[Walddk]

Please be honest; Are you sure that 4NT is always Blackwood/Roman Key Card for you and your partner? Some kind of Blackwood is used by roughly all bridge players worldwide, but do they always know if 4NT is Blackwood or not?

Let me give you some examples:

1.
1NT-2♣
2♥-4NT

Is 4NT ace asking for hearts or quantitative with 4 spades?


2.
1NT-2♣
2♠-4NT

Is 4NT ace asking for spades or quantitative with 4 hearts?


3.
1♠-2♦
2NT-4NT

Is 4NT ace asking for diamonds, maybe just 4 ace asking, or is it quantitative?


4.
1♥-2♣
2NT-3♠
3NT-4♣
4NT

This is even more complex. Is 4♣ natural or ace asking? If natural, is 4NT natural sign off or ace asking?


5.
1♠-2♦
2♥-4NT

Is 4NT ace asking for hearts or quantitative with one or more club stoppers?

....

I could give you many more examples, but try these first. Are you sure you and your partner are on the same wavelength? Any agreement could work fine, but it's important that you both know what 4NT is whenever it is used.

Roland

[hotShot]

Our agreement is:

1) If we have an supported fit, 4NT is always RKCB.
2) A jump to 4NT after partner bidding a new suit is RKCB for this suit.
3) Partner bid NT (usually no suit bid), 4NT is quantitative
4) No fit, No jump means 4NT is to play

So in you examples:
Blackwood: 1, 2, 5
Not Blackwood: 4

Well you got us with 3, but I guess it's quantitative.

[mr1303]

For me, 4NT is very rarely Blackwood.

1 is quantitative with 4S (if 2C was stayman). I have ways of showing slam tries after agreeing hearts here.
2 is quantitative with 4H
3 is just quantitative. I can bid 3D here as forcing
4 is a natural sign off. Opener must have a very bad hand for slam purposes on this auction. 4C was natural and forcing btw
5 is RKCB for hearts here. If I had a normal raise to 4NT quantitative, I could bid 4th suit and raise partner's 3NT to 4NT, or do something else if he didn't bid 3NT.

[helene_t]

The reason to use Blackwood at all (rather than Gerber) is that the 4-level is used for something else. So bypassing the 4-level, 4NT will rarely be Blackwood. Therefore, 3) is clearly quantititive and 4) is clearly a sign-off.

1) and 2) should be quantitative. If you use 3♦ (or something else) as a forcing raise, use that before using Blackwood. Otherwise, play Gerber in this situation.

As for 5), 3♥ should be forcing. If it's not, play Gerber. I'm not sure if a quantitative 4NT makes much sense here, but at least it makes more sense than Blackwood.

I don't think Blackwood should be recomended for beginners and intermediates. It's a rather useless convention and even experts can't tell all the different meanings of 4NT apart. It's possible that Blackwood makes sense for advanced players in a few specific situations. Such as the special case of kick-back in which the agreed trump suit is spades.

[whereagles]

Here is how I would see it.

1 and 2. Depends on what you agree with pard. I used to have agreed

1NT-2C-2D-4C/4NT = gerber/quantitative
1NT-2C-2M-4C/4NT = fit + control/RKCB
1NT-2H/S-x-4C/4NT = fit + control/RKCB

3. Quantitative, as I see it. Pard has at least a dozen ways to set trumps, so a direct 4NT can be natural.

4. Quantitative, from a logical point of view. Opener MUST have a bid to say "I am not interested in slam, please pass", and that can only be 4NT.

5. RKCB for hearts. If resp wants to invite slam with a fair hand, he can bid 4th suit and follow up with 4NT. Since he didn't do that, 4NT should be RKCB for last suit bid.

But, of course, the "correct" answer is always what you agreed with pard

[pclayton]

With my pards, all but #5 isn't BW.

#5 is interesting. I suppose if I held a 2254 18 count, I would want 4N to be natural (although 3♣ is fine). If pard was 100% sure that 3♥ is forcing; (wouldn't you make the call with: xx, AJxx, KQxxx, xx? ) then its probably the correct call.

[inquiry]

1. quantitative
2. quantitative
3. quantitative
4. Unwilling to cooperate towards slam
5. MOST CLEARLY NOT BLACKWOOD

Let't look at number five. Responder, who made 2/1 GF 2D, has a way to make the auction forcing in hearts or spades by bidding 3♥ or 3♠. The fact that HE DID NOT do this, means 4NT is not blackwood. If he wants to blackwood he should first establsih trumps then make the bid. This is a good rule to live by. On #1 and #2, we play "other major" as agreeng first major trumps, and slam try. So to blackwood in the major your partner responded to stayman with, we bid the other major and then 4NT.

On number 3, to ask for aces in diamonds, FIRST clearly establish diamonds as trumps, with jump to 4D (I use that already as asking for aces), or nmf then rebid 4D then bid 4NT.

I am not sure #4 is even possible. 4♣ is a slam try, and responder is showing monster hand. Opener could cooperate by cue-bidding a red control, so I take this as... my hand is very red... and minimum/non=slam oriented for previous bidding.

Ben

[luis]

I would like to add the following sequences were I've seen fairly advanced players that can't distinguish between them:

(Assuming you play dreaded Texas, if you play South African transfers replace 4d with 4c)

1N-2d
2h-4N

1N-2d
2h-4h

1N-4d
4h-4N

[Stephen Tu]

1. quant
2. quant
3. quant
4. natural/signoff
5. I would avoid this sequence if I had a forcing 2nt bid available (since then I can bid 2nt ... 4nt as quantitative). If not, quantitative. If I wanted RKC for hearts, I can always bid a forcing 3♥ before 4nt.

My partnership meta-rules regarding 4nt are:
- if it sounds like it could be natural, it is.
- if your last bid was 3nt to play, 4nt is also to play
- if you have some way to unambiguously set trumps and have the auction be forcing, before RKC, you do it.

[keylime]

1. quantitative with 4 spades, clearcut. failed to set trumps. some play 4C after 2H as a RKC ask in hearts <ask pard>

2. quantitative with 4 hearts. see item one.


3.quantitative, due to the inability of the Gf'ers to name a second suit or to nominate diamonds as a likely six card suit.


4. natural signoff, possibly inviting six NT on right cards.



5. quantitative with one or more club stoppers - we don't use RKC as last suit bid.

[geofspa]

Quote

I would like to add the following sequences were I've seen fairly advanced players that can't distinguish between them:

(Assuming you play dreaded Texas, if you play South African transfers replace 4d with 4c)

1N-2d
2h-4N

1N-2d
2h-4h

1N-4d
4h-4N

If playing texas and jacoby transfers I would play that

1. quantative slam try

2. mild slam try asking opener to rebid something with a max hand

3. rkcbw ... or any other flavour of BW agreed with partner

[P_Marlowe]

1) quantitative
2) same as 1)
3) quantitative, you can always bid 4D, to initiate a slam
bidding sequence with diamond as trumps
4) RKCB for clubs since for me 4C is a natural
slam try, asking opener to start a cue bidding
sequence
The 2 NT rebid by opener shows a strong NT, 15-17 HCP,
and I doubt, that anyone can come up with a hand were
opener has no cue bid available, i.e. missing AK in diamond,
hearts and spade
5) RKBC for hearts, but the auction is unlikely
to happen, since you can always create a slam auction for
hearts using FSF, and the same is true for a quantitative
NT raise, which can also be shown via FSF, with the benefit
of stopping in 3 NT, when opener is minimum.

With kind regards
Marlowe

[Winstonm]

As for the sequences in the OP, without first bidding the other major as a slam try, the NT sequences are all quantitative. #4 is a signoff. #5 is Blackwood in hearts.

Although not concerned with NT sequences (which I think partnerships should have down pat), this is an interesting addition to the bidding arsenal:

http://www.bridgeguy...r_no_trump.html

[Cyberyeti]

1: we use 4♠ as keycard and 4N as quantitative
2: we use 4♥ as an artificial slam try (usually followed by 4N), 4N as quantitative
3: system dependent, what does 2N show ? weak/strong NT system ?
4: see 3
5: depends if 2♦ was GF

[ggwhiz]

Winstonm, on 2018-July-14, 10:44, said:

Although not concerned with NT sequences (which I think partnerships should have down pat),

http://www.bridgeguy...r_no_trump.html

I agree, play all of the above and used to play DI 4nt too. Therefore 1-4 are quantitative.

Another that all should have down pat is

1♠ - 2♥ (gf)
3♥ - 3♠

4nt later by opener OR responder, what's the key suit?

[pescetom]

1. Quantitative with 4♠
2. Quantitative with 4♥
3. Quantitative NF (partner 12-14)
4. Natural
5. Illogical/undefined (partner 11-21, no duress, 2NT forcing)

[smerriman]

Winstonm, on 2018-July-14, 10:44, said:

As for the sequences in the OP, without first bidding the other major as a slam try, the NT sequences are all quantitative. #4 is a signoff. #5 is Blackwood in hearts.

Although not concerned with NT sequences (which I think partnerships should have down pat), this is an interesting addition to the bidding arsenal:

http://www.bridgeguy...r_no_trump.html

A 13.5 year bump must be some kind of record, right?

[pescetom]

ggwhiz, on 2018-July-14, 11:47, said:

Another that all should have down pat is

1♠ - 2♥ (gf)
3♥ - 3♠

4nt later by opener OR responder, what's the key suit?

For us the key suit is fixed in ♠, and this sequence invites a control-bid by opener.
But the important thing as you say is to have this down pat.

[pescetom]

Winstonm, on 2018-July-14, 10:44, said:

Although not concerned with NT sequences (which I think partnerships should have down pat), this is an interesting addition to the bidding arsenal:

http://www.bridgeguy...r_no_trump.html

It's an interesting piece of history but I would rather add Turbo to the arsenal.

As an aside, does anyone know why the bridgeguys site has such a peculiar halting style of English? It reads as if it has been translated to Portuguese and then back again

[heart76]

Quote

1.
1NT-2♣
2♥-4NT
2.
1NT-2♣
2♠-4NT

Specific partnership agreement is required. 4NT as RKCB here is basic level (KISS); jump to the other major slam invitational w/support while 4NT quantitative more advanced, most likely besides Texas+4NT as RKCB to differentiate hands; I think any system construction around (semi)artificial 3m bid for serious partnership is possible.

Quote

3.
1♠-2♦
2NT-4NT

As 2NT denies 4 ♥ and 6 ♠, for me 4NT is 100% quantitative with 5-6 ♦.
Playing 2/1,
3♠ would be 3 cards support and at least mild slam invitational.
3♣/3♥ is asking opener to confirm a sound stop in the unbid suit at 3NT.
3♣ can contain a slam invitational hand in a minor, e.g. 6 ♦ or 5-5+, which would re-open partner's 3NT.
3♦ would be 6+, looking for 3NT or a slam.

Outside 2/1 it would be again quantitative, with a bit different meaning for the other bids.

Quote

4.
1♥-2♣
2NT-3♠
3NT-4♣
4NT

This is even more complex. Is 4♣ natural or ace asking?
If natural, is 4NT natural sign off or ace asking?

4♣ is usually for me natural and slam invitational. It is also possible to allow it as Gerber, where 4♦ would be RKCB in ♣. Another option is Minorwood.

If 4♣ is natural and slam invitational, then 4NT denies 3 cards in support and shows a weak 5332.

I suppose one could agree that a such specific sequence shows 6+ ♣ and 5 ♠, at least slam invitational, but this is far away from my style.

Quote

5.
1♠-2♦
2♥-4NT

Is 4NT ace asking for hearts or quantitative with one or more club stoppers?

100% RKCB in ♥.
4th suit forcing would be the way to reach a 4NT quantitative, denying support for opener's suits.