[arepo24]

What is the rule when both a C and a NT have been bid and one wishes to ask for Aces, which must they use? Gerber (4C) or NT (4NT)?

[barmar]

Isn't this basically what you were asking in your other thread?

You can make up any agreement you want with your partners, but the common approach is that it's Gerber if it's jump to 4♣ and one of you has bid NT naturally.

[blackshoe]

There are, I think, four approaches:

1. Four clubs is always Gerber.
2. Four clubs is never Gerber.
3. Four clubs is Gerber only directly over an opening 1NT or 2NT bid (or a strong artificial sequence ending in 2NT).
4. Four clubs is Gerber if it's a jump and NT has been bid naturally.

I think 3 and 4 are more common than 1 or 2, 2 is probably not common enough, 1 may be too common. As between 3 and 4, I would have thought that 3 was more common, but that may be because it's the one I prefer.

There are other sequences in which 4 clubs asks for keycards, but those, I maintain, aren't Gerber. There are sequences where 4 clubs is a jump, but it's not Gerber, it's natural.

There is no "Rule" per se. Certainly not in the sense that laws and regulations are called rules.

[arepo24]

So now I have received the answer I was looking for.
Barmar said, there is no rule. It is purely a partnership agreement. That's important to know.
And Blackshoe said pretty much the same thing.
So had I worded my original question properly, I would have gotten the answer I needed, so I thank you both.
CASE CLOSED!!

[Zelandakh]

blackshoe, on 2020-June-10, 08:57, said:

There are, I think, four approaches:

Here are a few of those key card possibilities that I would argue are much more common than any of the 4 listed:-

5. 4♣ is RKCB for ♣
6. 4♣ is conditional KCB for ♣
7. 4♣ is a slam try for ♣ starting cues
8. 4♣ is conditional KCB for ♣ and 4♦ is RKCB for ♣
9. 4♣ is a slam try for ♣ starting cues and 4♦ is RKCB for ♣

No doubt there are plenty of other combinations if I think about it for a couple of minutes. In any case, this and the other thread show clearly that the OP has completely the wrong way of thinking about slam bidding. First work out if you have the right hands for slam and only then work out if you are missing 2 aces. Any ace (or key card) asking convention is not a slam try; it answers a specific question to avoid bad slams after you have decided the hands justify bidding a slam absent 2 quick losers.

[bluenikki]

Zelandakh, on 2020-June-10, 14:44, said:

Here are a few of those key card possibilities that I would argue are much more common than any of the 4 listed:-
♣lubs] is RKCB for ♣
6. 4♣ is conditional KCB for ♣
7. 4♣ is a slam try for ♣ starting cues
8. 4♣ is conditional KCB for ♣ and 4♦ is RKCB for ♣
9. 4♣ is a slam try for ♣ starting cues and 4♦ is RKCB for ♣

No doubt there are plenty of other combinations if I think about it for a couple of minutes. In any case, this and the other thread show clearly that the OP has completely the wrong way of thinking about slam bidding. First work out if you have the right hands for slam and only then work out if you are missing 2 aces. Any ace (or key card) asking convention is not a slam try; it answers a specific question to avoid bad slams after you have decided the hands justify bidding a slam absent 2 quick losers.

A famous or notorious case of option 5. Dorothy Haydn proposed it to B J Becker that 4♣ be Gerber even when clubs were agreed. Becker said ok but promptly forgot.

Not long after, he found himself playing 6♣ on a 4-2 fit. (Not 6-2, as I mis-typed before.) His bridge face was secure enough that he did not get a trump lead. Without the trump lead, playing out the string, he noticed big problems in the opponents' demeanor, and the contract could not be set.

[Zelandakh]

bluenikki, on 2020-June-11, 11:59, said:

A famous or notorious case of option 5. Dorothy Haydn proposed it to B J Becker that 4♣ be Gerber even when clubs were agreed. Becker said ok but promptly forgot.

Not long after, he found himself playing 6♣ on a 4-2 fit. (Not 6-2, as I mis-typed before.) His bridge face was secure enough that he did not get a trump lead. Without the trump lead, playing out the string, he noticed big problems in the opponents' demeanor, and the contract could not be set.

There is a write-up of it here complete with diagram. The story goes that Mitchell's reaction was: "He couldn’t have made it without the six of hearts!". I can imagine that most modern players would rather react by calling the TD and claiming misinformation.

[smerriman]

arepo24, on 2020-June-10, 10:37, said:

Barmar said, there is no rule. It is purely a partnership agreement. That's important to know.

That is true about every single bid in bridge.

[Vampyr]

bluenikki, on 2020-June-11, 11:59, said:

A famous or notorious case of option 5. Dorothy Haydn proposed it to B J Becker that 4♣ be Gerber even when clubs were agreed. Becker said ok but promptly forgot.

Not long after, he found himself playing 6♣ on a 4-2 fit. (Not 6-2, as I mis-typed before.) His bridge face was secure enough that he did not get a trump lead. Without the trump lead, playing out the string, he noticed big problems in the opponents' demeanor, and the contract could not be set.

This reminds me of some MSC hands where you had to bid the only making slam on a known 4-2 fit.

And who can forget the 3-2 slam hand in one of the Menagerie books.

[msjennifer]

Sir,Although there are no rules as such I have got the gist of the problem.When as said the club is the agreed suit we use a bid of 4D as RKCB, unless three cue bids have been made before that.Thx

[jaysmother]

This is the same as his other question.

[miamijd]

bluenikki, on 2020-June-11, 11:59, said:

A famous or notorious case of option 5. Dorothy Haydn proposed it to B J Becker that 4♣ be Gerber even when clubs were agreed. Becker said ok but promptly forgot.

Not long after, he found himself playing 6♣ on a 4-2 fit. (Not 6-2, as I mis-typed before.) His bridge face was secure enough that he did not get a trump lead. Without the trump lead, playing out the string, he noticed big problems in the opponents' demeanor, and the contract could not be set.

No, it was a 5-3 fit. Trump were OK. Problem is that he was off three cashing H tricks. But the opponents didn't find the H lead, and Becker was able to execute a neat Morton's Fork sort of endplay.

[DarylK]

arepo24, on 2020-June-10, 08:23, said:

What is the rule when both a C and a NT have been bid and one wishes to ask for Aces, which must they use? Gerber (4C) or NT (4NT)?

In the UK Gerber is becoming much less popular. Playing standard systems after NT rebid/response, 4NT is always quantative regardless of whether you play Gerber.

[Zelandakh]

DarylK, on 2020-June-12, 15:22, said:

In the UK Gerber is becoming much less popular. Playing standard systems after NT rebid/response, 4NT is always quantative regardless of whether you play Gerber.

Popular in the UK since my childhood has been a 4♣ response showing both majors at least 5-5, something I took to calling Extended Texas, though what the official designation might be I have no idea.

Another popular convention back then was 2♠ as a Baron range ask and several pairs chose to put their quantitative slam invites through that rather than a direct 4NT. Similarly, with Texas transfers it is not uncommon to use 4♠ as a Baron range ask that also covers quantitative invites. In both cases a direct 4NT becomes available for another use. The best I have come across so far is using this as a transfer to 5♣ but there are other options, including using it as a natural invite of a slightly different type.

In any case, the point here is that 4NT may not always be quantitative if that does not mesh well with other parts of the structure. In general though, yes, it is the default meaning absent a special agreement.