[blackshoe]

spotlight7, on 2019-June-11, 22:12, said:

Bridge World suggested "any three bids at the one level including

"pass in competition after opening" counted to be able to start xyz.

Quote

XYZ
In a partnership auction, after three suit bids at the one-level: (a) a rebid of two clubs by responder as a marionette to two diamonds (opener temporarily acts as though responder would pass two diamonds), after which responder may pass or make a game-invitational bid in any strain; (b) a rebid of two diamonds by responder as an artificial game-force; © a rebid of three clubs by responder as weak

-- The Bridge World Dictionary.

[ArtK78]

blackshoe, on 2019-June-21, 14:27, said:

My basic understanding of XYZ is that it applies when Z is a suit. AFAIK that is the original definition. I do understand that more recently some players have conflated XYZ and the convention I have seen called "modified 2-way Stayman" (MTWS), but that doesn't change my understanding that the two are different. They are similar in that in both methods 2!C asks partner to bid 2!D, after which the 2!C bidder will either pass or make an invitational bid. They are (significantly, IMO) different in that in XYZ, 2!C is a marionette, which means that opener can bid something other than 2!D with a suitable hand, but in MTWS 2!C is a puppet; opener must bid 2!D.

It may very well be true that the "original" definition of XYZ is that it applied to three suit bids at the one level. That is very restrictive, as there are very few auctions that begin with three one-level suit bids.

Adding 1NT as a possible "Z" bid increases the number of auctions where XYZ applies. And this is quite useful, as the XYZ structure is very good.

As for the 2♣ bid being a marionette rather than a puppet, that should only be true if opener CANNOT STAND a pass of 2♦. For example:

1♣ - 1♥

1♠ - 2♣

Opener holds:

AKxx Qxx -- KJxxxx

Opener should bid 2♥ just in case responder was planning on passing the "forced" 2♦ rebid.

Opener holds:

QJxxx Ax -- KQJxxx

Opener should bid 2♠ for similar reasons (besides just to describe his hand accurately).

[blackshoe]

Yeah, it's restrictive. So what? Does saying that XYZ only covers auctions where Z is a suit prevent you from playing "modified two-way stayman" which has almost exactly the same form but applies only when Z is 1NT?

I suppose it doesn't matter in the long run what you call it, since you can't just reply "XYZ" to a request for information when you alert one of the initiating bids.

[pescetom]

blackshoe, on 2019-October-23, 21:25, said:

Yeah, it's restrictive. So what? Does saying that XYZ only covers auctions where Z is a suit prevent you from playing "modified two-way stayman" which has almost exactly the same form but applies only when Z is 1NT?

It seems confusing to me to give two different names to what is now essentially a single convention applicable to two different situations. And if we really had to then I think XYN would be a heck of a lot more immediate and intuitive than "modified two-way stayman".

[mycroft]

I would phrase it the other way - XYZ was people realizing that their 2-way checkback system works well even when opener's rebid isn't 1NT.

But that's all semantics. YAreason why "convention name is not full disclosure" and "when you agree to play a convention, you have to go to the trouble of checking some things out".
(another good one is "what's XYZ-2NT vs XYZ-2♣-2♦-2NT? (potentially vs XYZ-2♣-2♦-3♣?)"

And I agree with Art (except I was only a fool for 10 years or so). Never going back.

[pescetom]

mycroft, on 2019-October-24, 11:13, said:

I would phrase it the other way - XYZ was people realizing that their 2-way checkback system works well even when opener's rebid isn't 1NT.

But that's all semantics.

"That which we call a rose by any other name would smell as sweet”, as someone said. Although one partner of mine argues that this convention would have more success if it was called ABC.

mycroft, on 2019-October-24, 11:13, said:

(another good one is "what's XYZ-2NT vs XYZ-2♣-2♦-2NT? (potentially vs XYZ-2♣-2♦-3♣?)"

All clear to us:
XYZ-2NT is a puppet to 3♣, either weak with desire to play clubs or 2-suited with slam interest
XYZ-2♣-2♦-2NT is invitational to 3NT
XYZ-2♣-2♦-3♣ is invitational with Y and clubs.

[mycroft]

That's one standard. And it's a good one.

There's another standard (which I play with my regular regular partner).

It is not good to have one partner think they're playing one way and one think the other!

That's why "check things out".

[pescetom]

Quite right of course.

More things to check out:
XYZ 2♣ 2♦ 3NT
XYZ 2NT 3♣ 3NT