[barmar]

Coelacanth, on 2011-September-27, 09:49, said:

I think (and those of you who are better bidders than me can refute this) that if West thinks she has made a control bid in clubs, then 5♣ (to this West) would be second-round club control and, by implication, first-round control of both red suits. This is not far from East's actual hand (there's no reason he couldn't have the ♦A instead of the king) but it doesn't make sense in the context of North doubling 4♣ for the lead.

If West had an opportunity to show controls in the red suits and bypassed them, East's return cue should imply those controls. But in the actual auction, 4♣ was West's cheapest cue bid, so East should then make his cheapest cue if he needs to continue cueing. If he has control of all the suits, he doesn't need to cue any more, he can use Blackwood.

[Coelacanth]

mrdct, on 2011-September-27, 15:08, said:

Accordingly, West may argue that once the 5♣ bid hit the table she has AI that the bidding is off the rails as 5♣ just doesn't fit any agreement or potential holding partner can have. In these circumstance, we might allow West to bash out 6♠ given that partner must have something extra over there to by-pass 4♠.

She didn't make this argument, but I think this is a good summary of her thought process when 5♣ came back to her. Surely, her partner has shown a non-minimum hand by bidding beyond 4♠.

[mycroft]

irrelevant to the discussion, but once the NT opener showed club cards, isn't that when you *want* a club lead? After all, the CK could be the setting trick, if I get a club lead. If I don't - especially if I get a diamond lead that sets up that suit - we might have just let a settable slam go down.

But I digress. It is important to know what their cue-bid agreements are here - if 5♣ shows 2nd-at-least control of the red suits, in a cue-bid auction (otherwise 4♠), then 6♠ is fine. Otherwise, I wonder about bidding slam with two losers in diamonds (although the double might just let that through, too).