[aguahombre]

during one of my hiatuses from bridge, 1430 came in. I don't want to really start a debate about it, unless that is the way it goes. Rather, I just have some questions which my research failed to answer:

1) Is 1430 now the prevalent choice? (At one time, I saw it was only about 1/3)
2) Is the situation where HTs are trump and responder has one ace the only real
advantage? (so that 5D can be Q ask)
3) Is the probability of 1 key more than of 0 keys for 2) above?
4) Does it matter that 4NT is only RKC if a Major is established --when choosing which to use?

[mikeh]

aguahombre, on Nov 18 2009, 04:59 PM, said:

during one of my hiatuses from bridge, 1430 came in.  I don't want to really start a debate about it, unless that is the way it goes.  Rather, I just have some questions which my research failed to answer:

1) Is 1430 now the prevalent choice?  (At one time, I saw it was only about 1/3)
2) Is the situation where HTs are trump and responder has one ace the only real
    advantage?  (so that 5D can be Q ask)
3) Is the probability of 1 key more than of 0 keys for 2) above?
4) Does it matter that 4NT is only RKC if a Major is established --when choosing which to use?

1. my experience, bearing in mind that I don't play much tournament bridge these days, is that 1430 is the most common style. others with broader experience may differ, but watching on BBO seems to support this.


2. It helps in hearts and may in clubs as well. If you assume that the zero response will be infrequent, compared to the 1 response.... using 1430 will allow you to stop in 5♣...of course, a zero response forces to 5N or a possibly doomed slam...but fewer and fewer players use 4N as keycard in a minor anyway.

It may help in spades as well, depending on your Queen-ask structure.....if a 1 keycard response is more frequent than a zero, we can expect to use 5♦ queen ask more often in 1430 than in 0314, and now we have a 5♥ response to the queen ask, that can be used to convey information. So 1430 increases the usable space more than does 0314.

3. As suggested in (2), in my view, the odds of a zero response should be far below those for a zero response. Unless asker has a truly enormous hand, which is low-frequency, responder rates to hold at least one keycard on any set of hands warranting slam exploration.

4. I don't think so....

[ggwhiz]

1. Yes. The most prevalent password to club security alarms or voice mail is now 1430.

2. No. If clubs are trumps and 1 key is not enough you park it in 5 of them.

3. No. Entirely random if you bid like me. My first ever game with an expert partner, I keycarded on hearts and got a 5 spade response, off 2 aces. Is that any different than straight blackwood in clubs, pard shows 1 and it's not enough?

4. Sure does as to 2. above and I would think the queen ask with specific kings useful towards a grand or 6nt at matchpoints.

[Mbodell]

1. Yes. I'd say that it is about 75/15/10 locally between 1430/non-keycard/3014.

2. Yes, that is the main advantage. But in general the advantage is that in most situations the 5♣ answer will be more common than then 5♦ and the added room will help with your Q ask and give you more room to show K and then later 3rd round asks as well. Kanter has a book on keycard that covers complex rules for switching between 1430 and 3014 depending on who has shown what so that 5♣ stays the "common" answer in all forms (I.e., different if you are the strong 2♣ opener to if you are the responder, etc.), but almost no one plays that as it is too much memory/risk for too narrow a gain.

3. Yes. Even more importantly, the probability of wanting more information to explore slam is greater likelihood over the 1(4) answer than the 0(3) answer. Most of the time when you KC you will have 3 (or 2) KC yourself. If the answer is 0, you will generally be signing off. If the answer is 1 and you have 3 you may want to make the Q ask. Therefore you should optimize your room for asking more questions over the 1(4) answer instead of the 0(3) answer.

4. Not really, even when playing kickback in all 4 suits, or minor wood or what not, the argument about wanting more exploring room over the 1 answer still applies so if you are only ever going to use one form, you may as well use 1430.

[Jlall]

1430 is more common now, I doubt it matters much but as mentioned, it's so that 5C will be more common than 5D as a reply which must be good.

[blackshoe]

Kantar's original argument for 1430, as I recall, is that it allows room enough to ask about the Queen when hearts are trump and replier has one key card, without getting beyond 5 of the trump suit if he doesn't have the queen. That argument isn't really relevant if you're using Kickback.

I have several partners though, who think that 1430 is, as some of them would put it, the cat's pajamas. So even playing kickback, they want to switch the first two responses. I don't really have a problem with that - though I might if I found it difficult to remember they're switched over how I learned them many decades ago.

[Jlall]

Huh, it doesn't matter if you play kickback or not, you want the first step to be more common than the second step so that you save room in general. You can think about how using that room will manifest itself into good stuff, but the general point should be obvious enough that you don't have to.

In a completely ideal world you would play 0314 if you had shown a strong hand where 3 is more likely than 1, and you would play 1430 if you had shown a weak hand. And if you had shown a very weak hand where 0 was more likely than 1 you wouldn't even play normal keycard since you can't have 2+ (which is why responses to keycard after a preempt are often specialized).

Of course nobody but kenrexford is that precise, so you just go with 14 is more common than 03 by far on average in keycard auctions.

[cherdanno]

I didn't know kenrexford is Kantar's pseudonym, now it all makes sense!!!