[y66]

4D

Move forward in diamonds now. Hope pard can bid 4H or 4S.

Like this problem a lot.

Will save this for future partnership discussion of slam methods, including ... 4D 4S 4N=6KCB and ... 4D 5C=?

[ArtK78]

Seems like 4NT over 3♦ is the practical approach. You will get to 6♦, 7♦ and 6NT or 7NT on most hands where each of these contracts is likely to make. All that you will miss is the occasional 6♠ contract (it is unlikely that 7♠ will make on hands where 7NT does not also make).

The only other possibility is that you should be in 4♠ rather than 5♦, but that is a very unlikely possibility (partner holds xx xx JT9xxx KQJ and the diamond Q does not come down).

[HeavyDluxe]

Another non-expert response... But I'd bid 4NT, RKC for ♦s.

4♦ is my second choice.

I'm opening 2♣ mostly with big one-suiters, right? So, I'd hope responder would suspect a 6 card ♠ suit anyway. Instead resp has pushed ♦s and I have massive, supportive hand. As is noted in previous posts, I'm betting on a possible 7♦ or finding a small or grand slam in NT.

[mtvesuvius]

My original thought was to bid 3♥ hoping for a ♠ correct back, but now this creates horrible problems when partner does not bid 3♠, in addition to the fact that knowing about ♦ is much more important. I bid 4NT. And I agree with Han's analysis of what to do after partner responds to 4NT... In a club game I think 7♦ is now safest, but in most National tournements etc, now there is a decision to be made... (and without fail, I'll always make the wrong one)