[mgoetze]

A quick introduction for those unfamiliar: Zirconia is a convention devised by fellow poster Adam Meyerson awm wherein 1♥-1♠-2♦ shows 3 spades and 1♥-1♠-1NT shows 4+ diamonds or 2=5=3=3 shape. The purpose of the present post is to discuss followups to these bids.

1. What is 1♥-1♠; 2♦-3m?

In his notes which he graciously shared with me, Victor Chubukov (karlson) has these as natural, INV+, confirming a 5-3 spade fit. That does make a lot of sense, especially for slam exploration, buy my partner was quite disappointed to learn that he would have to play a 4-3 spade fit when he had 4 shoddy spades and a nice 6-card minor. We ended up agreeing that with an invitational 4♠6m hand he should jump shift, and then opener with 4 spades should make sure to bid 1♥-3m-3♠ en passant when accepting, but the question remains whether it would be better to have 3m available as a weak takeout for below-invitational strength hands.

2. How does opener checkback for a fit after 1♥-1♠; 2♦-2M?

Does he simply bid 2NT/3NT and hope responder will correct? What if opener wants to play 3NT even if there is a 5-3 fit? What if opener has game or slam interest only with a fit?

3. How to continue after 1♥-1♠; 1NT?

Adam in his original writeup suggests 2♣ as 4th suit invitational, with 2NT+ as natural and game-forcing. Victor suggests 2♣ as a near-puppet (opener bidding 2♦ unless he has 2=5=3=3), showing either a weak takeout to diamonds/spades/clubs or an invite (shown by bidding hearts or 2NT), with 2♦ as an ART GF. The latter seems more attractive to me, but perhaps that is because it is closely related to methods I already know well whereas 4th suit invitational is foreign to me. I'm not even sure whether I always have to jump with a maximum when responding to 2♣ ART INV. Perhaps someone can expound on the workings and advantages of that method?

[awm]

Often I play some method that limits the opening and makes #2 moot (i.e. strong club, or Zirconia/Gazilli). Otherwise I'd play that opener bids out his shape when holding extras (so 3m is like 3514, 2nt is like 18-19 bal, etc). I think the way to think about #2 is that opener has shown 8 cards of his hand and responder has shown four, so opener should just pattern out.

For #3, the way I play 4th suit invitational is that opener rebids in steps. So opener's 2♦ rebid is very min, 2♥ is medium, and higher is GF and sort of natural. The main advantage of this is letting us out in 2-red on declined invites a lot, which also means we can invite on a wider range of hands and helps with some tough hands like 15 opposite 10.

[wank]

am i getting confused? i thought you played 1nt as ♦ inc 2533 or strong a.k.a gazilli and 2♣ over that as the gazilli positive with anything else being a descriptive negative.

[mgoetze]

wank, on 2015-November-04, 05:24, said:

am i getting confused? i thought you played 1nt as ♦ inc 2533 or strong a.k.a gazilli and 2♣ over that as the gazilli positive with anything else being a descriptive negative.

That's a possible variation but not the basic convention. I think it's probably even better with Gazzilli but my partner and I aren't quite ready to work on all the followups after 1♥-1♠-1NT-2♣.

[mgoetze]

Should 1♥-1♠; 3m-3♠ promise 6 spades when playing Zirconia?