Anyways, our partnership agreement is that style 2 is the general methodology. So, declarer should have the Q. But, part of the attraction is the intellectual challenge/stimulation, right? Let's say we had chosen to adopt style 1 and take a closer look.
What can we deduce about the heart suit? Partner could always afford a heart with five of them, so declarer is very likely to have at least three. If declarer has at least three hearts, then game always makes if he's got the K as well, unless we take the ace and can cash three club tricks, i.e declarer having
That would give partner...
... and I can't see the 5 of diamonds discard coming from this holding. I'd let go of my lowest diamond then to inform partner I have a high card there. That should help him see that ducking a diamond is useless and that setting tricks must come from other suit(s). The problem then is that partner wouldn't know which K to play me for. But that dilemma is solved by our second diamond play. We'd follow low with club interest and high with the K of hearts. This information is more important than length at this point.
So, after that diamond discard let's place the K of H with partner and it seems reasonable to place declarer with either the Q of diamonds or the K of clubs because otherwise he'd only have 9 hcp at most. (Sidequiz: would a heart discard indicate original length or show/deny another honour?)
Doesn't that mean we can now fly the ace of diamonds (anyway) and put partner in with K of hearts for a club through and collect the setting tricks?
The answer is maybe. What if declarer has a stiff club? Could he have a singleton? With a stiff K, declarer would probably have led a club from dummy at trick 3, or partner might have discarded a club from Jxxxx. But what about...
Now we have to duck.
Is 6-3-3-1 then a possible shape for declarer? I could see partner letting go of a diamond from a short holding with both K's.
I'd discard the 5 of diamonds from this holding, not wanting to emphazise either sidesuit.
Edit: It has been suggested elsewhere that one would never discard from a three-card holding here, rendering this layout impossible. I say one should consider letting a diamond go from 532 as well. If you always discard from your longest suit(s), you'd be an easy read for a competent declarer. Here, if declarer has QTx (vs K97) this diamond discard might lead him astray, playing you for an original Jxxxx. Don't be too rigid in your approach here.
Summing up: The only time the setting trick could go away, by ducking, is when declarer has a stiff diamond and partner has discarded the 5 from QT532. Otherwise we just wait for declarer going down, getting one heart trick and either two diamonds and a club or a diamond and two clubs (catering to either layout). I can't construct a reasonable layout where partner would have QT532. And, as stated above, is that really possible with the actual partnership agreement? So, ducking must be right.
Anyone with a differing opinion?