[gerry]

The last board in the Cayne-Amoils match reminded me of what we used to call the 'negative slam double'.

As I recall double in these dive auctions shows 1 trick and pass shows 0 or 2? Then pard dives with 1, doubles with 0 and passes with 2?

Is this right, it seems to work provided that you don't end up diving when you have three defensive tricks!


Is it all worth it? What do other people do?

[Vampyr]

gerry, on 2012-March-22, 23:25, said:

The last board in the Cayne-Amoils match reminded me of what we used to call the 'negative slam double'.

As I recall double in these dive auctions shows 1 trick and pass shows 0 or 2? Then pard dives with 1, doubles with 0 and passes with 2?

Is this right, it seems to work provided that you don't end up diving when you have three defensive tricks!


Is it all worth it? What do other people do?

What does "dive" mean?

[Zelandakh]

Do you mean the DOPI and DEPO conventions? Perhaps it would be easier if you write the specific auction as it is not clear exactly what you mean here (to me at least).

[gerry]

Zelandakh, on 2012-March-23, 03:13, said:

Do you mean the DOPI and DEPO conventions? Perhaps it would be easier if you write the specific auction as it is not clear exactly what you mean here (to me at least).

You are considering a w/r sacrifice (dive) in 7♣ over the opponent's 6♠.

In order to avoid the ghost who walks (phantom) it might be useful to sort out combined defensive tricks. The idea, which I have not heard referred to in many years was that the player in the direct seat after the offending 6S would double to show exactly 1 defensive trick and pass with 0 or 2 defensive tricks. Now, partner knows what to do after a double, and after a pass s/he doubles with NO defensive trick, passes with 2 and takes the dive with 1.

[Codo]

I have heard about this approach, but do not like it.

The main problem for me is: How can I rate my defensive tricks? If I hold Kx in trumps, maybe Qxx? Is the ace in our suit a trick? What about KQx in a side suit? Will they discard all losers on another side suit?

[Zelandakh]

OK, now I know what you mean. This comes under the general heading of "Cooperative Slam Doubles".

Negative Slam Double is:-
X = 0 tricks
P = 1-2 tricks (then partner doubles with 0 tricks)

Positive Slam Double is:-
X = 2 tricks
P = 0-1 tricks (then partner doubles with 1 trick)

Other possibilities exist as well. The problem is the difficulty in actually assessing what a trick is. In general I have seen more disasters with these methods than successes but I daresay that with expert judgement they are effective.

[gnasher]

I don't know anyone who plays them, probably because they don't work very well - Codo's post explains why.

[gwnn]

Vampyr, on 2012-March-23, 02:06, said:

What does "dive" mean?

Bid, intending to sacrifice.

[Tomi2]

there are two other things, that make such conventions difficult to play:

a) you give up a lightner double, because the double by the non-leader can be assigned to x y or z tricks

b) you can't always say, when its "cheap" to go one level higher. say your partner is passed and you decide to disturb opps strong club with 3dia on kqjxx 5th and a side queen, they double and partner raises this dias. they come to the point where they bid 6 clubs, that is finally making on guessing that queen for 1370 (or -100 if they misguess). due to your silly agreement you and your partner bid 6dia for 1400
on the other hand if you want to prevent it, you may count that queen as a trick, let them maybe even play 6clubs doubled and help them to make?

had this convention on my card and it was one of the first i striked out

[han]

gerry, on 2012-March-22, 23:25, said:

The last board in the Cayne-Amoils match reminded me of what we used to call the 'negative slam double'.

As I recall double in these dive auctions shows 1 trick and pass shows 0 or 2? Then pard dives with 1, doubles with 0 and passes with 2?

Is this right, it seems to work provided that you don't end up diving when you have three defensive tricks!


Is it all worth it? What do other people do?

I had this agreement and it came up exactly once. Then we immediately scratched it. You can imagine why.

[bluecalm]

Quote

that the player in the direct seat after the offending 6S would double to show exactly 1 defensive trick and pass with 0 or 2 defensive tricks. Now, partner knows what to do after a double, and after a pass s/he doubles with NO defensive trick, passes with 2 and takes the dive with 1.

This is inferior to:
direct double = straight penalty
reopening double = 1 trick

The reason is that double them more often when you want to (ie. have 2 tricks in direct seat)

Anyway, even in that improved version I hate this convention and I think it only causes disasters.

[Siegmund]

I played negative slam doubles with one regular partner for many years, and had good success with it. I don't recall any penalties collected but do recall several cooperative sacrifices found that would have been nailbiter decisions or quiet 1430s without it. (Also at least once where we chose between 1660 and 1700 but that was the fault of a subminimum preempt not the double.)

It is true you have to guess some what to do with Kx/Qxx. But you have to guess whether those are tricks when you sacrifice without information from the double too.

I have been a big believer in them ever since I first read the 2-page description of them in Kearse, and was quite surprised to discover they were so uncommonly used. Back in the mid-90s I had the misapprehension that they were in very wide use by advanced players and it was just a choice between negative and positive.

But I've encountered widespread fear of them, much as described in this thread, when I have proposed them to several semi-serious partners the past couple years.

[Statto]

I'd prefer to have some systemic agreement along these lines at the 5 level instead, when our side is def not FP, opps might be. Any suggestions?

[gnasher]

Siegmund, on 2012-March-23, 20:32, said:

It is true you have to guess some what to do with Kx/Qxx. But you have to guess whether those are tricks when you sacrifice without information from the double too.

It's not just that you have to guess: it's also that you have to give away information. With a holding like Qxx, if you announce that you have a trick you may convert it into a non-trick.

[FrancesHinden]

The other problem is that playing them is a bit committal: apart from the difficulty of knowing when they apply compared to being able to make a Lightner double, you end up being obliged either to save or defend doubled. It's not uncommon on pre-emptive auctions that your save is going for as much as their slam, so sometimes we just want to pass them out quietly. If you only start pre-empting when you are cheap, you make it too easy for the opponents to know when to bid on.

[S2000magic]

Zelandakh, on 2012-March-23, 04:53, said:

OK, now I know what you mean. This comes under the general heading of "Cooperative Slam Doubles".

Negative Slam Double is:-
X = 0 tricks
P = 1-2 tricks (then partner doubles with 0 tricks)

Positive Slam Double is:-
X = 2 tricks
P = 0-1 tricks (then partner doubles with 1 trick)

Other possibilities exist as well. The problem is the difficulty in actually assessing what a trick is. In general I have seen more disasters with these methods than successes but I daresay that with expert judgement they are effective.

In his book Doubles for Takeout, Penalties and Profit, Bob Ewen mentions the negative slam double. As of the time of writing the book, he said that such doubles had been employed against him three times, by expert opponents each time, and the results were:

Making 6 doubled,
Making 6 doubled, with an overtrick,
Having the opponents sacrifice in 7 when his slam was going down.

He recommends against their use, precisely because it is so difficult to tell what's going to be a defensive trick in such circumstances.