♠ xx
♥ AQJxx
♦ xxx
♣ AKx

And now you don't have five-level safety.

Also on the original two hands depending on methods, there's reasonable chance responder would just start with a 2N bid. If opener will be able to show a balanced hand and then cue Hs you can find out about the K anyway, so it looks like you'd only really lose out when opener has the stiff K and shows it as shortage (and you'd gain in various competitive auctions).

[kenrexford]

I strongly prefer hearts set. Solves the problem of, say, Ax AKQxx xxx xxx.

I solve the problem of Kxxx AQJxx xx Ax in a strange way...responding 2C. I hope for 2D, which allows a 2S raise, lower cues, etc. If partner bids 2H, I still set spades as trumps for the low cues. If partner raises clubs, I dislike the auction, but I set spades as trumps and manage. If partner splinters, I am well placed. Responder doing this means that Responder often makes decisionbids.

An alternative, for those like me who dislike Jacoby 2NT,is 2NT as GF with hearts and spades.

[TWO4BRIDGE]

1S - 2H
3H - 3S

In 2/1 GF, this is the exception to double-fit auctions .

Hearts are the established trump suit, and 3S = a cue-bid .

[BillPatch]

TWO4BRIDGE, on 2015-September-07, 16:37, said:

1S - 2H
3H - 3S

In 2/1 GF, this is the exception to double-fit auctions .

Hearts are the established trump suit, and 3S = a cue-bid .

In one version of 2/1 GF(presumably Max Hardy's)this is true. In Bridge World Standard, which is consensus based on polling, this is not true. A purist might say that BWS, which provides that 2/1 is not a gf with a minor rebid and that 2 clubs over one diamond does not promise more than a rebid, is not 2/1 GF. But unless someone else comes out with a cleaner or more recent poll, I think the BWS polls are our best indication of how the general population of 2/1 GFers treat this auction and should be in BBO's and Bridge Winner's default systems. Comments?

[jdonn]

I definitely think 3♠ should be a control bid agreeing hearts, but most people probably feel it should be natural and that is what I would assume undiscussed.

[blackshoe]

I think it's a bad idea to assume the meaning of any undiscussed bid is artificial. The corollary to this is that if you think a particular bid should be assigned an artificial meaning, you should discuss it with your partner, preferably before it comes up at the table. Most people don't do that.

[mgoetze]

blackshoe, on 2015-September-09, 19:04, said:

I think it's a bad idea to assume the meaning of any undiscussed bid is artificial. The corollary to this is that if you think a particular bid should be assigned an artificial meaning, you should discuss it with your partner, preferably before it comes up at the table. Most people don't do that.

RHO opens a spade and I overcall 2♥. LHO raises to 2♠. Well, we've never discussed this sequence so everything must be natural. Partner jumps to 4♠, RHO passes and I... pass? Yeah, sounds sensible.

[Vampyr]

mgoetze, on 2015-September-09, 20:12, said:

RHO opens a spade and I overcall 2♥. LHO raises to 2♠. Well, we've never discussed this sequence so everything must be natural. Partner jumps to 4♠, RHO passes and I... pass? Yeah, sounds sensible.

This is silly.

[mgoetze]

Vampyr, on 2015-September-09, 21:21, said:

This is silly.

That's the point.

[Vampyr]

mgoetze, on 2015-September-10, 03:44, said:

That's the point.

Well, your post is silly, but the idea of assuming that an undiscussed bid is not artificial is not.

[mgoetze]

Vampyr, on 2015-September-10, 11:53, said:

Well, your post is silly, but the idea of assuming that an undiscussed bid is not artificial is not.

Care to explain the difference?

By the way, blackshoe did not just espouse the idea of assuming undiscussed bids are not artificial - he disparaged all alternative approaches. Whereas I believe that "undiscussed bids are assumed artificial when it makes sense for them to be" is also a perfectly good partnership agreement.