[awm]

Suppose the opponents open 2♦ multi (weak two in a major, possibly with other strong options). In most defenses, an overcall of three of a minor is natural and shows a reasonable hand (like overcalling three of a minor when opponents open a weak two bid). If the auction has gone:

2♦ (multi) - 3♣ (or 3♦) natural - Pass - ???

How do you show a slam-interested raise of partner's minor? The normal method of "cue-bid the opponents' suit" is of course unavailable since the opponents' preempt did not specify a suit. Neither of the ACBL defenses discuss this at all (once again showing issues with the ACBL defenses).

[shyams]

Not an expert. Also, quite sure this was never in my system notes of any past partnership.


IMHO, playing a natural & forcing structure for advancer is best.

(2♦) 3♣ Pass
* 3♦, 3♥, 3♠ natural and forcing. May be a 4-card suit if advancer intended to show a good hand with fit for ♣ in subsequent bids.
* 3NT is to play. Overcaller can continue to bid on with slam aspirations.
* 4♣ natural invitational. You can define HCP/strength range based on what your partnership feels is acceptable for the 3♣ overcall.
* 4♥/4♠ to play, long suit. No interest in partner's minor.
* That leaves 4♦ which you can agree to be some conventional bid.


(2♦) 3♦ Pass
* 3♥, 3♠ natural and forcing. May be a 4-card suit if advancer intended to show a good hand with fit for ♦ in subsequent bids.
* 3NT is to play. Overcaller can continue to bid on with slam aspirations.
* 4♦ natural invitational. You can define HCP/strength range based on what your partnership feels is acceptable for the 3♦ overcall.
* 4♥/4♠ to play, long suit. No interest in partner's minor.
* Not sure if there is merit in keeping a natural meaning 4♣. Perhaps this can become the conventional bid with some specific purpose.

[mw64ahw]

The Multi vs. Multi on Chris Ryall's website uses a transfer approach 2♠/2N for the minors. You can use one of the steps as a GF and then on from that decide whether to SI or not. A direct 3♣/3♦ are down as preemptive although I guess you could use the combinations to communicate different opening values of overcall instead.

[mikeh]

The OP raises an interesting point to which I have answer other that a new suit advance is surely F1….but what does it show? And how, thereafter, does advancer show ‘more’ values?

As Op notes, the acbl defences are woefully deficient. Option 1 is much worse than option 3, but neither strike me as appropriate for a serious partnership.

However….we played 6 days of round robin and three days of KO in the still ongoing (ends today) Seniors here in BA. We had our acbl defences at hand….none of our opps had the slightest interest in them….every pair said that they ‘knew’ how to defend (not usually in those exact words) and iirc we opened 2D 3 times all week! And while a number of pairs had multi on their CV, I don’t recall anyone opening 2D against us…if they did we definitely didn’t compete.

We do use a version of option one if, over our 14-16 1N, an opp overcalls a multi 2D and that did come up once.

I’ve read the multi v multi defence and think it is definitely worth looking into. In an invitational online event sponsored by the Polish Bridge organization, a few years ago, our teammates employed it to devastating effect…an international pair played their 3=0 fit in slam as opposed to their, iirc, 6=5 fit. There was complete confusion as to who had which major in a rapidly escalating auction after 2D x.

[helene_t]

I would play a direct raise as forcing.

A bigger problem is how to show a stopper in one major. After 3cl we can use 3di to ask stoppers, then direct 3M shows length.

After 3di, 3he asks for a spade stopper. Now 3sp shows the spade stopper but also a hearts "fit" in case that was what advancer wanted.

After 3di, if advancer has a spade stopper but no ling major, he just has to take a view. Probably just 5d.

[nullve]

I prefer defences where the Multi 2♦ is treated like a Weak 2♦ unless Responder bids something. And if playing a standard Weak 2♦ defence against Multi 2♦, then obviously

(2♦*)-?:

* Multi

P: also with any hand that would overcall 3♦ in the OP system
(...)
3♣: NAT
...any: as if 2♦ were a Weak Two, including
...3♦ = cue
...3M = 5+ M, FG
3♦: ART
(...)

.