Caitlynne, on 2016-July-29, 12:36, said:
3D, without an agreement firmly in place, is not defined in the Stayman convention. Therefore, any player that makes this bid has announced that he/she either:
A. is an idiot
B. is a mastermind who has no respect for partnership
When this kind of bid situation occurs, I follow the rule that - if the bid could be natural - it is to be treated as natural. Hence I would assume that opener elected to open 1NT holding a 6 card diamond suit with a 6322 pattern.
What's more, unless I had game forcing values, I would always Pass 3D, hoping to have partner play there. After all, that is what a mastermind partner wants ... and alternately, if partner is an idiot, it is what an idiot partner deserves.
This feels like a 99% unnecessarily aggressive, 1% constructive post. OK, so it's not a good idea to make undiscussed bids and it's a reasonable treatment to say "if it could be natural, then it is". But you can't have an agreement for EVERY auction; it feels very harsh to call anyone who pushes the boundaries of agreements just slightly when their hand warrants it an "idiot" who isn't deserving of their partner.
Here South has overcalled with 2D so the odds of you wanting to play in 3D - in a 6-1 fit facing a 5-1 break if you're lucky? - are slim to none. (Furthermore, presumably X would be penalty interest, given that you could just bid a major or pass otherwise?)
[Edit: Just seen the OP provided a hand as well, with three diamonds. So if West has 6 of them and South 5+, there are least fourteen in the pack...]
The bid either has to mean
1) MAX, no major, no diamond stop - and only if you don't play garbage stayman. The idea being that pass would show the same hand but minimum, while with a MAX you want to force to game.
2) 4/4 majors
and I think the second meaning is the more practical of these by far, so though it would take me a bit of thought to get there, that's what I would reason at the table.
ahydra