[antonylee]

I currently play a fairly classic XYZ in a classic 2/1 -- 2♣ forces 2♦ to play or INV, 2♦ GF, 2N forces 3♣ to play or shows one of the 5431s with 9 cards between opener's suit and responder's suit.

I am considering switching to a short-club (unbalanced diamond) approach and ultimately T-Walsh, as described in http://bridge.mgoetze.net/21twalsh.pdf (i.e. transfer completion = 11-13 bal <4M or 11-14 5♣3M unbal). Consider the auction 1♣-1♥!; 1♠!-... It seems easy enough to keep playing XYZ here; this is also what mgoetze's writeup suggests. But there are some subtleties...
(1) Over 2♣ (nominally a puppet to 2♦), it seems reasonable to play e.g. the relay breaks 2♥=3415 max, 2♠=3xx5 max... or something else?
(2a) Over 2♦, should opener tend to reveal a 5-card minor immediately if he doesn't have 4♥ or 3♠? It would seem that differentiating between e.g. 2353 and 2335 may be useful for slamming, and you're not really revealing more than standard bidders who will have opened either 1♣ or 1♦ (specifically, 3♣ doesn't reveal more as the standard 1♣-1♠; 1N-2♦!; 2N auction should be exactly 2335 (or possibly 2245), 3♦ would distinguish between 5=3 and 4=4 in the minors which standard bidders don't reveal)... or would you rather conceal as much as possible? (2b) Also, I guess the 5♣3M unbal hands can be shown with 3-level jumps over 2♦?
(3) The 2N->3♣ 5431 sequences mostly make sense when opener's longer minor is known; in a short-club approach, there isn't really a reason for responder to have a sequence to show e.g. 4135 but no way to show 4153. Should we keep them as is, or e.g. show 4315/4135/4351/4153, i.e. put all GF hands with 5♠ into 2♦ and be able to show club and diamond based hands equally well?

Note that (2a) and (3) (mostly) apply in any short-club approach, independently of whether one plays T-Walsh or not.

Any suggestions are appreciated and welcome

[wank]

over 2D gf cb, yes describe your hand as much as possible. if responder just wants to offer a choice of games, he can do that via 2C puppet then 3M/NT.

as for 2C, yes consider this a marionette rather than a puppet, i.e. you're expected to bid 2D unless you have extra shape, particularly unplayability in diamonds.

[fromageGB]

I am not a fan of XYZ nor a user, so my comments may be ignorant, but it seems to me that XYZ has been designed for natural majors rather than transfer majors. You have all that extra room, and I am sure you can do something better. Do you never want to play in responder's 5+ card minor when he has a minimum hand with a non-fitting 4 card major? How do you handle weak both majors 44xx or {54}xx?
Q1) Your relay breaks obviously kill the idea of playing in 2♦; your 2M breaks seems to achieve little given that by definition you are in game strength with no chance of slam. Maybe any break shows diamond shortage, if this is not included in your unbalanced diamond, so that an escape from 3NT can be made when responder has poor diamonds.
Q2) My feeling is that opener giving away info about minor length is not a good idea. Presumably if responder had a GF with a minor he could bid 1♥! followed by 3m.
Q3) Opener isn't going to have a 4135 or a 4315 or 4153 if you are playing unbalanced diamond.

[antonylee]

Re 1): The point is to avoid being dropped in 2D when responder has a weak hand and opener a hand just strong enough for game opposite a hand with shortness, but was otherwise intending to signoff in 2D opposite a balanced minimum. But perhaps I'm aiming for too small a spot here.
Re 3): These are responder's shapes.

[fromageGB]

antonylee, on 2019-November-17, 14:10, said:

Re 3): These are responder's shapes.

Sorry, I read it too quickly. 2NT responder rebid could be used for any GF {5431} but I think you may be running out of space. Assuming the 5 card suit is a major, for example, shown initially, and you then rebid a 4 card suit (3NT if clubs?) opener will not know what the short suit is. You will need to use 2♦ for some hands, and even then I don't think you can show the shape. More importantly, a 3NT contract being played by a hand with a known shortage tends to make the defence a little easy :-)

Perhaps this 2NT is not a good idea. If there is not a major fit, and if opener does not show a long suit, hide the singleton and just let NT be the default if not slam strength.

[antonylee]

A fairly classic scheme (in non T-walsh) is
1m-1M; 1N-2N!; 3♣! (forced) then...
- P: to play
- 3♦: 5M4m, low shortness
- 3♥: 5M4m, high shortness
- 3♠: 4M5m, low shortness
- 3N: 4M5m, high shortness
I'm not particularly attached it (although it's perfectly fine); my question was mostly how much to keep and how much to throw away when going to a short club, T-walsh approach. For example, your remark on hiding the singleton is certainly reasonable -- I missed the wrong-siding issue here.