[vtgardener]

While playing with a robots I occasionally get into a slam bidding inquiry and am asked by my robot partner to announce my keycards. I just had a strong hand which included several aces, king of trump suit, plus a void.

I know an earlier splinter bid would indicate shortage. But how else to show my void? Tia.

[DavidKok]

I think a full answer would have to be in 3 parts.

Firstly, most people playing RKCB have an agreement that a 5NT response shows an even number of keycards with a useful void (it's useful if partner has not shown length in the suit), a jump to 6 in any suit lower than the trump suit promises an odd number of keycards with a useful void in the bid suit, and a jump to 6 of the trump suit shows an odd number of keycards with a useful void in a suit higher than the trump suit. Voids that are not useful are not shown.

Secondly, a lot of bidding systems strain to show shortness + fit earlier in the auction. If your partner was ready to bid 4NT (or some other keycard-asking bid) and you have undisclosed shortness there is a good chance the bidding up to that point can be improved upon. Giving partner an accurate picture if your hand is vital, and doubly so if slam might be on.

Thirdly, the player who makes a keycard-asking bid is taking captaincy of the auction, stating that they are close to certain they know what level the partnership should bid to but for the risk of losing quick tricks. Typically if you have shortness you are in a much better place to judge this than partner, so you should strive to take captaincy of the auction before that point. Some people use gadgets such as Exclusion Blackwood, which incidentally takes captaincy.

[smerriman]

The above points are all very good when it comes to humans. But given you mentioned robots, just to add a fourth point - while GIB does have the void responses mentioned in point 1 above, it regularly launches into RKCB way earlier than it should due to having poor control bidding logic (ie it fails at points 2 and 3). So if you're missing slams due to the 4NT bid, there's a decent chance its the robot's fault.

[thepossum]

You also have to bear in mind that an even number of keycards and a useful void can mean no keycards and a useless void with GiB

[barmar]

thepossum, on 2021-March-29, 03:18, said:

You also have to bear in mind that an even number of keycards and a useful void can mean no keycards and a useless void with GiB

Unfortunately, GIB's basic hand evaluation doesn't distinguish between shortness in partner's suit and shortness in other suits. But when it does simulations, this will usually discover the value of shortness in opponents' suit.

[Zelandakh]

RKCB has various levels of use. Some play it knowing only the first 4 direct responses to 4NT. Some play it knowing also about the trump queen ask. Some can add in king asks. Very few know it as far as SSAs. And that is before one gets into the world of Minorwood, Redwood and Kickback. One of these extensions to basic knowledge is void-showing responses:-

suit agreement - KC ask
==
1st step = 1 or 4 kc (0 or 3 if playing 3041)
2nd step = 0 or 3 kc (1 or 4 if playing 3041)
3rd step = 2 or 5 kc without trump queen
4th step = 2 or 5 kc with trump queen
5th step = even number of kc and a useful void
others = odd number of kc and a useful void

The best advice I can give here would be to read through Kantar's notes, which are available online without cost from Dan Neill's excellent website. If you have additional questions after absorbing that, this is an excellent place to come back to and get the answers.

[blackshoe]

Somewhere around here I have a five or six book series on RCKB (written by Mike Diesel, not Eddie Kantar). One of the better local players, when I mentioned this series, said dismissively "nobody need six books to learn RKCB". I think he's wrong about that.

The first book, "the basics" has ten rules for basic RKCB. IIRC in total there are 37 rules.

Vince Oddy's site has a pretty good description of the first four volumes. The first five are available on amazon, at least the first four in kindle editions. Not sure volume six ever got published.

[thepossum]

Are there any top world pairs still using standard Blackwood? It seems simpler

[barmar]

thepossum, on 2021-April-07, 17:30, said:

Are there any top world pairs still using standard Blackwood? It seems simpler

I would guess no. If they're not playing basic RKCB, they're probably using some other variants like Kickback and Minorwood. The trump king and queen are critical cards, so they all use methods that allow these to be shown.

[pescetom]

Zelandakh, on 2021-April-07, 07:09, said:

Dan Neill's excellent website.

Wow, what a resource. Thanks.

[pescetom]

Zelandakh, on 2021-April-07, 07:09, said:

And that is before one gets into the world of Minorwood, Redwood and Kickback.

There is also Crosswood, which has advantages over the first two and is less stressful than the last.
But using clubs as asking strain over diamonds raises some problems that even Kantar never thought about - there is no such thing as a free lunch.

[Zelandakh]

pescetom, on 2021-April-09, 15:39, said:

There is also Crosswood, which has advantages over the first two and is less stressful than the last.
But using clubs as asking strain over diamonds raises some problems that even Kantar never thought about - there is no such thing as a free lunch.

If agreeing ♦ at the 3 level without clear slam interest:
==
3♥ = stopper ask or advanced DCB
3♠ = stopper ask or advanced DCB
3NT = to play
4♣ = DCB ♣
4♦ = CKCB
4♥ = RKCB
--

If agreeing ♦ at the 3 level with slam interest (3NT in picture):
==
3♥ = general slam try (Frivolous)
3♠ = ♠ control ask (serious)
3NT = to play
4♣ = ♣ control ask (serious)
4♦ = ♥ control ask (serious)
4♥ = RKCB
--

If agreeing ♦ at the 3 level with slam interest (3NT not in picture):
==
3♥ = general slam try (Frivolous)
3♠ = ♠ control ask (serious)
3NT = ♥ control ask (serious)
4♣ = ♣ control ask (serious)
4♦ = RKCB
--


If agreeing ♦ at the 4 level (♣ not in picture):
==
4♣ = CKCB
4♦ = asks for cue auction
--

If agreeing ♦ at the 4 level (♣ in picture):
==
4♦ = CKCB
4♥ (if available) = RKCB
--

More complicated rules are possible but, like Kantar, I do think that at a minimum treating 3m and 4m agreement differently is useful.

[pilowsky]

Since you are playing with GIB - which is pretty rigid in terms of partnership agreements, here is what I have found.Personally, I find the relationship between the bids, the meaning and the possible outcome fairly tight.


The GIB slam bidding methods are not as intricate/sophisticated as some of those outlined above but they are outlined in detail in the GIB system notes.
Over a call of 4NT, I generally find the Robots land in a reasonable slam - even if I play badly and don't make it.
Here is a link to the system notes where the meanings are outlined in detail.
https://bit.ly/GIBsystem