[mr1303]

Apologies for no hand diagram - on holiday this month and I only have my phone.

AJxxxx
AJxx
Kxx
-

Opposite

KQ10xx
KQx
Ax
Kxx

Simple auction: (North dealer)

1S 2NT (Gf raise)
3C (shortage) 4NT (RKCB)
5S (2+Q or extra length) 6S

North thought that you shouldn't show a void in response to RKCB after showing shortage. South expected a missing ace.

Who should have bid differently?

[The_Badger]

Deleted. Thought South was dealer - Thank you NickRW

[NickRW]

The_Badger, on 2017-July-12, 03:37, said:

Blame North. Having used a Jacoby 2NT GF, he then blasts 4NT with a void...

Surely it was South who invoked Blacky

[Cyberyeti]

The 6♣ response to 4N is beyond obvious, however 4N is a terrible bid.

What do you propose to do over a 5♥ response ?

Does partner have AJxxx, AJx, Qxxx, x where the slam is almost no play or the 5431 hand with his actual honours where it's cold ?

[NickRW]

Realistically there are too many vital features of the North hand for South to find out for South to captain this auction. If South concentrates on showing features with say 3D over 3C and 4H over a probable 3H rebid, now North can start to envisage great things.

[Siegmund]

A slower auction MIGHT have helped --- long as you have ways to tell aces and voids apart and won't accidentally end in 7NT after 1S-2N, 3C-3D, 3H-3S, 4C --- but the actual auction would have worked just fine if North had bid 5NT to show 2 and a void. The difference between a singleton and a void is the main extra thing North needs to show here. Some people find it important enough to build it right in to their Jacoby responses.

[PrecisionL]

Jump to 4NT over 3♣? Terrible bidding. This is not a hand for Blackwood, give N a chance to cue 4♣, thereby showing a void and you find out if he has any kings also by cue bidding 3D (A or K since it is under game).

[Zelandakh]

mr1303, on 2017-July-12, 03:23, said:

Who should have bid differently?

Both...but I blame North more. Not calling 5NT here (or 6♣ if you play inverted as CY seems to) is ultimately the reason for the poor result.

[dokoko]

100% South.

By bidding BW with plenty of space available he denies interest in learning about a possible void. Partner might want to ask for ♦K, however.

[Cyberyeti]

Zelandakh, on 2017-July-12, 09:38, said:

Both...but I blame North more. Not calling 5NT here (or 6♣ if you play inverted as CY seems to) is ultimately the reason for the poor result.

Actually we only break with 2 aces, and 5N is w/o Q or extra length, 6♣ is 2 with + void, we don't split odd/even.

We'd have a completely different auction here as we bid length not shortage over 2N so the value of ♥KQx becomes obvious fast knowing partner holds 4 or more, if you know he has AJxx, you don't even need him to hold ♦K.

[rmnka447]

I agree with the sentiment of most that the jump to 4 NT was just plain wrong.

Even if the ♣ K is a wasted value, South's hand is a terrific hand for North. Every other honor in the hand is working. So, South should go slow and cue 3 ♦.

Look how much more information you both have if you do so.

1 ♠ - 2 NT
3 ♣ - 3 ♦
3 ♥ - 3 ♠ (3 ♠=waiting bid show continued slam interest)
4 ♣ - 4 ♥

At his point, North knows South has at least ♦ A and ♥ K, South knows North has ♥ A and ♣ void or stiff A. And someone can still use RKCB.

Given the actual auction, North has to make the appropriate void response (5 NT or 6 ♣) showing an even number and void. Whichever it is, South should be able to get the additional information to bid the grand by a further ask.