[Hanoi5]

1♥-2♠*
3♦-4NT

2♠ shows 6+ solid or semi-solid spades, a one suited hand with 13+ HCP's. Opener will usually show support with a singleton honour or even 2 small spades. 3♦ is natural, so what should 4NT be? Diamonds KC? Quantitative? Wgo's the 'captain' of this sort of auction? Can the 'Captain' of an auction bid a quantitative question?

[TylerE]

I think it's RKC for ♦, but I would fully expect the final contract to be in ♠. A hand like AKJxxxxxx Kx Qx x perhaps?

[cloa513]

Hanoi5, on 2013-July-08, 21:34, said:

1♥-2♠*
3♦-4NT

2♠ shows 6+ solid or semi-solid spades, a one suited hand with 13+ HCP's. Opener will usually show support with a singleton honour or even 2 small spades. 3♦ is natural, so what should 4NT be? Diamonds KC? Quantitative? Wgo's the 'captain' of this sort of auction? Can the 'Captain' of an auction bid a quantitative question?

I think 4NT should be something unusual like six very solid spade-versus a void and AQ or AJ10 of clubs. 3H should be a general purpose force- could be over strength NT or hearts support or moderate slam potential spades without club cover. 3S should be a different force Good spades overstrength either poor slam potential or too strong slam potential- without much in clubs.

4C is cue for diamond. 4D is minorwood. 4H is a cue for diamonds.

[aguahombre]

As someone ably pointed out in another recent thread, "Quantitative" is a description, not a question. Whatever Responder did at his second turn (non-game) would have been forcing. 4D would have agreed Diamonds; 3NT would be to play and minimum. 4NT feels like 7 solid spades and the guarded king of clubs. Opener should be the captain --he has not limited his hand at all, and hopefully the blaster has done so.

It is important, whatever you want space-gobbling jumps in a forcing auction to mean, that you agree in advance what descriptions they convey.

[Zelandakh]

Seems clear that it is natural without any special agreements, since other hand types have an obvious alternative:
3♥ = heart support
3♠ = sets spades as trumps
3NT = to play
4♣ = diamond support, demands cue bids (4♦ = club cue)
4♦ = diamond support, slam try
4♥ = RKCB for diamonds
4♠ = to play
4NT = natural
5♣ = XRKCB for diamonds

Change 4♣♦♥ according to your own rules for 4 level minor suit agreements. This is one of those "advanced" Kickback situations where you can play it in combination with a natural 4NT. If you are playing simple Kickback, or no Kickback at all, then you have to agree diamonds first and then bid 4NT on the following round.

As for Captain making a quantitative bid, is that the normal way around? If I open 1NT (or 2NT) then partner is (initially at least) Captain. If they now bid 4NT then it is traditionally quantitative. Making a quantitative 4NT raise is not greatly different from bidding an invitational 2NT; it is just that the range is a little higher.

[Free]

To set ♦, ♥ or ♠ responder could've just raised them. So RKC is foolish. What's left is a natural meaning, quantitative, basically showing a hand with extras but not enough to commit to slam.